What is the main feature of primary syphilis?

1 Answer

That would be the chancre ...

Explanation:

Syphilis is acquired by having (unprotected) sex with an infected partner. Within 3 months (average is 3 weeks) a (painless) ulceration, or sore called a Chancre will form.

In most instances this lesion will appear on the penis or the vagina, but can also manifest itself on or around the mouth or anus (depending on the type of sexual contact).

The Chancre is infectious.
Even if left untreated the chancre can diminish, usually after 4-8 weeks. But this doesn't mean you are healed: the infection will remain, and will progress slowly but surely into the secondary and tertiary phases. This can take years, though....

For reasons of good taste, I decided not to include pictures of the lesions....

instead, may I present the offender:

Pathogen : Treponema pallidum

enter image source here

By Photo credit: CDC / Dr. David Cox - This media comes from the Centers for Disease Control and Prevention's Public Health Image Library (PHIL), with identification number #1977.