0.127 Images of memorable cases: case 145

145. syphilitic chancre

The primary stage of infection with the spirochete Treponema pallidum . Ten to 90 days after exposure, the chancre appears at the site of innoculation—usually the anogenital area butsometimes the lip, tongue, or tonsil. It begins as a maculopapule, undergoes ischemic necrosis, and ends up with raised, smooth, sharply defined borders. Thelesion is painless and ranges from 0.3 cm to 2 cm in diameter. It heals spontaneously in 4-14 weeks or within a week or so when treated.

Finding spirochetes under dark field microscopy or obtaining positive serologic tests for syphilis confirms the diagnosis. Thedifferential diagnosis includes chancroid, granuloma inguinale, lymphogranuloma venereum, and penile carcinoma.

In the patient shown, dark field microscopy was positive and response to therapy was rapid and complete.