Discoid lupus erythematosus

Definition

A rare form of chronic cutaneous lupus erythematosus characterized by erythematous, scaly papules and plaques preferentially occurring on sun-exposed skin areas (scalp, face, and ears) and exhibiting follicular plugging, pigmentary changes, and central atrophy, scarring, and telangiectasia. Skin biopsy shows a perivascular and periadnexal lymphocytic infiltrate and involvement of the dermoepidermal junction with thickening of the basement membrane and vacuolar degeneration of the basal cells. A small percentage of patients may develop systemic lupus erythematosus.