Clinical manifestations of primary syphilis in homosexual men.

At the beginning of a new millennium, syphilis incidence has been increasing worldwide, occurring primarily among men who have sex with men (MSM). The clinical features of primary syphilis among MSM is described, a case-note review of the primary syphilis (PS) patients who attended the Institute of Skin and Venereal Diseases. The diagnosis was assessed based upon the clinical features and positive syphilis serology tests. Among 25 patients with early syphilis referred during 2010, PS was diagnosed in a total of 13 cases. In all patients, unprotected oral sex was the only possible route of transmission, and two out of 13 patients had HIV co-infection. Overall, 77% of men presented with atypical penile manifestation. The VDRL test was positive with low titers. The numerous atypical clinical presentations of PS emphasize the importance of continuing education of non-experienced physicians, especially in countries with lower reported incidence of syphilis.