28th July 2023

A 50 year old man, who has a history of sexual intercourse with men, attends with a 5 day history of a single, painless ulcer

A 50 year old man, who has a history of sexual intercourse with men, attends with a 5 day history of a single, painless ulcer on the shaft of his penis. His last sexual intercourse was 10 days ago, without barrier contraception. There is no fever, discharge, anal pain, or skin rash.

What diagnostic test is most likely to give the diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.