Epidermal acral acantholysis Localized loss of adhesion between the keratinocytes of the epidermis that selectively affects the distal regions of the extremities, causing blisters or vesicles located acrally. It is characteristic of specific variants of epidermolysis bullosa simplex.

Also: acral acantholysis · acral epidermal cell separation

Follicular epidermal acantholysis Break or loss of cohesion between the keratinocytes of the epithelial sheath of the hair follicle, secondary to the destruction of the desmosomes. It is frequently seen in autoimmune blistering diseases such as pemphigus vulgaris.

Also: follicular acantholysis · follicular dissociation

Follicular epidermal acantholysis of pemphigus vulgaris Loss of cohesion between the epithelial keratinocytes that line the outer root sheath of the hair follicle, secondary to antibodies directed against desmoglein 3. It facilitates the formation of deep and painful follicular intraepidermal vesiculation.

Also: pemphigus follicular acantholysis · follicular epidermal cleavage of pemphigus vulgaris

Superficial epidermal acantholysis Clavage or disunion of keratinocytes located selectively in the upper strata of the epidermis, specifically in the granular layer. Histologically it defines pemphigus foliaceus and clinically it causes very flaccid blisters that are easy to rupture.

Also: subcorneal acantholysis · superficial epidermal cleavage

Superficial epidermal acantholysis of pemphigus foliaceus Loss of intercellular adhesion between keratinocytes confined to the outermost layers of the epidermis, specifically in the granular or subcorneal layer, due to antibodies directed against desmoglein 1. It causes the formation of very flaccid blisters and crusty erosions.

Also: superficial cleavage of pemphigus foliaceus

Focal acantholysis Intercellular dissociation limited to small areas of the epidermis, with preservation of cellular cohesion in the rest of the epithelial tissue. This phenomenon is characteristic of entities such as Grover's disease and Darier's disease.

Also: segmental acantholysis · focal loss of epidermal cohesion

Grover's focal acantholysis Circumscribed intercellular separation of epidermal keratinocytes that temporarily compromises isolated areas of the stratum spinosum, respecting most of the cohesion of the tissue. It is the characteristic histological finding of transient acantholytic dermatosis.

Also: transient focal acantholysis · focal cleavage of Grover's disease

Grover's focal acantholysis of acantholytic dermatosis Circumscribed and focal intercellular separation of the keratinocytes of the stratum spinosum that is associated with mild cellular dyskeratosis, limited to small epidermal areas. It is the defining change of transient acantholytic dermatosis.

Also: Grover's acantholysis · focal cleavage of Grover's disease histology

Suprabasal cleft acantholysis Intercellular separation between keratinocytes that occurs immediately above the basal stratum of the epidermis, leaving a row of basal cells attached to the dermis with a "tombstone" appearance. It is the classic pathognomonic finding of pemphigus vulgaris.

Also: suprabasal cleavage · suprabasal acantholytic cleft

Irregular acanthosis Asymmetrical increase in the stratum of Malpighi with epidermal ridges of variable lengths and widths that penetrate disorderly into the dermis. It is frequently observed in chronic eczematous and lichenoid dermatitis.

Also: irregular epidermal hyperplasia · asymmetric epidermal thickening

Psoriasiform acanthosis Thickening of the epidermis characterized by a regular and symmetrical elongation of the interpapillary ridges, resembling the morphology of psoriasis vulgaris. Clinically it is associated with peeling and thickening of the skin plaque.

Also: psoriasiform hyperplasia · regular elongation of epidermal ridges

Regular acanthosis Uniform increase in the thickness of the stratum spinosum that maintains a homogeneous alignment in the depth of the epidermal ridges. It is a common reactive alteration in persistent inflammatory skin processes.

Also: regular epidermal hyperplasia · regular thickening of the Malpighian stratum

Regular psoriasiform acanthosis Uniform elongation of the epidermal ridges that penetrate the papillary dermis to the same depth, simulating the histological architecture of psoriasis. It causes thinning of the portions of epidermis over the dermal papillae.

Also: regular elongation of Malpighian ridges

Regular psoriasiform acanthosis of psoriasis Symmetrical elongation of the epidermal ridges that penetrate the papillary dermis at a uniform level, histologically associated with hypogranulosis and supraadjacent parakeratosis. It constitutes the characteristic histological substrate that defines the plaque of psoriasis vulgaris.

Also: regular psoriasiform hyperplasia · regular psoriasis acanthosis

Derm hemorrhagic blister Elevated lesion with predominantly blood content due to compromise or rupture of the underlying dermal capillaries. It is usually associated with severe trauma, necrotizing vasculitis or serious blistering pathologies.

Also: ampoule of blood content · hemorrhagic flictena

Acantholytic intraepidermal blister Cavitary lesion with liquid content located in the thickness of the epidermis, caused by the loss of desmosomal adhesion between keratinocytes. It is the defining histopathological finding of pemphigus.

Also: intraepidermal acantholytic cavity · acantholysis blister

Subepidermal stress blister Voluminous liquid collection located below the dermoepidermal junction, which preserves an intact and firm epidermal roof due to the preservation of the desmosomes. Clinically it is very resistant to spontaneous rupture and characterizes bullous pemphigoid.

Also: tense subepidermal blister · high-tension dermoepidermal vesicle

Keratinocyte anaplasia Loss of cellular differentiation and alteration of polarity in keratinocytes, with marked variability in cellular and nuclear size and shape. It is a histopathological sign of epithelial malignancy typical of squamous cell carcinoma.

Also: marked keratinocytic cellular atypia · cutaneous epithelial anaplasia

Elastolytic anetoderma Variety of circumscribed skin atrophy characterized by a localized and clinically perceptible loss of dermal elastic tissue, which gives the skin a herniated or flaccid appearance to the touch. It may be of primary origin or secondary to previous inflammatory processes.

Also: elastolytic macular atrophy · inflammatory anetoderma

Squamous cellular atypia Presence of epithelial keratinocytes with abnormal variations in their morphology, increased nucleus-cytoplasm ratio and atypical mitotic figures. It is considered a premalignant or malignant finding in epidermal neoplasms.

Also: squamous keratinocytic atypia · squamous cell pleomorphism

Epidermal koilocytic atypia Cellular alteration characterized by keratinocytes with hyperchromatic, wrinkled nuclei surrounded by a clear perinuclear halo due to the cytopathic effect of the human papillomavirus. It is identified in the upper granular and spinous stratum of warts.

Also: koilocytic vacuolization · koilocytic keratinocytes

Epidermal koilocytic atypia of verruca vulgaris Keratinocyte of the upper strata of the epidermis that presents a large, deformed and hyperchromatic nucleus surrounded by a large clear and empty cytoplasmic area due to infection by the human papillomavirus.

Also: verruca vulgaris coilocyte · koilocytic vacuolization by papillomavirus

Epidermal koilocytic atypia due to HPV Keratinocytic morphological alteration characterized by enlarged, wrinkled and hyperchromatic nuclei surrounded by a large clear cytoplasmic vacuole, due to human papillomavirus infection. It is preferentially located in the stratum granulosum.

Also: HPV vacuolization · viral wart koilocytes

Spitz's Atypia Nuclear alteration characterized by moderate pleomorphism, prominent nucleoli and occasional mitoses at the base of a benign melanocytic proliferation of spindle-cell or epithelioid cells. It is extremely important to differentiate it from the malignant atypia of melanoma.

Also: Spitzoid pleomorphism · Spitz nuclear atypia

Spitz atypia Spitz nevus cell Moderate morphological variability with the presence of large epithelioid and spindle cells with visible nucleoli located at the dermoepidermal junction of benign Spitz nevi. Unlike melanoma, it respects the symmetry of the lesion and matures in depth.

Also: Spitzoid atypia · spitz nevus pleomorphism

Spitz atypia spindle cell Spitz nevus Presence of large spindle-cell melanocytes with visible nucleoli and moderate cytological pleomorphism in the dermoepidermal portion of benign Spitz nevi, characterized by a symmetrical arrangement and wedge-shaped infiltration that matures in depth.

Also: Spitzoid spindle cell pleomorphism · Spitz spindle cell atypia

Advanced senile cutaneous atrophy Severe and generalized reduction in the thickness of the epidermis and dermis associated with intrinsic and extrinsic skin aging, with flattening of the dermoepidermal junction and loss of annexes. Clinically it is characterized by extreme fragility, dryness and propensity to senile purpura.

Also: atrophy of the skin of the elderly · severe skin aging

Dermal atrophy with loss of adnexa Severe thinning of the dermal collagen stroma that is accompanied by the disappearance or regression of the pilosebaceous follicles and sweat glands, replaced by bands of fibrosis. It is observed in terminal phases of scarring alopecia and scleroderma.

Also: cutaneous atrophy with adnexal loss · healing adnexal sclerosis

Morphea dermal atrophy in plaques Progressive thinning of the thickness of the papillary and reticular dermis due to hyalinization and compaction of collagen, with disappearance of perianexal fatty tissue and atrophy of sweat glands. It manifests clinically as a whitish plaque with a hard consistency.

Also: dermal atrophy of morphea · dermal sclerosis in plaques

Focal epidermal atrophy Localized thinning of the epidermis that entails the loss of the granular layers and a decrease in the number of layers of the stratum spinosum. Clinically it manifests itself as translucent, wrinkled and fragile skin.

Also: localized epidermal thinning · focal atrophy of the skin epithelium

Focal epidermal atrophy due to corticosteroids Localized thinning of the thickness of the epidermis induced by the chronic use of high-potency topical corticosteroids, characterized by flattening of interpapillary ridges and reduction of the stratum spinosum. Clinically, the skin acquires a translucent and fragile appearance.

Also: atrophy due to corticosteroids · epidermal thinning due to steroids

Focal epidermal atrophy due to topical corticosteroids Localized thinning of all layers of the epidermis induced by the inappropriate or prolonged use of high-potency topical steroid formulations, characterized by the loss of the stratum granulosum and flattening of epidermal ridges.

Also: atrophy due to topical steroids · epidermal atrophy due to local corticosteroids

Generalized senile epidermal atrophy Diffuse and progressive thinning of all layers of the epidermis associated with intrinsic aging of skin exposed and not exposed to the sun, histologically characterized by loss of the interpapillary ridge pattern. It presents with xerosis, paleness and susceptibility to ecchymoses due to minimal trauma.

Also: senile skin atrophy · diffuse senile skin thinning

Healing follicular atrophy Reduction and irreversible destruction of the epithelium of the hair follicles, which is replaced by cords of dense collagen, with definitive loss of the corresponding hair. It is the defining finding of conditions such as lichen planapilaris.

Also: follicular atrophy · follicular scarring alopecia

Cutaneous follicular atrophy Thinning or regression of the structures that make up the pilosebaceous follicle, replacing the follicular epithelium with fibrous scar tissue. It is clinically associated with scarring alopecia.

Also: destructive follicular regression · atrophy of hairy annexes

Follicular atrophy of follicular lichen planus Irreversible destruction of the epithelial root sheaths of the hair follicles due to lymphocytic immunological aggression, with subsequent follicular replacement by sclerotic connective tissue that obliterates the follicular pore. It is responsible for scarring alopecia in lichen planapilaris.

Also: lichen follicular atrophy · lichenoid scarring alopecia

Atrophoderma of Pasini and Pierini A form of localized skin atrophy that presents as depressed plaques with well-defined edges, called "cliff", with hyperpigmented skin and a normal consistency to the touch. It is considered a variant or phase of morphea.

Also: idiopathic atrophoderma · cliff skin atrophy · Pasini and Pierini cutaneous atrophy · localized scleroderma variant

Idiopathic atrophoderma of Pasini and Pierini Localized variant of benign skin atrophy that presents clinically as depressed plaques with defined "cliff-shaped" edges and a hyperpigmented or normal surface, predominantly affecting the trunk of young women. It does not cause collagen hardening.

Also: cutaneous atrophy in Pasini cliff

Linear atrophoderma of Moulin Uncommon dermatosis characterized by linear bands of depressed, hyperpigmented and atrophic skin that strictly follow Blaschko's lines, without previous induration or collagen sclerosis. It occurs unilaterally during childhood or adolescence.

Also: linear atrophoderma · atrophic bands of Moulin

Dermal leukocyte karyorrhexitis Destructive fragmentation of the nucleus of polymorphonuclear leukocytes inside or around the vessels of the dermis, generating basophilic debris known as nuclear dust. It is a fundamental finding in leukocytoclastic vasculitis.

Also: leukocyte nuclear fragmentation · karyorrhexis in dermis

Perivascular leukocyte karyorrhexitis of vasculitis Destruction and fragmentation of the nuclei of neutrophils that infiltrate the walls of the postcapillary venules of the upper dermis, producing abundant basophilic granules of nuclear dust. It is the confirmatory histological finding of leukocytoclastic vasculitis.

Also: vasculitis nuclear dust · dermal vascular leukocytoclasis

Dermal perivascular leukocyte karyorrhexitis Destructive cellular fragmentation of the neutrophilic polymorphonuclear leukocyte nuclei located around and in the walls of damaged dermal blood vessels, causing basophilic debris. It is the confirmatory histological sign of leukocytoclastic vasculitis.

Also: perivascular nuclear dust · karyorrhexis in vasculitis

Proliferated epidermal Langerhans cell Quantitative increase in antigen-presenting cells of the epidermis, with dendritic morphology and specific immunophenotype, which actively infiltrate the epithelium. It is characteristically observed in Langerhans cell histiocytosis with skin involvement.

Also: proliferation of cutaneous Langerhans cells · dendritic epidermal infiltrate

Epidermal shadow cell Modified keratinocyte that has lost its nucleus and shows a well-defined eosinophilic cytoplasm, preserving the cell silhouette in a ghostly manner. It is characteristic of pilomatricoma or calcifying epithelioma of Malherbe.

