The primary sore of syphilis is?

The primary sore of syphilis is known as a chancre. It typically develops at the site of inoculation of the Treponema pallidum bacteria, which causes syphilis. The chancre usually appears within 10-90 days after exposure to the bacteria and presents as a painless, indurated (firm to the touch), and round or oval-shaped ulcer with raised borders. It commonly occurs on the genitals, but it can also manifest in other areas, such as the rectum, mouth, or fingers. The chancre typically lasts for 2-6 weeks before spontaneously resolving.