The first sign of syphilis is a small sore, called a chancre. The sore appears at the spot where the bacteria entered body. While most people infected with Treponema pallidum develop only one chancre, some develop several of them. The chancre usually develops about three weeks after exposure. Many people who have syphilis don’t notice the chancre because it’s usually painless, and it may be hidden within the vagina or rectum. The chancre will heal on its own within three to six weeks.