Also: ghost cell · mummified keratinocyte

Depressed atrophic scar Healing lesion characterized by a depression of the skin surface with respect to the level of the surrounding skin, due to the loss of collagen or subcutaneous tissue during the repair process. It is very common as a sequel to severe acne or chickenpox.

Also: depressed scar · focal healing atrophy

Depressed acne scar Secondary lesion characterized by a loss of dermal or subcutaneous tissue volume at the site of a previous inflammatory acne lesion, classified morphologically as "ice pick", "carriage train" or "rolling" scars. Requires collagen remodeling treatments.

Also: atrophic acne scar · atrophic sequelae of acne

Hypertrophic scar from surgical wound Fibrous lesion with a linear path, raised and with an erythematous-violet color, which develops along the line of a previous surgical incision, strictly limited to its margins. Histologically it shows collagen bundles arranged in a parallel direction.

Also: surgical hypertrophic scar · surgical false keloid

Dermal hypertrophic scar Raised and erythematous fibrous lesion that develops on the site of a previous skin injury, strictly confined to the limits of the original wound. Histologically, it presents collagen bundles parallel to the epidermis without the keloid disorder.

Also: hypertrophic scarring · depressed hypertrophic fibrous tissue

Hypertrophic dermoepidermal scar Raised, firm and erythematous scar lesion that is generated after a burn or deep wound, strictly confined to the area of original skin injury. Histologically it shows thin collagen bundles parallel to the surface of the skin.

Also: hypertrophic scar · delimited raised fibrous scar tissue

Auricular keloid scar Excessive fibrous proliferation of thick collagen located exclusively in the earlobe, usually secondary to trauma from earring piercings. It presents clinically as a lobulated, firm and persistent nodule that is very difficult to resolve therapeutically.

Also: ear lobe keloid · atrial keloid scar

Dermal keloid scar Excessive fibrous proliferation of thick, hyalinized collagenous tissue that extends significantly beyond the limits of the original skin wound, with a tendency to recurrence after excision. Clinically it is pruritic, painful and firm.

Also: true cutaneous keloid · expansive keloid scarring

Expanding dermal keloid scar Abnormal fibroblastic proliferation with excessive deposition of thick, acellular and hyalinized collagen bundles that extends notably beyond the margins of the original wound, showing resistance to treatment. It presents clinically with persistent pain and pruritus.

Also: cutaneous keloid · true keloid scar

Expanding dermal keloid scar of keloid Persistent fibrous proliferation consisting of very thick, acellular, hyalinized and disorganized collagen bundles that protrude significantly from the skin and extend beyond the area of the original wound, with an itchy and painful evolution.

Also: true keloid · thick collagen keloid scar

Open keratotic comedo Dilated pilosebaceous follicle obstructed by dehydrated keratin and oxidized lipids, whose distal portion exposed to air acquires a characteristic dark or black color. It is a very common elemental lesion in acne vulgaris.

Also: black comedone · black point

Obstructive closed comedo Primary acneic lesion constituted by a keratose and lipid plug in the follicular infundibulum that lacks a visible opening to the outside, presenting as a small whitish papule. It is the direct precursor of inflammatory acne lesions.

Also: white comedone · white point

Facial obstructive closed comedo Small whitish or yellowish non-inflammatory subepidermal papule constituted by the retention of keratin and sebum in the distended follicular duct that lacks visible communication with the outside. It is the comedo that most frequently evolves into inflammatory lesions.

Also: closed comedo · whitehead acne

Acne facial obstructive closed comedo Small non-inflammatory, whitish-colored, subepidermal cupuliform papule, constituted by infundibular obstruction of the pilosebaceous follicle by dehydrated keratin and retained sebum without visible opening. It is the precursor lesion of papulopustular acne.

Also: whitehead facial acne

Favre-Racouchot senile comedo Large non-inflammatory acneic lesion consisting of a dilated follicle filled with compact keratin and lipids, located in areas of skin with severe solar elastosis in elderly male patients. It is characteristic of the periocular and temple region.

Also: Favre-Racouchot actinic comedo · senile comedo of Favre and Racouchot

Senile sun comedo Large comedo located in facial areas of atrophic skin and with severe solar elastosis of elderly patients, typically free of active acneic inflammatory component. It is part of the clinical spectrum of Favre-Racouchot syndrome.

Also: senile actinic comedo · Favre-Racouchot comedone

Annular skin configuration Arrangement of primary or secondary elementary lesions that form a ring with a clear or normal-appearing center and raised active edges. It is typical of tinea corporis and erythema annulare centrifuge.

Also: annular distribution · cutaneous ring pattern

Centrifugal cutaneous annular configuration Arrangement of erythematous papules or plaques that grow progressively towards the periphery while showing clinical resolution of their central area, forming rings with well-defined edges. It is typical of erythema annulare centrifuge and granuloma annulare.

Also: centrifugal annular distribution · centrifugal ring pattern

Cutaneous annular configuration of granuloma annulare Arrangement of firm papules of cutaneous or erythematous-violaceous color that are grouped in a circle forming an annular plaque with an undamaged or discretely depressed center, characteristic of localized granuloma annulare.

Also: granuloma annulare distribution · annular pattern of granuloma annulare

Centrifugal configuration Lesion that experiences progressive growth towards the periphery, moving away from the point of origin, which simultaneously tends to resolution or clinical attenuation. It is common in fungal infectious processes and reactive erythema.

Also: centrifuge extension · peripheral dispersion

Circinated configuration Lesional pattern in which incomplete circles or arcs of circles are grouped in an orderly manner on the skin surface, suggesting eccentric growth. It is associated with inflammatory pathologies and chronic dermatophytosis.

Also: circinated arrangement · semicircle distribution

Corymbiform configuration Lesional grouping characterized by a large central lesion surrounded by multiple smaller peripheral satellite lesions, resembling the fall of a cluster or an inflorescence. It is classically described in secondary syphilis.

Also: corymbose distribution · satellite pattern

Targetoid target configuration Circular skin lesion composed of at least three morphologically distinct concentric zones: a purpuric or vesicular center, a pale intermediate ring, and an external erythematous border. It is the pathognomonic clinical finding of erythema multiforme.

Also: injury on cockade · dermatological target

Herpetiform configuration Group of small vesicles of uniform size arranged in clusters on a common erythematous base, similar to the typical presentation of herpes simplex virus infections. It is classically associated with herpes and dermatitis herpetiformis.

Also: cluster distribution · herpetiform pattern

Clustered herpetiform configuration Lesional arrangement in which small vesicles of homogeneous size are closely grouped in clusters on patches of erythematous or edematous skin, imitating the morphology of herpes simplex. It is associated with viral infections and Duhring's dermatitis herpetiformis.

Also: herpetiform grouping · vesicles in herpetiform cluster

Herpetiform configuration of dermatitis herpetiformis Group of small vesicles of uniform size arranged closely in clusters or erythematous patches of symmetrical distribution on extensor surfaces, associated with gluten-sensitive enteropathy. It causes extreme burning itching.

Also: clustered Duhring vesicles · Duhring's herpetiform distribution

Linear configuration Distribution of elementary skin lesions that are arranged forming a straight line or continuous filiform path, often secondary to the Koebner phenomenon or progression along Blaschko's lines. It is seen in linear lichen planus and plant contact dermatitis.

Also: cutaneous linear pattern · linear lesion distribution

Blaschko linear configuration Arrangement of elementary skin lesions that adopt a linear, arcuate or swirling pattern strictly following the lines of embryonic development of the epidermis or Blaschko lines. It is identified in linear epidermal nevus and lichen striatus.

Also: Blaschko linear pattern · blaschkoid distribution

Blaschko linear configuration of epidermal nevus Arrangement of hyperchromic keratotic papules or plaques that adopt a linear morphology or arcuate bands following the embryonic lines of Blaschko on the trunk or extremities. It is characteristic of linear verrucous epidermal nevus.

Also: blaschkoid epidermal nevus · Blaschko linear distribution of nevo

Numular configuration Distribution of elementary skin lesions that adopt a circular or oval morphology of medium size and well-defined edges, resembling the shape of a coin. It is the defining lesion of nummular eczema.

Also: discoid eczema · currency distribution

Polycyclic configuration Lesion distribution resulting from the coalescence of multiple circular or annular lesions, causing scalloped edges with the morphology of several interlocking semicircles. It is very characteristic of urticaria and cutaneous drug reactions.

Also: polycyclic distribution · cutaneous scalloped pattern

Lattice configuration Lesional arrangement in the form of a mesh, network or lace that draws a diffuse geometric or mottled pattern on the skin, often reflecting alterations in dermal microcirculation. It is characteristic of livedo reticularis and erythema ab igne.

Also: network distribution · skin lace pattern

Erythematous-violet reticulated configuration Arrangement of vascular or pigmented lesions that draw a mesh, network or pattern in a continuous lace on the skin, reflecting functional or structural alterations of the dermal capillary plexus. It is the defining clinical manifestation of livedo reticularis.

Also: cutaneous reticulated pattern · violet network distribution

Erythematous-violet reticulated configuration of livedo Skin vascular pattern that adopts a network, mesh or continuous lace morphology of violet color, caused by the alteration of blood perfusion in the microarterioles of the dermis. It is accentuated by exposure to cold.

Also: livedo reticularis distribution · erythematous-violet network pattern

Serpiginous configuration Arrangement of lesions that advance in a sinuous or undulating manner, healing at one end while actively progressing along the opposite edge, resembling the path of a snake. It is typical of cutaneous larva migrans and some ringworms.

Also: winding pattern · serpiginous distribution

Zosteriform configuration Unilateral distribution of elementary dermatological lesions, typically papules, vesicles or scabs, arranged along the path of a cutaneous sensory dermatome. It is the classic and defining presentation of herpes zoster.

Also: dermal distribution · zosterian pattern

Dry scaly scab Secondary lesion constituted by the mixture of debris from the desquamated stratum corneum with little dry serous exudate, forming a thin, grayish and brittle plaque on the inflamed skin. It is associated with chronic eczema in the dry peeling phase.

Also: scaly scab · scaly-crusty plaque

Dry epidermal scaly scab Superficial solid concretion constituted by the compaction of desquamated keratinocytes from the stratum corneum mixed with little dehydrated serum on an inflamed skin surface. Indicates a resolution or subacute phase of eczematous processes and irritative dermatitis.

Also: dry scaly scab · epidermal peeling scab

Hematic scab from scratching atopic dermatitis Desiccated dark reddish-brown plaque that originates from the coagulation of extravasated blood from the exposed papillary dermis due to intense linear scratching in patients with atopic dermatitis. Indicates the presence of intractable pruritus.

Also: atopic scratching hemorrhagic scab · atopic blood scab

Dried blood scab Solid superficial plaque of reddish or dark brown color, formed by the drying of extravasated blood and cellular debris on a previously eroded skin surface. Its presence indicates active scratching or previous dermoepidermal trauma.

Also: blood scab · hemorrhagic scab

Post-traumatic blood scab Desiccated and firm dark brown plaque that forms on eroded skin due to coagulation and drying of extravasated blood after scratching or superficial trauma. Its early detachment can induce minor pinpoint bleeding.

Also: traumatic hemorrhagic scab · crust of dried blood

Meliceric scab of contagious impetigo Solid and superficial concretion of translucent yellow color, composed of dried exudate rich in serum, proteins, bacteria and remains of polymorphonuclear leukocytes. It represents the pathognomonic clinical sign of non-bullous impetigo vulgaris.

Also: honey-colored bacterial scab

Meliceric scab of contagious bacterial impetigo Superficial solid concretion similar in appearance to dried honey, formed by the drying of serous exudate rich in proteins, neutrophils and colonies of gram-positive bacteria on previously eroded skin. It is the defining lesion of Tilbury-Fox impetigo.

Also: bacterial meliceric crust of impetigo

Meliceric scab of contagious staphylococcal impetigo Solid and superficial concretion of translucent yellow color similar to dried honey, formed by the rapid drying of purulent exudate rich in proteins and gram-positive bacteria in non-bullous impetigo. It is the defining lesion of Staphylococcus aureus infection.

Also: staphylococcal impetigo scab · meliceric Bockhart scab

Tilbury-Fox meliceric scab of impetigo Solid and superficial concretion of translucent yellow color similar to dried honey, constituted by the drying of seropurulent exudate rich in proteins on skin erosions. It is the pathognomonic secondary elementary lesion of contagious impetigo.

Also: honey-colored scab of impetigo · streptococcal meliceric scab

Infectious meliceric scab Plaque of semi-solid consistency and translucent yellowish color similar to honey, caused by the drying of a serous or purulent exudate rich in bacteria. It is the classic and diagnostic secondary lesion of contagious impetigo.

Also: honey-colored scab · meliceric scab of impetigo

Thick purulent crust Solid superficial concretion formed by the desiccation of pus rich in polymorphonuclear leukocytes and necrotic cellular debris, yellowish green or opaque. Its presence indicates an underlying active bacterial infectious process.

Also: purulent scab · crust of dried pus

Thick purulent ektima scab Thick, adherent, crusty plaque with a greenish-brown color, formed by the desiccation of pus and necrotic cellular remains that covers a deep ulcer in the dermis. It is associated with deep streptococcal infections and poor hygiene.

Also: ektima scab · necrotic purulent scab

Thick purulent crust of bacterial ektima Thick, very adherent, greenish-brown, crusty plaque formed by the desiccation of purulent and cellular remains that completely covers a deep ulcer infected by Streptococcus pyogenes.

Also: deep purulent ektima crust

Adherent serohematic scab Superficial solid concretion formed by the joint desiccation of serous plasma and red blood cells on an inflammatory or excoriated skin lesion, which acquires an intermediate yellowish-brown color. It is a very common secondary finding in active atopic dermatitis.

Also: serohematic scab · mixed serum and blood scab

Interface epidermal colloid body Round, acidophilic structure rich in modified keratin located in the lower epidermis or papillary dermis, caused by the degeneration and cell death of keratinocytes. It is associated with interface pathologies and lupus erythematosus.

