Indurated plate

Specialty: Skin.

• infiltrated skin plaque
• skin induration
• plate firm to the touch

Why it occurs

• Localized morphea or scleroderma (excessive deposition of dense collagen in the papillary and interstitial dermis)
• Cutaneous sarcoidosis (dermal granulomatous infiltration of epithelioid cells without caseation necrosis)
• Cutaneous T-cell lymphoma in plaque phase (infiltrate of neoplastic T lymphocytes with epidermotropism)
• Tumidus or deep lupus erythematosus (dense perivascular and periadnexal lymphocytic infiltration with dermal mucinosis)
• Chronic lipodermatosclerosis of the lower limbs secondary to venous hypertension.

Initial workup

Incisional biopsy with a 4 or 6 mm punch of skin that extends from the epidermis to the subcutaneous cellular tissue (essential for pathological diagnosis). Complementary laboratory tests: complete blood count, erythrocyte sedimentation rate (ESR), angiotensin-converting enzyme (ACE) levels if sarcoidosis is suspected, antinuclear antibodies (ANA) and skin immunohistochemistry to type lymphocytic infiltrates.

Standard management

• Clobetasol propionate 0.05% cream or ointment applied under occlusion — corticoid of choice to reduce local inflammatory cellular infiltration
• Methotrexate — immunosuppressant indicated if the plaque is due to systemic sarcoidosis or linear/extensive morphea, dose of 15 to 25 mg weekly orally
• Hydroxychloroquine — synthetic antimalarial indicated if histology confirms lupus tumidus or cutaneous sarcoidosis, dose of 200 to 400 mg daily
• Intralesional triamcinolone (local infiltration of 10 to 20 mg/mL to reduce the consistency and size of the infiltrated plaque).