An ulcerative lip lesion

A woman in her 20s presented with a painful lesion on the upper lip. The lesion had appeared three weeks earlier as a papule and progressed to a painful ulcer. The patient had no history of vesicles prior to this presentation. She had initially received a diagnosis of herpes simplex, but after taking systemic antivirals for two weeks had seen no improvement in her condition. Physical examination showed a round, hard, erythematous nodule, approximately 1 cm in diameter, with an ulcer and a convex eroded surface on the upper lip (fig 1). When compressed, serous fluid exuded from the ulcerative surface. The woman had no lesions on the genitals or other areas of the body, and no palpable cervical lymphadenopathy. She had no history of previous sexually transmitted infection, and her family history …