Also: dermal cytoid body · colloid body

Epidermal Civatte Body Apoptotic keratinocyte of basal or suprabasal location that appears as a spheroidal, eosinophilic and anucleated structure in the histopathological study. It is characteristic of inflammatory pathologies with interface dermatitis such as lichen planus.

Also: Civatte colloid body · interphase apoptotic keratinocyte

Acidophilic Kamino body Eosinophilic spheroidal structure, PAS positive and rich in basement membrane and cellular debris, located in the dermal papillae or the dermoepidermal junction of benign melanocytic lesions. It is very useful diagnostically to identify Spitz nevus.

Also: Kamino globule · Kamino's body

Acidophilic Kamino body of Spitz nevus Eosinophilic spheroidal structure, PAS positive and with well-defined contours, characteristically located at the dermoepidermal junction of benign Spitz nevi. It is composed of disorganized basement membrane proteins and damaged keratinocytes.

Also: Spitz nevus Kamino body

Kamino body of benign Spitz nevus Eosinophilic spheroidal structure, PAS positive and with a clear contour located selectively in the dermal papillae or dermoepidermal junction of Spitz nevi. It is made up of damaged keratin filaments and basement membrane proteins.

Also: Spitz's Kamino globule · Kamino body of Spitz nevus histology

Epidermal Kamino body Eosinophilic and rounded globule of basement membrane material located in the basal intraepidermal portion of Spitz nevi, of great importance to differentiate them histologically from malignant melanoma in the pathological examination. It is a characteristic histological finding of benign Spitzoid lesions.

Also: union Kamino body · intraepidermal Kamino globule

Epidermal Kamino body of Spitz nevus Eosinophilic and PAS-positive rounded globule made up of disorganized basement membrane material and keratinocyte debris, located selectively in the basal intraepidermal portion of Spitz nevi. It is useful to verify the benignity of the lesion.

Also: spitz intraepidermal Kamino globule

Epidermal ballooning degeneration Cellular alteration in which keratinocytes experience severe swelling, rounding and losing their intercellular connections, which causes acantholysis without initial necrosis of the cell. It is very characteristic of herpesvirus viral infections and some drug reactions.

Also: balloon degeneration · keratinocyte balloonization

Epidermal ballooning degeneration of herpes Severe swelling and rounding of the keratinocytes of the epidermis due to acute intracellular edema due to viral infection, which leads to cell separation and formation of intraepidermal vesicles. It is the pathognomonic finding of herpes virus infection.

Also: herpes ballooning · herpetic cellular degeneration

Epidermal ballooning degeneration of chickenpox Extreme swelling and rounding of keratinocytes infected by the varicella-zoster virus that lose desmosomal cohesion and lyse, contributing to the formation of an umbilicated intraepidermal vesicle. Course with nuclear inclusions.

Also: ballooning for chickenpox · chickenpox cellular degeneration histology

Viral ballooning degeneration Extreme swelling and progressive vacuolization of the cytoplasm of individual keratinocytes infected by herpesviruses, which lose their desmosomal attachments and float inside an epidermal vesicle. It is histologically accompanied by multinucleated giant cells.

Also: virus ballooning · cellular degeneration due to herpesvirus

Hydropic degeneration of the dermal basal layer Histopathological alteration characterized by the formation of small fluid vacuoles inside or around the keratinocytes of the basal stratum of the epidermis. It causes the destructuring of the dermoepidermal junction and is typical of lupus erythematosus and lichen planus.

Also: hydropic degeneration of the basal · basal epidermal vacuolar alteration

Hydropic degeneration of the interface Severe intercellular and intracellular edema selectively located at the dermoepidermal junction, which destroys the basal line of keratinocytes and favors the formation of clefts or small vesicles due to cleavage. It is the elemental alteration of lupus interface dermatitis.

Also: vacuolar alteration of the interface · degeneration of the dermoepidermal junction

Epidermal reticular degeneration Severe intracellular edema that produces the bursting and lysis of keratinocytes, leaving a network of cell membranes that resembles a network. It is typical of acute viral infections in the epidermis.

Also: reticular degeneration · epidermal lysis due to edema

Basal vacuolar degeneration Histological alteration characterized by the presence of fluid vacuoles that form within or just below the basal cells of the epidermis, disorganizing the dermoepidermal junction. It is a primary sign of cellular aggression in lupus and lichen planus.

Also: basal liquefaction · basal epidermal vacuolization

Dystrophic cutaneous calcareous deposit Abnormal precipitation of phosphate salts and calcium hydroxide in the dermis or previously injured subcutaneous tissue, with normal serum calcium and phosphorus levels. It is observed in chronic inflammatory processes, collagenopathies and old scars.

Also: dystrophic calcinosis cutis · dermal calcium deposit

Metastatic cutaneous calcareous deposit Abnormal precipitation of calcium salts in the dermis and subcutaneous cellular tissue associated with systemic metabolic alterations that cause elevation of the calcium-phosphorus product or hypercalcemia. It is seen in hyperparathyroidism and end-stage chronic renal failure.

Also: metastatic calcinosis cutis · metastatic skin calcification

Dermal calcareous deposit of calcinosis Abnormal accumulation of insoluble calcium salts in the stroma of the papillary or reticular dermis, manifesting clinically as very hard whitish papules or nodules that can extrude through the epidermis. It is associated with dermatomyositis and scleroderma.

Also: calcinosis cutis · calcium deposit in the dermis

Dermal calcareous deposit of cutaneous calcinosis Precipitation and accumulation of insoluble calcium salts in the form of amorphous and basophilic material in the upper dermis or subcutaneous cellular tissue, manifesting as hard nodules that can be extruded. It is associated with collagenopathies and trauma.

Also: calcinosis cutis histology · calcification of the dermis of calcinosis

Papillary dermal amyloid deposit Extracellular accumulation of amorphous fibrillar protein material in the dermal papillae, which stains with Congo Red and shows apple green birefringence under polarized light. It is classically associated with cutaneous macular and lichenoid amyloidosis.

Also: dermal amyloid · papillary amyloid deposit

Perivascular fibrin deposition Homogeneous and eosinophilic accumulation of fibrin around and within the walls of the vessels of the dermis, which denotes acute endothelial damage. It is a key histopathological sign for the diagnosis of active cutaneous vasculitis.

Also: perivascular fibrin · vascular fibrinoid deposition

Interface dermatitis Dermal-epidermal inflammation in which the inflammatory infiltrate is located on the basal layer of the epidermis, altering its structure and inducing necrosis of individual keratinocytes. It is typically seen in lupus, erythema multiforme, and drug reactions.

Also: inflammation of the dermoepidermal junction · basal lymphocytic aggression

Lichenoid interface dermatitis Pattern of cutaneous inflammation histologically defined by a dense lymphoid inflammatory infiltrate arranged in a band that erases the dermoepidermal junction, accompanied by basal vacuolization. It is the defining morphological finding of lichen planus and related eruptions.

Also: lichenoid dermatitis · inflammatory infiltrate in dermoepidermal band

Lichenoid interface dermatitis of lichen planus Lymphohistiocytic inflammatory infiltrate arranged in a continuous horizontal band in the papillary dermis, which attacks the basal layer of the epidermis, producing basal liquefaction and apoptotic bodies. It is the defining morphological finding of lichen planus.

Also: lichenoid dermatitis of lichen planus · lymphoid infiltrate in the junctional band

Band lichenoid interface dermatitis Histological pattern of skin damage in which a dense infiltrate of mature lymphocytes is arranged in a continuous band that confluently erases the dermoepidermal junction, accompanied by basal vacuolization. It is typical of lichen planus and lichenoid reactions.

Also: interface lichenoid dermatitis · lymphoid infiltrate in dermoepidermal band

Vacuolar interface dermatitis Histopathological pattern of cutaneous inflammation characterized by scant or diffuse lymphoid infiltrate associated with marked vacuolar degeneration of basal keratinocytes and formation of apoptotic bodies. It is typically identified in systemic lupus erythematosus, erythema multiforme, and dermatomyositis.

Also: non-lichenoid interface dermatitis · junctional vacuolar dermatitis

Ischemic white dermographism Appearance of a pale or whitish line on healthy skin after moderate friction with a blunt object, secondary to abnormal capillary reflex vasoconstriction. It is an atypical skin response highly characteristic of patients with atopic dermatitis.

Also: pale dermographism · atopic friction vasoconstriction

Active erythematous dermographism Rapid appearance of a raised and edematous bright red erythema on the skin in response to friction or mild scratching, mediated by a local axonal reflex and mast cell degranulation. It differs from spontaneous urticarial plaques by being mechanically inducible.

Also: active red dermographism · physical urticaria due to erythematous scratching

Active erythematous dermographism due to urticaria friction Bright red linear erythematous and edematous elevation that appears immediately on the skin subjected to mild pressure or friction, secondary to the release of histamine by dermal mast cells. It is one of the most common forms of inducible urticaria.

Also: red dermographism of urticaria

Active erythematous dermographism due to scratching Rapid appearance of raised erythema with defined edges and a bright red color on the skin subjected to mild mechanical friction, mediated by mast cell degranulation and local axonal reflex. It disappears spontaneously in a few minutes without leaving a trace.

Also: physical hives due to friction

Passive erythematous dermographism Phenomenon characterized by the appearance of erythema of a certain duration or a whey-like elevation on the skin after applying a force of friction or gentle scratching to it. It is considered a common form of inducible physical urticaria.

Also: red dermographism · erythematous factitious urticaria

Peeling in epidermal collarette Marginal skin detachment that forms a circular scaly border around the perimeter of a previous erythematous or papular lesion, pointing towards the center. It is very characteristic of Gibert's pityriasis rosea and secondary syphilis.

Also: flaking necklace · scale on necklace

Diffuse exfoliative peeling Generalized detachment of the epidermal stratum corneum in the form of large sheets or flaps of skin, affecting extensive body surfaces. It is characteristic of erythroderma and the late stages of staphylococcal scalded skin syndrome.

Also: diffuse skin exfoliation · generalized lamellar peeling

Membranous lamellar desquamation Detachment of the horny layer of the skin in the form of extensive membranes or large continuous sheets, which leave an underlying erythematous and moist surface. It is the classic peeling observed in newborn collodion or after severe sunburn.

Also: membranous exfoliation · flaking in sheets

Pityriasiform peeling Epidermal detachment in the form of small, fine, dry, floury and whitish scales, which easily detach from the surface of the skin. It is the typical peeling seen in pityriasis versicolor and pityriasis rosea.

Also: mealy flaking · pityriasiform scales

Whityriasiform peeling Fine, furfuraceous detachment of particles from the stratum corneum that acquire a whitish or grayish hue and are easily detached when gently scraping the lesion. It is characteristically seen in pityriasis rosea and dermatitis sicca.

Also: fine whitish peeling · dry pityriasiform scale

Pityriasiform peeling of pityriasis rosea Fine, dry, marginal detachment of whitish scales that form a peripheral scaly border on an oval-shaped erythematous lesion, oriented along the tension lines of the skin. It is the classic peeling of the heraldic plate and secondary lesions of pityriasis rosea.

Also: Gibert's peeling · necklace scale of pityriasis rosea

Thick psoriasiform scaling Stratified, pearly or chalky-looking scales, adherent and arranged in plaques on markedly erythematous lesions. Its detachment reveals the characteristic spark plug sign or Auspitz bloody dew.

Also: micaceous peeling · psoriasiform pearly scale

Unctuous seborrheic peeling Yellowish, greasy, soft, variable-sized scales that moderately adhere to the markedly erythematous skin of areas rich in sebaceous glands such as the scalp and face. It is the defining secondary lesion of active seborrheic dermatitis.

Also: seborrheic scale · yellowish greasy flake

Infundibular follicular duct dilation Abnormal anatomical enlargement of the upper portion of the pilosebaceous follicle canal, frequently occupied by dense keratotic plugs or sebaceous debris. Clinically it manifests itself as dilated pores or giant comedones.

Also: dilated follicular duct · follicular infundibular dilation

Sweat duct dilation Enlargement of the lumen of the ducts of the eccrine or apocrine sweat glands due to distal keratotic obstruction, which clinically favors sweat retention and the appearance of miliaria vesicles. It may be associated with peri-ductal neutrophilic inflammation.

Also: eccrine duct dilation · sweat duct ectasia

Intraepithelial pagetoid spread Pattern of upward migration of atypical tumor cells, with abundant and clear cytoplasm, which infiltrate individually or in nests the upper strata of the epidermis. It is typically described in mammary and extramammary Paget's disease.

Also: epidermal pagetoid infiltration · pagetoid intraepidermal spread

Melanocytic pagetoid dissemination Abnormal migration or infiltration of atypical melanocytes into the upper layers of the epidermis, instead of remaining confined to the dermoepidermal junction. It is a major histopathological criterion for the diagnosis of superficial spreading melanoma.

Also: pagetoid migration of melanocytes · pagetoid intraepidermal dispersion

Dyskeratosis Abnormal and premature keratinization of epithelial keratinocytes before reaching the stratum corneum, manifesting histologically as intensely eosinophilic cells with pyknotic nuclei. It is observed in neoplastic processes and in diseases such as Darier's disease.

Also: abnormal individual keratinization · dyskeratotic cell death

Follicular acantholytic dyskeratosis Histopathological alteration characterized by premature and individual keratinization of keratinocytes within the epidermis, associated with the loss of desmosomal adhesion in the follicular duct. It is seen diagnostically in Darier's disease.

Also: premature acantholytic keratinization · follicular dyskeratosis

Hereditary acantholytic dyskeratosis Genetic disorder of keratinization characterized by the presence of prematurely keratinized individual keratinocytes associated with widespread suprabasal acantholytic clefts in the epidermis. It is the defining finding of hereditary Darier disease.

