Perianal Ulcer in an Asian Man.

A 79-year-old Chinese man presented with a 2-month history of pruritic, tender ulceration covering his perianal region. He was initially treated with oral amoxicillin/clavulanic acid and vancyclovir, with no improvement. His history included hypertension. On physical examination, there was a 1.5-cm solitary, pink shallow ulcer with a tender erythematous base on the right side of the buttock cleft (Figure 1).