Seronegative secondary syphilis in an HIV-infected patient.

Recently, increased rates of syphilis among gay men have been observed in American and European cities. It is important to establish the diagnosis because syphilis facilitates HIV transmission during the primary and secondary stages when sores are open on the skin. However the diagnosis can present a dilemma as negative reactions to serological tests may be observed in AIDS patients. We report here such a case in which the diagnosis was established on dark field examination.