Also: Darier dyskeratosis · familial premature keratinization by Darier

Hereditary Darier epidermal dyskeratosis Presence of prematurely individually keratinized keratinocytes in the upper stratum spinosum of the epidermis, which acquire a rounded appearance with shiny eosinophilic cytoplasm and pyknotic nucleus. It is characteristic of Darier's disease.

Also: dyskeratotic keratinocyte of Darier · Darier dyskeratosis histology

Epidermal dyskeratosis of Darier disease Premature and individual keratinization of the keratinocytes located in the upper stratum spinosum, which acquire a rounded and shiny eosinophilic appearance known histologically as "round bodies". It is the defining finding of Darier disease.

Also: dyskeratotic keratinocytes of Darier · hereditary follicular dyskeratosis

Individual epidermal dyskeratosis Early and anomalous keratinization of individual cells of the stratum spinosum and granulosum, which acquire a bright eosinophilic cytoplasm and pyknotic nuclei. It is an indicator of genetic or cellular damage in neoplastic or viral processes.

Also: individual dyskeratosis · individual dyskeratotic keratinocytes

Malpighian intercellular edema Excessive accumulation of serum or interstitial fluid between the keratinocytes of the Malpighian stratum of the epidermis, which stretches the desmosomes giving a prickly appearance. It is the histopathological basis of acute eczema and is associated with the formation of vesicles.

Also: marked epidermal spongiosis · Malpighian interepidermal edema

Elastolysis of the middle dermis Specific pattern of skin atrophy characterized by the selective disappearance of elastic fibers in the middle band of the dermis, sparing the papillary and deep dermis. Clinically it manifests itself as patches of finely wrinkled, aged-looking skin.

Also: middle dermal elastolysis · elastic atrophy of the middle dermis

Localized dermal elastolysis Selective and localized loss or destruction of elastic fibers in the reticular or papillary dermis due to enzymatic or inflammatory action. Clinically it results in areas of sagging, wrinkled skin or circumscribed herniation.

Also: localized skin elastolysis · focal destruction of elastic fibers

Reticular dermal elastolysis Selective destruction or fragmentation of the elastic fibers located in the deep reticular dermis due to inflammatory, infectious or idiopathic processes. Clinically it results in a loss of turgor and elasticity of the skin, leading to sagging.

Also: reticular elastolysis · loss of elastin in reticular dermis

Solar dermal elastosis Degenerative alteration of collagen and elastic tissue in the upper dermis induced by chronic exposure to ultraviolet radiation, appearing as amorphous basophilic material in histology. Clinically it is associated with thickened, yellowish skin with deep grooves.

Also: actinic elastosis · solar elastic degeneration

Solar dermal elastosis of exposed skin Degenerative alteration of collagen and elastic fibers in the upper dermis caused by accumulated ultraviolet radiation, which histologically appears as patches of disorganized and amorphous basophilic material. Clinically it produces deep wrinkles and skin thickening.

Also: solar elastic degeneration of the dermis

Solar dermal elastosis of photoexposed skin Degenerative alteration induced by ultraviolet radiation characterized by the deposit of abnormal, basophilic, thickened and disorganized elastic fibers in the upper dermis, respecting a thin subepidermal band. It has deep wrinkles.

Also: actinic elastosis histology · solar elastic degeneration of the upper dermis

Superficial epidermal erosion from scratching Partial loss of the superficial layers of the epidermis that does not affect the dermal-epidermal junction, caused by mild mechanical trauma of the nails on the itchy skin. Heals quickly by epithelial regeneration without leaving a scar.

Also: erosion due to surface scratching · focal epidermal loss due to friction

Superficial epidermal erosion from scratching eczema Partial loss of the upper layers of the epidermis that does not reach the dermis, caused by repeated mechanical scratching to relieve itching in active eczematous processes. It quickly becomes covered with a serous crust.

Also: eczema scratching erosion · focal epidermal loss due to friction dermatitis

Focal superficial epidermal erosion Partial loss of the superficial layers of the epidermis, usually limited to the upper stratum corneum or spinosum, which heals without leaving a scar as it does not affect the basement membrane. It occurs after the rupture of superficial vesicles or due to slight friction.

Also: superficial exulceration · loss of superficial epidermal substance

Traumatic epidermal erosion Loss of superficial epidermal integrity of acute mechanical origin, such as minor abrasions or scrapes, which does not compromise the dermis and heals quickly by re-epithelialization without leaving a residual scar. Clinically it is covered with a fine serous crust.

Also: traumatic erosion · superficial epidermal abrasion

Steroidal acneiform eruption Monomorphic follicular papulopustular dermatosis of sudden onset, located preferably on the chest and back, induced by prolonged use or high doses of systemic or topical corticosteroids. It is histologically differentiated from acne vulgaris by the relative absence of comedones.

Also: steroid acne · corticosteroid-induced acneiform eruption

Follicular acneiform eruption Dermatosis characterized by the sudden appearance of monomorphic follicular papules and pustules, without accompanying comedones, typically triggered by drugs such as corticosteroids, lithium or EGFR inhibitors. It clinically differentiates from acne vulgaris due to its lesion uniformity.

Also: acneiform follicular eruption · monomorphic drug acne

Lamellar exfoliative scale Flat and thin epidermal fragments of medium to large size that spontaneously detach from the skin surface, denoting extremely accelerated epidermal cell turnover. It is very common in the resolution phases of scarlatiniform exanthems.

Also: exfoliating lamellar peeling · free lamellar scale

Fine furfuraceous scale Detachment of the stratum corneum into very small, whitish and volatile particles, similar to bran or fine dandruff, which fall with the friction of clothing. It is associated with dry eczema, seborrheic dermatitis and moderate cutaneous xerosis states.

Also: fine floury flaking · furfuraceous scale

Adherent laminar flake Detachment of keratinocytes in the form of large, horny sheets firmly adhered to the surface of the erythematous skin, difficult to separate without causing bleeding. It is the defining lesion of ichthyosiform processes and severe psoriasis.

Also: thick laminar flake · adherent scaly sheet

Adherent lamellar scale of ichthyosis Large-sized fragments of the stratum corneum, polygonal, dry and firmly adhered to the skin surface, resembling fish or reptile scales. It is caused by a genetic defect in keratinocyte shedding.

Also: ichthyosiform scale · compact lamellar scale of ichthyosis

Pearly lamellar scale Large, shiny, silvery or pearly scales, arranged in a stratified manner on a markedly erythematous base, characteristic of the epidermal hyperproliferative process of psoriasis vulgaris. Its dermoepidermal separation produces positive scraping.

Also: silver scale of psoriasis · pearly micaceous scale

Purulent moist necrotic eschar Area of soft, edematous skin necrosis, yellowish or greenish in color and with purulent detachment of debris due to active bacterial superinfection. Requires immediate surgical debridement to allow subsequent tissue granulation.

Also: purulent moist eschar · moist necrotic tissue

Dry necrotic eschar of ischemia Hard, black, dry, parchment-like plaque of necrotic skin tissue, firmly adhered to the underlying planes due to arterial occlusion of an area of the skin. It is the typical morphological manifestation of dry gangrene or advanced arterial ulcers.

Also: ischemic dry eschar · dehydrated necrotic plaque

Dry necrotic eschar from vascular ischemia Hard, black and dry plaque of skin tissue devitalized by complete arterial ischemia, firmly adhered to the deep planes, which acts as a barrier to healing. It is characteristic of dry gangrene and arterial ulcers.

Also: dry ischemia eschar · arterial dehydrated necrotic plaque

Delimited dry necrotic eschar Hard, black, dehydrated plaque strongly adhered to the deep planes, formed by cell death of the epidermis and dermis in an area of localized skin ischemia. It is characteristically seen in stable pressure ulcers and dry gangrene.

Also: dry eschar · mummified necrotic tissue

Dermal collagen sclerosis of morphea Dense compaction and marked thickening of the dermal collagen bundles that are arranged parallel to the epidermis, associated with progressive atrophy of the skin annexes and hardening of the skin. It is the defining histological alteration of morphea.

Also: morphea sclerosis · collagen compaction in morphea

Active morphea dermal collagen sclerosis Active phase of induration characterized by an increase in the synthesis and dense compaction of collagen bundles in the upper and middle dermis, which are arranged parallel to the epidermis with loss of annexes.

Also: active sclerosis morphea · compaction of morphea dermal collagen

Deep dermal collagen sclerosis Induration and pathological thickening of the dermis due to the massive increase and dense compaction of the collagen bundles, with obliteration of the interstitial spaces. Clinically, the skin becomes rigid, adhered to deep planes and difficult to pinch, as occurs in scleroderma.

Also: deep dermal sclerosis · compaction of dermal collagen

Deep hyaline collagen sclerosis Compaction and hyalinization of collagen bundles that compromise the deep dermis and peri-adnexal connective tissue, significantly limiting skin mobility. It is classically associated with late stages of morphea and systemic sclerosis.

Also: deep collagen sclerosis · deep dermal hyalinization

Deep collagen sclerosis of linear morphea Marked induration and thickening of the collagen of the deep reticular dermis and septa of the subcutaneous tissue, which adopts a linear morphology following anatomical paths or Blaschko's lines. It presents with underlying muscle atrophy and skin fixation.

Also: linear morphea · linear sclerosis of the skin

Superficial collagenous sclerosis of lichen sclerosus Dense hyalinization of the collagen fibers of the papillary dermis that acquire a homogeneous, bright eosinophilic and acellular appearance in the histological study, located under an atrophic epidermis. It is clinically associated with whitish pearly plaques.

Also: superficial dermal hyalinization · lichen sclerosus sclerosis

Superficial collagen sclerosis of genital lichen sclerosus Dense and acellular hyalinization of the papillary dermis located in the skin of the anogenital region, which acquires a homogeneous eosinophilic appearance under an atrophic epidermis that has lost its pattern of interpapillary ridges. It causes pruritus and painful anatomical stenosis.

Also: genital lichen sclerosus histology · papillary sclerosis of vulvar lichen sclerosus

Superficial collagenous sclerosis of lichen sclerosus Dense hyalinization and homogenization of collagen fibers selectively located in the papillary dermis, just below an atrophic epidermis with hyperkeratosis. Histologically it shows a band of edema or underlying lymphoid infiltrate.

Also: hyaline papillary sclerosis · superficial dermal hyalinization of lichen sclerosus

Dermal superficial collagen sclerosis Dense compaction and thickening of collagen fibers limited to the papillary and upper reticular dermis, which clinically translates as pearly whitish plaques that are atrophic to the touch. It is the characteristic histopathological finding of active lichen sclerosus and atrophicus.

Also: superficial dermal sclerosis · hyalinization of papillary collagen

Progressive diffuse cutaneous sclerosis Generalized, progressive and severe induration of the skin that affects the extremities, trunk and face, associated with a loss of dermal elasticity due to massive collagen fibrosis and adnex atrophy. It is the major dermatological manifestation of diffuse systemic sclerosis.

Also: diffuse skin induration · diffuse cutaneous systemic sclerosis

Active localized cutaneous sclerosis Initial inflammatory phase of skin induration characterized by erythematous or violaceous plaques that progressively become whitish, hard and firm due to collagen deposition. Clinically it presents a violet active edge known as "lilac ring".

Also: active morphea · active localized skin induration

Depressed skin slough Semi-solid necrotic tissue, whitish or yellowish in color and viscous consistency, which lines the bottom of a skin ulcer, preventing tissue repair. It represents a mixture of degraded collagen, fibrin, leukocytes and bacterial debris.

Also: ulcer slough · sloughed necrotic tissue

Eosinophilic spongiosis of initial pemphigoid Presence of intercellular edema in the epidermis accompanied by infiltration and selective exocytosis of eosinophilic granulocytes among keratinocytes. It is a key histopathological finding to suspect bullous pemphigoid in its non-bullous or urticarial phase.

Also: eosinophilic spongiosis · exocytosis of eosinophils in early eczema

Epidermal eosinophilic spongiosis Abnormal accumulation of intercellular fluid in the epidermis that separates keratinocytes, accompanied by migration and selective exocytosis of eosinophilic granulocytes. It is a histological marker suggestive of initial bullous pemphigoid or pitting dermatitis.

Also: spongiosis with eosinophils · eosinophilic intercellular edema

Benign focal spongiosis Discreet and transient intercellular edema limited to small groups of keratinocytes of the stratum spinosum, without forming macroscopic clinical vesicles. It is a very common reactive histopathological finding in mild subacute dermatitis or regressing eczema.

Also: focal spongiosis · mild intercellular epidermal edema

Focal cutaneous myxoid stroma Presence of loose connective tissue rich in acidic mucopolysaccharides and hyaluronate with a pale basophilic color in dermal histology, which alters normal collagen density. It is identified in benign tumors such as cutaneous myxoma or myxoid fibrokeratoma.

Also: focal myxoid stroma · dermal myxoid degeneration

Compulsive neurotic skin excoriation Superficial or deep dermoepidermal injury self-inflicted by the patient through repeated and obsessive scratching of the skin with their nails, often on minimal lesions or healthy skin. It presents clinically with bloody crusts and atrophic or hyperchromic scars.

Also: compulsive psychogenic excoriation · neurotic cutaneous scratching

Neurotic excoriation due to scratching Superficial traumatic injury compulsively self-induced by the patient through repeated scratching with the nails on healthy or previously itchy skin, which usually heals with hyperpigmentation. It is associated with obsessive-compulsive spectrum disorders and severe anxiety.

Also: psychogenic excoriation · compulsive lesional scratching

Traumatic erosive excoriation Linear or irregular continuity solution self-inflicted by vigorous scratching with the nails on itchy skin, which reaches the upper portion of the papillary dermis and causes pinpoint bleeding. It usually heals with residual post-inflammatory hyperpigmentation.

Also: excoriation due to dermoepidermal scratching · erosive scratching lesion

Linear traumatic excoriation Loss of linear or angular substance that compromises the epidermis and the upper portion of the papillary dermis, caused by acute external mechanical trauma. Clinically, it quickly becomes covered with blood crust and is common in accidents or attacks.

