Coilonychia

Specialty: Skin.

• spoon nails
• concave nail dystrophy

Why it occurs

• Severe and chronic iron deficiency anemia (iron deficiency alters keratin synthesis in the nail matrix)
• Idiopathic or familial hereditary (benign autosomal dominant trait, common temporarily in infants)
• Systemic hemochromatosis (tissue iron overload that damages the nail matrix)
• Chronic occupational trauma or prolonged exposure to organic solvents derived from petroleum
• Systemic collagen diseases such as systemic lupus erythematosus or severe Raynaud's syndrome.

Initial workup

Complete blood count, serum iron levels, total iron binding capacity (TIBC), serum ferritin (most sensitive marker of iron deficiency) and transferrin saturation index. If hemochromatosis is suspected: genetic studies (HFE mutations) and serum lead levels if occupational environmental exposure is suspected.

Standard management

• Sulfato ferroso — oral iron supplement to correct underlying iron deficiency, usually 300 mg daily equivalent to 60 mg of elemental iron, administered together with vitamin C to optimize absorption
• Iron carboxymaltose — intravenous administration if there is severe gastric intolerance or diagnosed malabsorption
• Local emollients to protect the cuticle and distorted nail plate.