This patient presented with a primary anorectal syphilitic chancre during the primary stage of the disease.

Syphilis is an infectious disease caused by the corkscrew-shaped spirochete bacterium, Treponema pallidum. Primary syphilis usually presents itself as a genital ulcer, or chancre that is usually firm, round, small and painless, and appears at the spot where T. pallidum bacteria entered the recipient’s body. However, when anal intercourse is the mode of transmission, as was the case here, the site of inoculation can then be the anorectal region, hence, the reason for the anorectal location of the primary syphilitic chancre.

Content Providers(s): CDC/Susan Lindsley, VD