Also: linear scratching lesion · traumatic excoriation

Eosinophil exocytosis from contact dermatitis Presence of eosinophilic granulocytes scattered among the spongiotic keratinocytes of the epidermis, secondary to a type IV delayed hypersensitivity inflammatory reaction induced by topical allergens. It is accompanied by intense itching and vesiculation.

Also: intraepidermal contact eosinophils · exocytosis of contact eczema

Exocytosis of epidermal eosinophils Selective infiltration of eosinophilic granulocytes in the stratum spinosum of the epidermis, frequently associated with discrete intercellular edema. It is a histological sign highly suggestive of allergic reactions to medications, bites or initial pemphigoid.

Also: intraepidermal eosinophilia · eosinophilic exocytosis

Lymphoid epidermal exocytosis Active migration of mature lymphocytes towards the epidermal layer without evidence of spongiosis or significant intercellular edema, distributed among keratinocytes in a diffuse manner or in nests. It is characteristic of mycosis fungoides.

Also: lymphoid epidermotropism · lymphocyte exocytosis

Lymphoid epidermal exocytosis of mycosis fungoides Migration and active infiltration of atypical TCD4 lymphocytes from cerebriform nuclei towards the epidermis without causing edema or intercellular spongiosis around them, frequently organizing themselves into intraepidermal nests. It is characteristic of cutaneous T-cell lymphoma.

Also: epidermotropism of mycosis fungoides · exocytosis of atypical lymphocytes

Neutophilic epidermal exocytosis Selective migration of neutrophilic polymorphonuclear leukocytes into the interior of the epidermis in response to superficial inflammatory or infectious chemotactic stimuli. It is of great importance for the formation of pustules and intraepidermal microabscesses.

Also: neutrophil exocytosis · migration of neutrophils to epidermis

Dermal erythrocyte extravasation Abnormal exit of red blood cells from the lumen of the capillaries towards the connective stroma of the dermis, which clinically manifests as a purpuric lesion that does not clear up to vitro pressure. It is the elemental change of pigmentary purpuric dermatoses and vasculitis.

Also: extravascular erythrocytosis · dermal extravasated red blood cells

Superficial skin exulceration Loss of skin substance that compromises the entire epidermis and the most apical portion of the papillary dermis, preserving most of the dermal stroma. Unlike the true ulcer, it has a rapid healing potential with almost no persistent scarring.

Also: superficial dermal exulceration · superficial dermal erosion

Dense collagen fasciculation Massive thickening and narrow compaction of dermal collagen fibers that are arranged in a disorganized manner, reducing the capillary interstitial space of the dermis. It constitutes the pathological substrate that confers clinical rigidity to morphea plaques.

Also: compaction of collagen bundles · dense fasciculation of dermal collagen

Hyalinized collagen fasciculation Thickening of the dermal collagen bundles that acquire a homogeneous, shiny eosinophilic and acellular appearance due to severe chronic inflammatory processes or radiation. It noticeably alters skin elasticity and microcirculation.

Also: hyalinization of dermal collagen · you make hyaline collagens

Dermal stromal fibroplasia Reactive proliferation of fibroblasts accompanied by new thin-walled capillaries, which actively synthesize loose collagen in response to injury or local inflammation in the dermis. It constitutes the histological basis of granulation tissue and healing remodeling.

Also: stromal fibroplasia · connective stroma proliferation

Dermal perivascular fibroplasia Concentric proliferation of fibroblasts and reactive deposition of loose collagen around the small blood vessels of the papillary dermis, typical of severe chronic inflammatory processes or dysplastic nevi. Alters localized capillary compliance.

Also: perivascular concentric fibroplasia · dermal perivascular collagenization

Chronic draining cutaneous fistula Anomalous duct with an epithelialized tract that communicates a deep inflammatory cavity or an internal organ with the surface of the skin, actively draining purulent, serous or bloody material. Its resolution requires definitive treatment of the infectious or inflammatory focus of origin.

Also: cutaneous fistulous tract · suppurative cutaneous fistula

Commissural labial fissure Painful linear crack located selectively in the corner of the lips, of multifactorial origin associated with saliva maceration, nutritional deficiencies or Candida albicans infections. It causes marked pain when opening the mouth.

Also: angular cheilitis · lip corner crack

Labia commissural fissure of angular cheilitis Linear, erythematous and painful solution of continuity located in the angle or corner of the lips, favored by the accumulation of saliva, loss of vertical dimension or concomitant infection by Candida. It causes burning pain when gesturing or chewing.

Also: mouth · commissural angular cheilitis

Interdigital skin fissure Painful linear continuity solution located in the folds of the skin between the fingers, frequently associated with maceration due to humidity, extreme xerosis or dermatophytic infections such as athlete's foot. It represents an entry route for bacterial superinfections.

Also: interdigital crack · painful interdigital fissure

Perianal skin fissure Narrow, linear crack or tear that compromises the cutaneous-mucosal junction of the anal margin, extending through the epidermis to the upper dermis. Clinically, it presents with intense pain during defecation and bright red bleeding.

Also: anal fissure · perianal skin crack

Painful perianal skin fissure Painful linear tear of the perianal skin that extends through the epidermis to compromise the papillary dermis, caused by traumatic distension during defecation or local inflammatory processes. Clinically, it presents with persistent burning pain after evacuation and pinpoint bleeding.

Also: painful anal fissure · depressed perianal fissure

Plantar skin fissure of heel Painful linear crack or break that runs through the hyperkeratotic epidermis of the heel until it reaches the dermis, caused by the loss of elasticity due to extreme plantar xerosis combined with mechanical pressure. It causes marked pain when putting the foot down.

Also: plantar heel crack · fissure due to plantar xerosis

Painful plantar skin fissure Linear and deep continuity solution located in the hyperkeratotic support areas of the soles of the feet or heels, which extends through the papillary dermis causing intense pain when walking and occasional bleeding. It is very common in patients with severe plantar xerosis or keratodermas.

Also: painful plantar crack · heel crack

Deep suppurative folliculitis Bacterial infection of the hair follicle that extends beyond the infundibular portion towards the deep portions of the dermis, producing a perifollicular abscess with destruction of the pilosebaceous unit. Clinically, it presents with very painful erythematous nodules and a central pustule.

Also: deep folliculitis · deep follicular abscess

Superficial suppurative folliculitis Bacterial infection limited to the follicular infundibulum that manifests clinically as a small cupuliform and erythematous pustule, centered by a hair follicle, which heals without leaving a scar as it does not compromise the deep dermis. It is predominantly caused by Staphylococcus aureus.

Also: superficial folliculitis · Bockhart's follicular impetigo

Skin gallery of scabies Path excavated in the stratum corneum of the epidermis by the female mite Sarcoptes scabiei to deposit its eggs and feces. Clinically, it is seen as a raised, grayish or whitish line a few millimeters long, pathognomonic of scabies.

Also: acarine groove · scabies intraepidermal tunnel

Necrotizing cutaneous gas gangrene Rapidly progressive cutaneous and subcutaneous soft tissue infection caused by anaerobic gas-producing bacteria, clinically characterized by crepitus, skin necrosis, extreme pain and severe systemic repercussions. It represents a surgical medical emergency.

Also: gas gangrene of the skin · myonecrosis and gaseous skin necrosis

Chronic subcutaneous gum Nodule of firm consistency located in the subcutaneous cellular tissue that goes through a central softening phase, subsequently ulcerating and draining a rubbery or rubbery necrotic material. It is characteristic of tertiary syphilis, colliquative tuberculosis and deep mycoses.

Also: syphilitic gum · subcutaneous rubbery lesion

Dermal foreign body granuloma Nodular infiltrate composed of histiocytes, multinucleated foreign body-type giant cells and lymphocytes, organized around a non-digestible exogenous or endogenous material, such as sutures, silica, talc or extravasated keratin. Histologically the causal material is usually birefringent under polarized light.

Also: foreign body granuloma · granulomatous reaction due to foreign body

Dermal necrobiotic granuloma Histological inflammatory reaction characterized by palisades of histiocytes surrounding a center of degraded or necrobiotic collagen, devoid of normal cell nuclei. It is the pathognomonic finding of necrobiosis lipoidica and granuloma annulare.

Also: necrobiotic collagen granuloma · palisade granuloma

Necrobiotic palisade granuloma Histological tissue reaction characterized by histiocytes and giant cells that are arranged radially around a central area of necrotic or homogenized collagen. It is the defining morphological finding of granuloma annulare and cutaneous rheumatoid nodules.

Also: collagen palisade granuloma · granulomatous palisade necrobiosis

Hypergranulosis Abnormal increase in the thickness of the stratum granulosum of the epidermis, characterized by a greater density of keratohyalin granules in the cytoplasm of the upper keratinocytes. Clinically it results in areas of dense keratinization, observable in lichen planus.

Also: prominent stratum granulosum

Circumscribed hypergranulosis Localized pathological thickening of the stratum granulosum of the epidermis, which stains dark violet in conventional histology due to increased keratohyalin granules. It is a very important diagnostic histopathological finding in lichen planus.

Also: thickening of the granular layer · focal hypergranulosis

Wedge hypergranulosis Localized thickening of the stratum granulosum that adopts a triangular or wedge-shaped morphology, characteristically located under keratotic plugs or at the mouth of the follicular ducts. It is a morphological finding highly suggestive of lichen planus.

Also: wedge granulosis · triangular hypergranulosis

Lichen planus wedge hypergranulosis Circumscribed thickening of the stratum granulosum of the epidermis that adopts a triangular or wedge morphology, characteristically located at the follicular openings of lichen planus lesions. It is very useful for histopathological diagnosis.

Also: lichen planus wedge granulosis · triangular follicular hypergranulosis

Infundibular follicular hypergranulosis Localized thickening of the granular layer limited to the epithelial lining of the follicular infundibulum, often associated with keratosis and follicular obstruction. It is a common histological finding in early stages of acne and follicular lichen planus.

Also: follicular hypergranulosis · granular thickening of the hair infundibulum

Benign lobular sebaceous hyperplasia Benign proliferation of mature sebaceous lobes arranged around a common dilated follicular duct, located in the superficial dermis of the face. Clinically, it presents as yellowish papules, umbilicated in the center and with peripheral telangiectasias in mature patients.

Also: sebaceous hyperplasia of the face · senile sebaceous papule

Diffuse lobular sebaceous hyperplasia Generalized and diffuse increase in the number of mature sebaceous lobules that infiltrate in a disorderly manner the middle dermis of extensive facial areas, without grouping in a nodular manner around a common duct. It is described in rare variants of sebaceous hyperplasia or metabolic syndromes.

Also: diffuse sebaceous hyperplasia · benign diffuse sebaceous proliferation

Infundibular follicular hyperkeratosis Abnormal accumulation of keratin that obstructs and distends the infundibular portion of the pilosebaceous follicle, preventing normal sebaceous drainage. Clinically it manifests itself as follicular keratotic papules that are rough to the touch, called "goosebumps."

Also: follicular horny plug · infundibular follicular keratosis

Localized orthokeratotic hyperkeratosis Localized thickening of the stratum corneum that respects the anucleated cellular structure of mature keratinocytes, limited to specific areas subjected to microtrauma or localized mechanical friction. Clinically it manifests itself as calluses or helomas.

Also: orthokeratotic localized hyperkeratosis · anucleated circumscribed corneal thickening

Diffuse orthokeratotic hyperkeratosis Massive and uniformly distributed thickening of the epidermal stratum corneum that preserves the physiological anucleated cell morphology of the mature keratinocyte. It is characteristically observed in genodermatous processes such as ichthyosis vulgaris and in areas of repeated chronic friction.

Also: orthokeratotic hyperkeratosis · diffuse anucleate corneal thickening

Follicular orthokeratotic hyperkeratosis of keratosis pilaris Compact accumulation of keratin in the infundibular portion of the hair follicle that forms a spinous horny plug that obstructs the follicular ostium. Clinically, it produces small, rough, asymptomatic follicular papules in the extensor portion of the extremities.

Also: keratosis pilaris · horny plug of keratosis pilaris

Spinous follicular orthokeratotic hyperkeratosis Thickening of the stratum corneum that is confined to the follicular ostium, protruding from the surface of the skin in the form of fine keratotic spines that give it a rough feel. It is the microscopic translation of keratosis pilaris and pityriasis rubra pilaris.

Also: keratotic follicular spine · spinous horny plug

Diffuse parakeratotic hyperkeratosis Generalized presence of keratinocytes that retain their nuclei in a significantly thickened stratum corneum, which involves extensive body surfaces or confluent plaques. It indicates a global or severe disorder of epidermal differentiation, as occurs in psoriasiform erythroderma.

Also: diffuse parakeratosis · generalized parakeratotic hyperkeratosis

Focal parakeratotic hyperkeratosis Presence of flattened and dense cell nuclei within the thickened epidermal stratum corneum, arranged in patches or foci delimited on the epidermis. It indicates an accelerated and defective keratinization process, typical of subacute eczema and pityriasis rosea.

Also: focal parakeratosis · hyperkeratosis with retained nuclei

Hypogranulosis Decrease in thickness or complete absence of the stratum granulosum of the epidermis, which is usually histologically correlated with an accelerated keratinization process. It is a defining morphological characteristic of psoriasis plaques.

Also: reduction of the stratum granulosum · thinned granular layer

Segmental hypogranulosis Notable decrease or localized absence of the stratum granulosum of the epidermis, frequently associated with supraadjacent parakeratotic hyperkeratosis. This phenomenon reflects accelerated transit of keratinocytes and is the classic histopathological finding of psoriasis.

