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 of 1 year's duration.No history of injury to the scalp was noted.The patient noticed hair loss in the affected area in the month prior to presentation.She was afebrile and otherwise asymptomatic.She denied a family history of similar scalp disorders. WHAT'S THE DIAGNOSIS?a. discoid lupus erythematosus b. dissecting cellulitis of the scalp c. follicular lichen planus d. folliculitis keloidalis nuchae e. tufted hair folliculitis