A young long-distance lorry driver presents to the clinician with a painless penile ulcer 9 days after sexual intercourse with a professional sex worker. What is the likely diagnosis?

Chancre is a sign of primary syphilis which occurs within 2-3 weeks of initial inoculation. The lesion is characteristically painless. It is initially a dull red macule which becomes papular and fuher erodes to become an indurated ulcer called chancre. These lesions resolves spontaneously within 2 months if not treated. Herpes, Chancroid and Traumatic ulcer are painful lesions. Ref: Davidson's Principles and Practice of Medicine, By Sir Stanley Davidson, Christopher Haslett, 2002, Page 97.