Also: thinning of the granular layer · focal absence of stratum granulosum

Cutaneous intracytoplasmic viral inclusions Dense accumulations of proteins and viral particles in the cytoplasm of the keratinocytes of the epidermis, which appear as large eosinophilic or homogeneous structures. They are typical of molluscum contagiosum, where they are known as Henderson-Paterson bodies.

Also: intracytoplasmic inclusion bodies · mollusk bodies

Epidermal intranuclear viral inclusions Abnormal structures located in the nucleus of keratinocytes that move the chromatin towards the nuclear periphery, acquiring a ground glass appearance. They are pathognomonic of infections by the Herpesviridae family.

Also: intranuclear inclusion bodies · cores in viral frosted glass

Dermal pigment incontinence Loss of melanin by the keratinocytes of the basal stratum of the epidermis to the papillary dermis, where it is phagocytosed by tissue macrophages called melanophages. It is an indirect histological marker of previous damage to the epidermal basal layer.

Also: melanin incontinence · dermal melanin deposit

Melanocytic pigment incontinence Pathological loss of melanin granules synthesized in the epidermis that fall and are deposited freely or phagocytosed in the upper dermis, secondary to the destruction of the melanocytes of the basal layer. It produces a clinically persistent grayish or bluish discoloration of the skin.

Also: dermal melanin incontinence · pigment drop to the dermis

Granulomatous dermal infiltrate of lepromatous leprosy Diffuse infiltration of the reticular dermis by modified histiocytes with abundant vacuolated cytoplasm, known as Virchow cells, which contain multiple Mycobacterium leprae bacilli. It characteristically respects a thin band of subepidermal dermis or band of Unna.

Also: Virchow infiltrator · diffuse granuloma of lepromatous leprosy

Diffuse granulomatous dermal infiltrate Disseminated presence of mature histiocytes that occupy large areas of the reticular dermis without grouping into defined nests, altering the collagen stroma. It is typical of the stable phases of lepromatous leprosy and some systemic mycoses.

Also: diffuse interstitial granuloma

Massive dermal eosinophilic infiltrate Dense accumulation of eosinophilic granulocytes in the dermal stroma, often with degranulation and formation of "flame figures" on the collagen fibers. It is associated with reactions to insect bites, Wells syndrome and pharmacodermias.

Also: dermal eosinophil infiltrate · dermal tissue eosinophilia

Diffuse granulomatous histiocytic infiltrate Generalized dispersion of histiocytes and epithelioid macrophages in the thickness of the dermis without a clear nodular or circumscribed organization, which alters the normal collagen architecture. It is characteristic of interstitial granuloma annulare and the early inflammatory phases of lepromatous leprosy.

Also: diffuse granulomatous infiltrate · diffuse histiocytic interstitial granuloma

Focal granulomatous histiocytic infiltrate Organized accumulation of modified macrophages, also called epithelioid cells, accompanied by giant cells and lymphocytes, forming small nodules delimited in the dermis. It is observed in intracellular infectious processes such as tuberculosis or mycosis and in sarcoidosis.

Also: epitheloid cell granuloma · circumscribed granulomatous infiltrate

Perivascular dermal lymphoid infiltrate Accumulation of lymphocytes arranged in a sleeve selectively around the blood vessels of the superficial and middle dermis, without compromising the vascular endothelium. It constitutes the pathological substrate of urticarial reactions, pharmacological exanthems and reactive dermatitis.

Also: perivascular inflammatory infiltrate · perivascular lymphocyte cuffs

Superficial dermal lymphoid infiltrate Presence of an abnormal accumulation of mature lymphocytes in the papillary and upper perivascular dermis, associated with capillary dilation. It is the common immunological and inflammatory response that underlies most acute and subacute inflammatory dermatoses.

Also: superficial lymphoid inflammatory infiltrate · superficial lymphocyte cuffs

Superficial dermal perivascular lymphoid infiltrate Reactive accumulation of mature lymphocytes arranged around the blood vessels of the superficial vascular plexus of the dermis, associated with capillary dilation. It constitutes the pathological substrate of the vast majority of acute inflammatory dermatoses.

Also: superficial perivascular inflammatory infiltrate · superficial lymphoid cuff

Dense lichenoid infiltrate Massive accumulation of lymphocytes and macrophages that adopt a continuous band arrangement in the papillary dermis, closely linked to the dermoepidermal junction, which causes the destruction of the stratum basale. It is characteristic of lichen planus and lichenoid drug eruption.

Also: infiltrated in lichenoid band · band lymphoid inflammatory infiltrate

Dense band lichenoid infiltrate Continuous and dense accumulation of mature lymphocytes and histiocytes that are arranged horizontally in the papillary dermis immediately below the epidermis, eroding the dermoepidermal junction. It is the defining pathological sign of lichenoid processes such as lichen planus.

Also: band of lichenoid infiltrate · infiltrated dermoepidermal band of lichen planus

Dense lichenoid infiltrate in band of lichen planus Continuous horizontal band of inflammatory infiltrate composed exclusively of T lymphocytes and macrophages located in the papillary dermis, which selectively and confluently attacks the epidermal basal layer. It is the defining pathognomonic finding of lichen planus.

Also: band of lichen planus histology · lymphoid infiltrate in the dermal-epidermal junction band

Dense lichenoid infiltrate in horizontal band Massive accumulation of mature lymphocytes and histiocytes that are arranged confluently in a horizontal band in the upper dermis, erasing the dermoepidermal junction and destroying basal keratinocytes. It is the definitive diagnostic pathological finding of lichen planus.

Also: lymphoid infiltrate band · dermoepidermal infiltrate of lichen planus

Lichenoid infiltrate in band of papillary dermis Dense inflammatory accumulation of mature lymphocytes and histiocytes that are arranged confluently in the papillary dermis, horizontally erasing the dermoepidermal junction and destroying basal keratinocytes. It is the defining morphological finding of lichen planus.

Also: lichenoid inflammatory band · infiltrated dermoepidermal band of lichen planus

Dermal interstitial neutrophilic infiltrate Diffuse presence of neutrophilic polymorphonuclear leukocytes dispersed among the collagen fibers of the dermis, without a clear perivascular predilection. It is the defining morphological finding of neutrophilic dermatoses such as Sweet syndrome.

Also: diffuse dermal neutrophilic infiltrate · interstitial neutrophils in dermis

Sweet dermal interstitial neutrophilic infiltrate Massive and diffuse presence of mature polymorphonuclear neutrophils located in the upper dermal interstitium, accompanied by marked papillary edema and discrete leukocytoclasia, without evidence of true vasculitis. It is the defining finding of acute febrile neutrophilic dermatosis.

Also: neutrophilic Sweet infiltrator · Sweet's diffuse dermal neutrophils

Solid primary elementary lesion Skin anomaly that develops on previously healthy skin without being preceded by another skin alteration, characterized histologically by infiltration or proliferation of cells in the epidermis or dermis. It includes specific subtypes of complex papules, nodules and infiltrated plaques.

Also: primary solid skin lesion · primary non-liquid skin change

Elementary secondary destructive injury Dermatological alteration that derives from the spontaneous evolution, regression, trauma or superinfection of a previous elemental lesion, characterized by the loss of skin layers or abnormal residual deposits. It includes ulcers, fissures, excoriations, scabs and complex scars.

Also: secondary destructive cutaneous lesion · secondary skin alteration with tissue loss

Interdigital scabies line Elevated and sinuous linear path located in the folds of the skin between the fingers of the hands, corresponding to the intraepidermal gallery excavated by the scabies mite. It is one of the topographic locations with the highest clinical yield for the diagnosis of scabies.

Also: interdigital acarine groove · scabies tunnel in interdigital folds

Raised scabies line Clinical manifestation consisting of a filiform and sinuous elevation of a few millimeters in length on the skin surface, which ends in a small papule or pearly vesicle. It represents the macroscopic translation of the gallery excavated by the mite.

Also: elevated acarine path · scabiotic excavation line

Atypical epidermal intraepithelial lymphocyte Lymphoid cell with abnormal nuclear morphology, irregular or cerebriform contour, which migrates towards the epidermal layer without provoking a spongiotic response around it. It is of great importance for the histopathological diagnosis of cutaneous T-cell lymphoma.

Also: intraepidermal cerebriform lymphocyte · epidermotropism of atypical lymphoid cells

Reactive epidermal lymphocytosis Presence of lymphocytes with a mature and non-atypical appearance within the epidermis, accompanying benign inflammatory processes with spongiosis or interface dermatitis. It is differentiated from neoplastic epidermotropism by the coexistence of marked intercellular edema.

Also: benign lymphoid exocytosis · reactive intraepidermal lymphocytes

Reactive circumscribed lichenification Thickened, rough skin plaque with marked accentuation of the normal grid lines of the skin, caused by chronic and repeated rubbing or scratching on a specific area of the skin. It is the defining lesion of lichen simplex chronicus or neurodermatitis.

Also: localized lichen simplex chronicus · reactive thickening of the skin due to friction

Necrotizing purpuric reticular liver Skin vascular pattern characterized by a persistent network or mesh of erythematous-purple color that does not clear when pressed, accompanied by small necrosis or ulcerations at the points of vascular confluence. Indicates severe capillary or arteriolytic occlusion due to vasculopathies or thrombosis.

Also: livedo reticularis purpurica · necrotizing reticular livedo

Active erythematous erythematous macule Bright red flat skin spot due to active arterial vasodilation and increased local blood flow, which clinically is usually associated with a discrete increase in local skin temperature. It is typical of acute inflammatory or early infectious processes such as cellulitis.

Also: active erythematous macula · macular active erythema

Transient congestive erythematous macule Flat and circumscribed skin area of reddish color due to capillary vasodilation located in the upper dermis, which temporarily pales under digital pressure or vitro pressure. It is commonly observed in emotional flushing or initial viral exanthems.

Also: transient erythematous macule · congestive macular erythema

Passive congestive erythematous macule Flat spot of violet-red or bluish color due to venous stasis or delay in capillary circulatory return of the dermis, which shows a low local temperature to the touch. It is classically associated with states of acrocyanosis, chilblains or venous ischemia.

Also: passive macular erythema · passive cyanotic macula

Persistent purplish erythematous macule Reddish-violet stain that combines an inflammatory component of vasodilation with extravasation of red blood cells in the dermal stroma, which is why it only partially clears up to vitropressure. It is a common finding in the initial stages of cutaneous vasculitis and severe insect bites.

Also: erythematous-violaceous macule · inflammatory purpuric spot

Total achromic pigmentary macule Flat, well-defined lesion characterized by the absolute loss of melanic pigment in the epidermis due to the functional absence or total destruction of melanocytes. It is the basic characteristic and diagnostic lesion of vitiligo.

Also: depigmented macule · complete achromic stain

Melanic hyperchromic pigmentary macule Flat, circumscribed area of skin characterized by a darkening of its usual color due to a localized increase in the synthesis or deposition of melanin in the epidermis or dermis. It is typically exemplified by melasma, mature ephelides, and café au lait spots.

Also: hyperpigmented macule · melanic hyperchromic spot

Focal hypochromic pigmentary macule Flat skin spot characterized by a lighter color than the healthy surrounding skin, caused by the quantitative decrease in the concentration of melanin in the epidermis. It is commonly seen in pityriasis alba or post-inflammatory hypopigmentation.

Also: hypopigmented macule · light epidermal spot

Purpuric macule of linear vixex Flat purpuric lesion that adopts an elongated or linear morphology, caused by the extravasation of red blood cells in areas subjected to traction forces, violent scratching or linear skin trauma. It is commonly seen in recent skin stretch marks or after blunt trauma.

Also: hemorrhagic vibix · linear purpuric striae

Extensive ecchymotic purpuric macule Large violet or dark flat plaque or spot, produced by massive extravasation of blood in the deep subcutaneous or dermal tissue. As the days go by, it experiences chromatic changes, turning from violet to green and yellow due to the degradation of hemoglobin.

Also: hemorrhagic ecchymosis · subcutaneous flat hematoma

Petechial hemorrhagic purpuric macule Small purpuric spot with a dotted and rounded shape, one to three millimeters in diameter, caused by the localized extravasation of red blood cells in the papillary dermis that does not disappear under vitro pressure. Its presence usually indicates capillary fragility or thrombocytopenia.

Also: hemorrhagic petechia · petechial spot

Charged dermal melanophage Macrophage located in the papillary or upper reticular dermis that has phagocytosed melanin granules released by damaged keratinocytes. Its presence in the biopsy is of great help to verify the previous existence of pigment incontinence.

Also: histiocyte loaded with melanin · melanophage of the dermis

Laden papillary dermal melanophage Histiocyte located in the dermal papillae that presents a cytoplasm full of phagocytosed melanin granules from the damaged basal layer, brown or black in routine staining. Its focal grouping clinically translates into long-lasting post-inflammatory hyperpigmented macules.

Also: papillary melanophagus · histiocyte loaded with melanin pigment in the dermal papilla

Intraepidermal Munro microabscess Small intraepidermal cluster of necrotic neutrophilic polymorphonuclear leukocytes located selectively within the parakeratotic stratum corneum. It is the histopathological diagnostic finding par excellence of psoriasis vulgaris.

Also: Munro microabscess · Munro's neutrophilic nest

Intraepidermal Pautrier microabscess Circumscribed grouping of T helper lymphocytes with atypical and cerebriform morphology located in the thickness of the epidermis, surrounded by a clear halo. It constitutes the defining pathognomonic finding of mycosis fungoides.

Also: Pautrier microabscess · Pautrier lymphoid nest

Neutophilic microabscess of dermal papilla Focal accumulation of neutrophils located selectively at the apex of the dermal papillae, associated with necrosis of the supraadjacent basal keratinocytes. It is the early morphological finding of dermatitis herpetiformis.

Also: neutrophilic papillary microabscess · dermal papilla microabscess

Diffuse dermal interstitial mucin Pathological and diffuse deposition of acidic mucopolysaccharides and hyaluronate in the interstitial spaces between the collagen bundles of the reticular dermis, which displaces the normal fibrillar structures. It is characteristic of pretibial myxedema and follicular mucinosis.

