A 25-year-old unmarried man was referred because of 1-week history of mildly sore throat, without association of systemic symptoms. He had an oral sex with a man 3 weeks before his presentation. His-past medical histories were unremarkable. Examination showed a well-delimited plaque with central ulceration on the right retropharyngeal wall, covered with white pseudomembranes and surrounded by erythema (Figure 1). No other rashes were detected elsewhere. Laboratory tests for complete blood cell count, erythrocyte sedimentation rate, biochemistry profiles, C-reactive protein, anti-nuclear antibodies, auto-antibodies and HIV were either within normal limits or negative.
