A 19-year-old woman presented with erosions on both nipples. Pruritic skin lesions had formed gradually over 4 weeks after a bite during sexual intercourse and persisted for approximately 8 weeks. No significant change in size or morphologic characteristics of these lesions occurred during the 8 weeks. The lesions were painless; neither fever nor associated systemic symptoms were noted. Three months later, the patient presented with an asymptomatic skin eruption. Physical examination revealed erythematous erosive patches on both nipples (Figure, A and B) and pink macules on the trunk. Lymphadenopathy and mucosal lesions were absent. Punch biopsy specimens were obtained from both nipples for histopathologic analysis (Figure, C and D).