Also: interstitial dermal mucin · mucin accumulation in the dermis

Focal cutaneous mucinosis Presence of a solitary nodule or circumscribed plaque characterized by an abundant deposit of mucin in the upper dermis that almost completely replaces normal collagen, with the presence of stellate fibroblasts. Clinically, it presents as an asymptomatic lesion of soft consistency.

Also: focal mucinosis · circumscribed mucin deposit

Acute total epidermal necrosis Massive cell death and confluent detachment of the entire thickness of the epidermis due to generalized keratinocyte apoptosis mediated by cytotoxic T lymphocytes. It is the pathological basis of Stevens-Johnson syndrome and toxic epidermal necrolysis.

Also: confluent necrosis of the epidermis · massive epidermal necrolysis

Lobular fatty necrosis with crystals Death of adipocytes within the fat lobes that histologically shows lipid crystals arranged in a needle in the cytoplasm of necrotic fat cells, surrounded by a histiocytic reaction. It is pathognomonic of subcutaneous fat necrosis of the newborn.

Also: adipocyte necrosis with crystals · neonatal steatonecrosis with radial clefts

Lobular fatty necrosis of pancreatic panniculitis Enzymatic necrosis of adipocytes located in the lobes of the subcutaneous tissue induced by the systemic release of pancreatic lipases, characterized by fat cells with thickened and hyalinized membranes known as "ghost cells". It presents clinically with fluctuating erythematous-violet nodules.

Also: pancreatic steatonecrosis · lobular pancreatic panniculitis

Lobular subcutaneous fat necrosis Cell death of adipocytes that mainly affects the center of the fatty lobes of the subcutaneous cellular tissue, accompanied by inflammatory infiltrate and subsequent calcareous deposition or fibrosis. It is seen in lobular panniculitis and fat necrosis of the newborn.

Also: lobular adipocyte necrosis · lobular steatonecrosis

Compound nevus Melanocytic proliferation that simultaneously combines nests of nevic cells in the dermoepidermal junction and nests that infiltrate the underlying dermis. Clinically, it usually manifests as a raised papule with a surrounding hyperpigmented macular halo.

Also: compound nevus · compound dermoepidermal nevus

Benign cellular Spitz nevus Melanocytic proliferation of epithelioid and fusiform cells of uniform appearance that infiltrate the dermoepidermal junction and the papillary dermis, showing cellular maturation in depth. Histologically it presents Kamino bodies and requires rigorous differentiation from melanoma.

Also: Spitz nevus · benign Spitz tumor

Atypical active dysplastic nevus Melanocytic proliferation with cytological atypia and architectural disorganization showing nests with interpapillary bridges and marked perivascular fibroplasia in the papillary dermis. It is considered a precursor and important risk marker for the development of malignant melanoma.

Also: dysplastic nevus · active atypical nevus

Epidermal junctional melanocytic nevus Benign proliferation of melanocytes organized in thecae or nests that are located exclusively in the dermoepidermal junction, without penetrating the dermis. Clinically, it appears as a brown or black macule, well-defined and symmetrical.

Also: union nevus · intraepidermal melanocytic nevus

Intradermal dermal melanocytic nevus Benign proliferation of melanocytes organized in nests that are located entirely within the dermal stroma, with the binding component having disappeared. Clinically it usually presents as a flesh-colored or light brown domed papule or nodule.

Also: intradermal nevus · pure dermal nevus

Metabolic depot nodule Raised and firm formation caused by the dermal or subcutaneous intraparenchymal accumulation of abnormal exogenous or endogenous metabolic substances, such as urate crystals, lipids or amyloid proteins. It is associated with tophaceous gout, nodular xanthomas or nodular amyloidosis.

Also: tophus or metabolic nodule · deposit node

Painful deep erythematous nodule Raised, solid lesion, located deep dermis or subcutaneously, larger than one centimeter and characterized by marked painful sensitivity to physical pressure. Clinically it represents the classic manifestation of erythema nodosum or active panniculitis.

Also: deep inflammatory nodule · painful subcutaneous nodule

Necrotising lobular panniculitis Acute inflammation of the subcutaneous cellular tissue located predominantly inside the fat lobes, accompanied by cellular necrosis of adipocytes and inflammatory infiltrate of neutrophils, histiocytes and foam cells. It is characteristic of erythema nodosum leprosum and pancreatic panniculitis.

Also: fatty lobular inflammation · lobular panniculitis with necrosis

Chronic septal panniculitis Inflammatory process selectively located in the connective tissue septa or septa that separate the fat lobes from the subcutaneous cellular tissue, causing fibrous thickening thereof. Histologically, it occurs without lobular fat necrosis and is the key to the diagnosis of erythema nodosum.

Also: inflammation of fatty septa · septal panniculitis without vasculitis

Cutaneous epidermal papillomatosis Histological elevation characterized by the projection of the dermal papillae above the normal level of the skin, which causes an undulating, warty or digitiform appearance of the supraadjacent epidermis. It is seen very clearly in acanthomas and common warts.

Also: epidermal papillomatosis · cutaneous papillary projections

Hard keratotic papule Solid elevation of the skin less than one centimeter in size that is characterized by a rough, hard, horny covering that does not easily detach from the lesional surface. It is the defining lesion of common warts and hyperkeratotic actinic keratoses.

Also: keratotic papule · elevated keratotic lesion

Hard keratotic papule of actinic keratosis Solid elevation of the skin less than a centimeter in size covered with a rough, hard and very adherent hyperkeratotic scale, caused by the atypical proliferation of basal keratinocytes induced by ultraviolet radiation. It is considered a precursor lesion of squamous cell carcinoma.

Also: senile keratosis papule · raised actinic keratosis lesion

Hard keratotic papule of keratosis follicularis of Darier Small solid elevation less than one centimeter, with a rough, dry, rough surface and brownish color, located in seborrheic areas of the skin due to a genetic defect in epidermal cell adhesion. It is grouped into warty plaques with a foul odor.

Also: Darier papule · Darier follicular keratosis papule

Hard keratotic papule of verruca vulgaris Solid elevation less than a centimeter in size with a rough and rough surface, characterized by marked acanthosis, papillomatosis and orthokeratotic hyperkeratosis induced by the human papillomavirus. It has tiny black dots that correspond to thrombosed capillaries.

Also: warty papule · elevated verruca vulgaris lesion

Rough follicular keratotic papule Solid elevation less than a centimeter in size centered on a hair follicle, clinically characterized by a hard, prickly keratotic plug that protrudes from the ostium, giving a grater-like feel to the skin. It is the basic diagnostic lesion of keratosis pilaris.

Also: keratosis pilaris papule · rough keratotic follicular lesion

Viral umbilicate papule Small solid skin elevation that presents a navel-shaped central depression, characteristic of molluscum contagiosum and some systemic opportunistic fungal infections such as cutaneous cryptococcosis. Its center usually contains keratin plugs or viral debris.

Also: papule with central depression · umbilicate papule

Destructive nodular perifolliculitis Dense granulomatous and suppurative inflammation located around the hair follicle, frequently caused by the rupture of the follicular epithelium and the release of keratin and sebum into the surrounding dermis. It clinically presents with painful nodules and can lead to depressed scars.

Also: granulomatous perifollicular inflammation · nodular perifolliculitis

Tumor Scaly Keratin Pearl Spheroidal histological structure composed of concentric sheets of compact and acidophilic keratin located in the thickness of the dermis, caused by the keratinization of differentiated tumor cells. It is a major criterion for diagnosing well-differentiated squamous cell carcinoma.

Also: horny pearl · carcinoma keratin pearl

Placa eritematoedematosa persistente Raised lesion of large surface area characterized by a soft consistency, pink or reddish color and marked edema of the stroma of the upper dermis that deforms the surface of the skin. Unlike the classic hives of urticaria, this plaque persists motionless in the same place for more than twenty-four hours.

Also: urticaria-vasculitis plaque · persistent edematous plaque

Adherent erythematous squamous plaque Flat skin elevation that occupies a medium to large surface, clinically characterized by an inflammatory erythematous base covered with whitish and very adherent scales. It is the elementary lesion characteristic of plaque psoriasis vulgaris and severe seborrheic dermatitis.

Also: plate with scales · erythematous squamous plaque of psoriasis

Erythematous squamous plaque of nummular eczema Flat raised lesion of circular or oval shape, with well-defined edges and erythematous color, covered with fine scales and dotted scabs due to previous vesiculation. Clinically it simulates a coin and presents with very intense itching.

Also: discoid plaque of eczema · erythematosquamous nummular lesion

Erythematous scaly plaque of nummular eczema of the legs Flat, circular, erythematous and pruritic raised lesion frequently located on the lower extremities of adult patients with severe skin xerosis, characterized by initial exudation and subsequent dry peeling.

Also: discoid eczema of the legs · numular eczema erythematosquamous plaque

Erythematous squamous plaque of psoriasis vulgaris Flat raised lesion of medium to large size, with well-defined edges and bright red color, covered with abundant stratified silvery-white scales. It is a consequence of extremely accelerated epidermal cell turnover.

Also: psoriasis plaque · erythematosquamous psoriasiform plaque

Micaceous erythematosquamous plaque Flat raised lesion characterized by a bright red color covered with pearly white scales that break off in translucent sheets that look similar to mica. It represents the macroscopic translation of parakeratotic hyperkeratosis and psoriasiform acanthosis of plaque psoriasis.

Also: micaceous psoriasis plaque · silver scaly plaque of psoriasis

Dermal neoplastic infiltrative plaque Flat and firm skin elevation that originates from the presence of a continuous neoplastic cellular infiltrate in the thickness of the dermis, modifying the skin consistency that becomes indurated and with well-defined edges. It is characteristic of cutaneous lymphoma or nodular sarcoidosis.

Also: neoplastic infiltrated plaque · dermal plaque of tumor cells

Raised lichenoid plate Flat raised lesion of erythematous-violet color, characterized by a shiny surface and whitish lines known as Wickham's striae, secondary to a chronic inflammatory band infiltrate in the papillary dermis. It is classically described as the elementary lesion of lichen planus.

Also: lichen planus plaque · violaceous lichenoid plaque

Atrophic cutaneous poikiloderma Clinical combination of epidermal skin atrophy, fine superficial telangiectasias and mottled areas of hyperpigmentation and hypopigmentation that give the skin a reticulated and aged appearance. It is associated with chronic actinic damage, mycosis fungoides and congenital syndromes.

Also: poikiloderma · atrophic mottled skin with telangiectasias

Dermal neutrophil nuclear dust Presence of small spheroidal basophilic fragments resulting from nuclear fragmentation or karyorrhexis of neutrophils that actively infiltrate the dermal stroma. It is a highly sensitive histological indicator of active vasculitis or severe neutrophilic inflammation.

Also: neutrophilic nuclear dust · dermal leukocytoclasia

Nodular dermal fibroblastic proliferation Focal multiplication of spindle-shaped fibroblasts accompanied by dense collagen deposition in the reticular dermis, which clinically translates as an asymptomatic and firm brown nodular lesion with a positive clamp sign. It is the defining finding of dermatofibroma or benign fibrous histiocytoma.

Also: dermal fibroblastic proliferation · dermatofibroma nodule

Kogoj spongiform pustule Histological grouping of neutrophilic polymorphonuclear leukocytes located inside the degenerated spongiotic keratinocytes of the upper spinous stratum of the epidermis, giving it a network or honeycomb appearance. It is extremely characteristic of pustular psoriasis.

Also: Kogoj spongiform microabscess · Kogoj pustule

Infectious follicular pustule Circumscribed collection of pus located selectively inside the ostium or duct of the hair follicle, typically centered by a visible hair on the skin surface. It is usually of bacterial origin due to Staphylococcus aureus or fungal due to Malassezia.

Also: follicular pustule · superficial pustular folliculitis

Aseptic non-follicular pustule Elevated and cavitated lesion with purulent content that is located independently of the hair follicles, characterized by the absence of viable pathogens inside. It is typical of pustular psoriasis and some pustular drug eruptions.

Also: non-follicular pustule · diffuse aseptic pustule

Aseptic subcorneal non-follicular pustule Collection of pus located immediately below the stratum corneum, independent of the pilosebaceous apparatus and devoid of microorganisms inside. It is the defining lesion of Sneddon-Wilkinson subcorneal pustular dermatosis.

Also: aseptic subcorneal pustule · Pustular cavity of Sneddon-Wilkinson

Sneddon-Wilkinson subcorneal non-follicular pustule Collection of sterile purulent contents accumulated directly beneath the stratum corneum of the epidermis independently of the hair follicles, composed predominantly of mature neutrophils. It is characteristic of subcorneal pustular dermatosis.

Also: Sneddon-Wilkinson pustule · aseptic subcorneal pustule of Sneddon

Liquefied basal apoptotic keratinocyte Individual basal epithelial cell undergoing programmed cell death with cytoplasmic retraction and fragmentation of its nucleus due to interface dermatitis, floating in a microcystic junctional space. It is the initial morphological element for the formation of dermoepidermal clefts.

Also: liquefied basal necrotic keratinocyte · liquefactive union Civatte body

Liquefied basal necrotic keratinocyte from interface dermatitis Basal cell that undergoes programmed cell death due to the immunological aggression of cytotoxic T lymphocytes, visualized as an eosinophilic globule without a nucleus surrounded by liquid vacuoles at the dermoepidermal junction. It is the elemental change of interface dermatitis.

Also: liquefactive basal Civatte body · necrotic keratinocyte of dermal-epidermal junction

Liquefied basal necrotic interface keratinocyte Epidermal cell of the basal layer that undergoes apoptosis or lysis due to immunological damage mediated by T lymphocytes, observed histologically as a reduced, eosinophilic structure with perinuclear vacuolization. It is the initial step for the formation of junctional microvesicles.

