Discoid Lupus Erythematosus

A 46-year-old man complained of “irritation” in the groin of several months’ duration. Ted Rosen, MD, of Houston noted a tender, macerated, hypopigmented plaque at the junction of the scrotum and upper inner thigh. At the periphery of the lesion was some detectable erythema and within the plaque were several small, superficial erosions. The differential diagnosis included Bowen disease (squamous cell carcinoma in situ), candidiasis, and discoid lupus erythematosus. A thorough cutaneous examination revealed one small, similar-appearing lesion in the right ear canal. Review of systems was entirely unremarkable. A biopsy of both lesions showed histologic changes compatible with discoid lupus erythematosus; results of an antinuclear antibody assay and other laboratory screening tests were negative or normal. While discoid lupus erythematosus is uncommon in the groin, it can affect any part of the body, even areas that are usually not exposed to sun. In patients with lesions both above and below the neck, underlying disease must be ruled out. Treatment options for cutaneous disease include topical corticosteroids and retinoids, as well as systemic antimalarial agents, corticosteroids, and dapsone. Advise patients to use sun protection. This patient was treated with topical midpotency corticosteroid cream and oral hydroxychloroquine, 200 mg bid. Eight weeks later, the erythema had resolved and the erosions had healed.