Erythematous Plaque on the Scalp With Alopecia

A 37-year-old woman presented with a 2×6-cm, firm, erythematous plaque on the parietal region of the scalp, which had been present for 1 year. She experienced hair loss in the affected area a month before seeking medical attention. She had no history of scalp injury, was afebrile, asymptomatic, and had no family history of similar scalp disorders. The differential diagnosis included discoid lupus erythematosus, dissecting cellulitis of the scalp, follicular lichen planus, folliculitis keloidalis nuchae, and tufted hair folliculitis.