A Rare Coexistence of Alopecia Areata and Lichen Planus

In the 2019 case report, a 45-year-old Caucasian male with a history of type 2 diabetes mellitus presented with an 18-month history of a pruritic rash in the genital area and a 12-month history of hair loss on the forearm. Dermatological examination revealed a well-demarcated, annular patch of hair loss on the forearm and multiple erythematous papules on the glans penis. Histopathological evaluation of the alopecic patch showed perifollicular fibrosis and mild lymphocytic infiltration, while the glans penis showed parakeratosis, acanthosis, and lymphocytic infiltrate, leading to a diagnosis of coexisting alopecia areata and lichen planus. The patient was treated with 0.1% hydrocortisone butyrate ointment and advised to follow up in two weeks. The report highlights the rarity of the coexistence of these two conditions and suggests that a common antigenic determinant may trigger both diseases.