Also: interface basal Civatte body · liquefactive necrotic keratinocyte

Favre-Racouchot follicular keratoelastoidosis Degenerative skin disorder characterized by marked solar elastosis of the facial dermis associated with distension of the follicular ducts by keratin and sebum, forming giant, painless comedones. It typically occurs in elderly men chronically exposed to the sun.

Also: giant comedones with solar elastosis

Follicular keratoelastoidosis of the face Degenerative pathology of the collagen tissue and the perofollicular elastic fibers of the facial skin, associated with a marked hyperkeratosis of the follicular ostia in patients with extreme sun exposure. Clinically, it produces firm, grouped yellowish papules with giant comedones.

Also: Favre-Racouchot disease · senile follicular elastosis with cysts

Favre-Racouchot follicular keratoelastoidosis of the temples Variety of actinic degeneration characterized by the concentric accumulation of amorphous and basophilic elastic fibers around the hair follicles of the temple and periocular region, associated with keratotic follicular dilations. It is common in elderly people with advanced photoaging.

Also: Favre-Racouchot follicular elastosis · comedones and cysts due to solar elastosis of the temples

Epidermal acanthotic seborrheic keratosis Benign epithelial proliferation characterized by hyperplasia of basaloid cells of the epidermis containing multiple keratin cysts and corneal inclusion pseudocysts, sparing the basement membrane. Clinically, it presents as a pigmented plaque with a greasy appearance and a warty, glued-looking surface.

Also: acanthotic seborrheic keratosis · classic seborrheic keratosis

Infiltrating clonal seborrheic keratosis Histological variant characterized by the presence of circumscribed nests of basaloid epithelial cells with a uniform and rounded appearance located within the thickness of the proliferated epidermis. It should not be confused histologically with intraepidermal basal cell carcinoma or Bowen's disease.

Also: clonal seborrheic keratosis · clonal keratosis nests

Papillary hyperkeratotic seborrheic keratosis Histological variant of seborrheic keratosis characterized by marked hyperkeratosis and "church needle-shaped" papillomatosis with little epidermal acanthosis. It manifests clinically as dry, rough and very raised plaques with a keratotic appearance.

Also: hyperkeratotic seborrheic keratosis · seborrheic papillary keratosis

Fine reticulated seborrheic keratosis Variant of seborrheic keratosis characterized histologically by thin, branching cords of basal epithelial cells that originate from the epidermis and penetrate uniformly into the papillary dermis, frequently pigmented. It is usually associated clinically with old solar lentigines.

Also: reticulated seborrheic keratosis · pigmented reticular keratosis

Subepidermal keratotic milium cyst Small superficial cystic epidermal cavity one to two millimeters in diameter, filled with compact laminated keratin and located in the papillary dermis. It presents clinically as millimetric whitish papules of firm consistency on the face or after burns.

Also: milium cyst · subepidermal keratin milium

Superficial keratotic milium cyst Small subepidermal cyst, one to two millimeters in diameter, bright whitish or yellowish in color and firm in consistency, filled with compacted keratin and located in the upper dermis. It is very common on the face of newborns and in areas of scars.

Also: superficial milium · keratotic milium papule

Superficial keratotic milium cyst of the face Small sub-epidermal epidermal cyst located periocularly or malar, one to two millimeters in diameter, pearly white in color and firm in consistency, containing compacted laminated keratin. It is very common spontaneously or secondary to local trauma.

Also: milium of face · periocular superficial milium cyst

Traumatic epidermal inclusion cyst Benign cavity located in the dermis caused by the traumatic implantation of epidermis fragments in the dermal connective stroma, lined by stratified squamous epithelium producing compact keratin. Histologically it lacks a pore or natural follicular communication.

Also: epidermal inclusion cyst · traumatic keratin cyst

Trichilematic pilar cyst of the scalp Cavitated lesion located predominantly in the dermis of the scalp, covered by an epithelium that undergoes abrupt and homogeneous keratinization without forming stratum granulosum. Clinically it presents as a firm and mobile cupuliform nodule.

Also: pilar cyst · trichilemmal cyst of the scalp

Familial pilar trichilematic cyst Cavitated lesion of hereditary origin located in the dermal connective tissue of the scalp, whose lining epithelium undergoes keratinization without passing through the stratum granulosum, filling the lumen with compact and calcified keratin.

Also: familial pillar cyst · hereditary trichilemmal cyst of the scalp

Perivascular dermal siderosis Intratissue dermal accumulation of golden brown hemosiderin granules located inside macrophages and along collagen fibers around blood vessels, secondary to repeated extravasations of red blood cells. It is a typical finding of venous stasis dermatitis.

Also: hemosiderin deposition in the dermis · cutaneous siderosis due to stasis

Follicle Phantom Cell Shadow Acellular keratinocytic rest that preserves the silhouette and limits of its plasma membrane intact but has completely lost the nucleus, staining a bright eosinophilic color. This type of cell is the morphological marker of pilomatricoma.

Also: pilomatricoma shadow cell · follicular mummified keratinocyte

Qualified follicular phantom cell shadow Cellular remains of dead follicular keratinocytes that retain the shape of their cell membranes without a nucleus, which undergo a progressive process of calcification or amorphous mineral deposit in the dermis. It is a characteristic histological change in old pilomatricoma lesions.

Also: calcified ghost cell · calcified shadow cell

Acarine groove of scabies Microscopic or macroscopic path excavated in the epidermal stratum corneum by the Sarcoptes scabiei mite to complete its reproductive cycle, clinically visualized as a pearly grayish linear elevation. It is preferably located in the interdigital spaces and wrists.

Also: scabiotic groove · scabies tunnel

Dense follicular horny plug Compact and hyperkeratotic accumulation of dense keratin that occludes the lumen of the follicular infundibulum and sweat ducts, producing keratotic follicular papules that are hard to the touch. It is very characteristic of lichen sclerosus, discoid lupus erythematosus and follicular keratosis.

Also: follicular corneal plugging · follicular keratin plug

Telangiectasia in spider veins Small cutaneous arteriolar dilation characterized by a raised and reddish central point from which thin radiating capillaries originate that simulate the legs of a spider, which completely pales when pressure is applied to its center. It is associated with states of hyperestrogenism, liver disease and pregnancy.

Also: spider vein · stellar angioma

Dermal intraluminal fibrin thrombus Partial or total vascular occlusion inside the capillaries of the papillary or reticular dermis by organized deposits of acellular fibrin, which triggers localized skin ischemia. It is a direct histological indicator of coagulopathies, occlusive vasculopathies or necrotizing vasculitis.

Also: dermal vascular thrombus · fibrin capillary occlusion

Painful ischemic arterial ulcer Loss of skin substance with clear edges, excavated or "punched out" appearance, located on bony prominences of the lower extremities and due to severely decreased arterial blood perfusion. Clinically it is extremely painful and the pain worsens with elevation of the limb.

Also: ischemic ulcer · arterial foot ulcer

Painful ischemic arterial foot ulcer Loss of excavated skin substance with "punched out" edges and a necrotic background, located in the distal bony prominences of the lower extremities due to a severe arterial circulatory deficit. It causes intense pain that worsens with elevation of the leg.

Also: ischemic foot ulcer · painful arterial ulcer of extremities

Plantar poorly perforating neuropathic ulcer Deep skin continuity solution with a torpid and chronic evolution located in the areas of greatest plantar pressure in diabetic patients or patients with loss of sensitivity, with a characteristic hyperkeratotic edge and a painless background. It can be complicated by underlying osteomyelitis.

Also: plantar perforating bad · painless hyperkeratotic plantar ulcer

Plantar neuropathic ulcer with bad perforation Loss of skin substance of chronic evolution and painless background with thickened hyperkeratotic edges, located selectively in the support points of the foot subjected to repeated mechanical friction. It originates as a consequence of the loss of proprioceptive sensitivity.

Also: plantar neurotrophic heel ulcer

Plantar neuropathic ulcer of leprosy perforator Loss of skin substance with a torpid evolution located in the plantar support points of patients with neuropathy due to Mycobacterium leprae, characterized by a painless bed and very thick calloused hyperkeratotic edges.

Also: bad Hansen piercing · neurotrophic leprosy ulcer

Plantar neuropathic ulcer of the diabetic foot Deep, chronic and painless solution located in the areas of greatest pressure or friction on the sole of the foot, surrounded by a hyperkeratotic border or thick callus. It is a direct consequence of the loss of proprioceptive and nociceptive sensitivity.

Also: bad diabetic plantar perforator · painless plantar neurotrophic ulcer

Painless plantar neuropathic ulcer Loss of skin substance of chronic evolution that compromises the epidermis, dermis and subcutaneous tissue, located in areas of support of the foot subjected to repeated mechanical pressure that lack painful sensitivity. It is typical of diabetic neuropathy and leprosy, characterized by a thick hyperkeratotic border.

Also: plantar neurotrophic ulcer

Chronic venous leg ulcer Skin continuity solution with irregular edges, background with slough or deficient granulation tissue, located in the lower third of the leg and associated with signs of chronic venous insufficiency such as hyperpigmentation and edema. Clinically, it presents with moderate pain that is relieved by elevating the extremity.

Also: varicose ulcer · venous stasis ulcer

Immediate skin urticaria Phenomenon characterized by the rapid appearance of edematous, pruritic and individual skin hives or hives that change location and disappear in less than twenty-four hours without leaving sequelae. It is caused by the acute degranulation of mast cells with the release of histamine in the dermis.

Also: outbreak of hives · dermal edema from urticaria

Leukocytoclastic vasculitis of dermal vessels Necrotizing inflammation that selectively affects the capillaries and postcapillary venules of the dermis, characterized histologically by fibrinoid necrosis of the vascular wall, neutrophilic infiltration and karyorrhexis. Clinically it manifests as bilateral palpable purpura.

Also: leukocytoclastic vasculitis · necrotizing vasculitis of small vessels

Dermal leukocytoclastic vasculitis Acute inflammation of the small vessels of the dermis characterized histologically by fibrinoid necrosis of the vascular wall, infiltration of neutrophils, extravasation of erythrocytes and the presence of karyorrhexis or nuclear dust. Clinically it manifests as palpable purpura that does not clear up to pressure.

Also: hypersensitivity vasculitis · cutaneous small vessel vasculitis

Dermatological vegetation of condyloma acuminatum Lobulated, soft and pink exophytic proliferation constituted by papillary projections of the epithelium covered by a thin and moist corneal layer, located in the anogenital region due to human papillomavirus infection. It is grouped in plates with cauliflower morphology.

Also: exophytic genital wart · anogenital condylomatous vegetation

Warty dermatological vegetation Exophytic elevated skin proliferation consisting of thin epithelial projections covered with a thin, moist corneous layer, frequently located in areas of body folds or mucous membranes. It is observed in condylomata acuminata and pemphigus vegetans.

Also: moist skin vegetation · exophytic vegetative growth

Dry skin wart Raised, hyperkeratotic skin proliferation with an anfractuous, rough, dry, grayish or brownish surface, resulting from papillomatosis and a marked supraadjacent orthokeratotic hyperkeratosis. It is the defining lesion of verruca vulgaris and verrucous cutaneous tuberculosis.

Also: dry warty growth · keratotic warty lesion

Dry cutaneous wart of warty tuberculosis Raised skin elevation, hyperkeratotic, rough and dry to the touch, brownish in color, constituted by papillomatosis and marked epidermal acanthosis reactive to skin infection by mycobacteria. It is preferentially located on the extremities.

Also: warty plaque of tuberculosis · tuberculosis cutis verrucosa

Spongiotic intraepidermal vesicle Microscopic or macroscopic liquid collection located in the thickness of the epidermis, caused by the breakdown of intercellular bridges between keratinocytes due to the severe accumulation of intercellular edema or spongiosis. It is the elementary histological lesion of acute eczema.

Also: spongiotic vesicle · acute eczema gallbladder

Spongiotic intraepidermal vesicle of atopic dermatitis Microscopic fluid collection in the epidermal stratum spinosum caused by the accumulation of intercellular edema that separates the keratinocytes, associated with a reactive inflammatory infiltrate of lymphocytes and eosinophils. It is characteristic of the acute phase of atopic dermatitis.

Also: atopic vesicle · acute atopic eczema vesicle

Spongiotic intraepidermal vesicle of eczema Submillimeter or millimeter liquid collection located in the thickness of the epidermis, caused by the breakdown of intercellular bridges between keratinocytes due to the severe accumulation of edema or spongiosis. It is the defining lesion of acute eczematous processes.

Also: eczema gallbladder · spongiotic vesicle of acute eczema

Multilocular spongiotic intraepidermal vesicle Intraepidermal cavitated lesion composed of multiple lobes or remaining cellular septa, caused by the coalescence of areas of severe spongiosis in acute eczemas. Clinically it manifests as a highly tense multilocular vesicle.

Also: multilocular vesicle of eczema · septated spongiotic blister

Subepidermal vesicle due to cleavage Collection of liquid content located precisely in the dermoepidermal space, caused by the separation or cleavage of the epidermis from the dermis due to the destruction of the basement membrane or hemidesmosomes. It is characteristic of pemphigoid, epidermolysis bullosa and burns.

Also: dermoepidermal vesicle · small subepidermal blister

Aseptic intraepidermal vesiculopustule Raised and cavitated lesion that contains a variable mixture of transparent serum and predominantly neutrophilic inflammatory cells, located in the superficial layers of the epidermis without the presence of bacteria. It is commonly observed in sterile superinfected miliaria pustulosa and eczema.

Also: aseptic vesiculopustule · epidermal vesiclepustule

Intraepidermal vesiculopustule of miliaria pustulosa Raised cavitated lesion of sterile purulent content located in the superficial layers of the epidermis, which originates from the obstruction of the eccrine sweat duct with inflammation of neutrophils around it. It commonly occurs in warm climates.

Also: pustular miliaria · aseptic eccrine vesiculopustule

Dermatology

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