Hard chancre is the characteristic manifestation of stage I syphilis. It usually occurs 2 to 4 weeks after impure sexual intercourse and appears at the site of syphilis spirochete invasion, mainly on the external genitalia, and rarely on the lips, pharynx, and cervix, and commonly on the anus and rectum in gay men. The hard chancre is usually one or occasionally more than one. It starts as a papule or infiltrative erythema, followed by a mild erosion or superficial ulceration at the tip, which is covered with a small amount of mucus discharge or a thin gray crust with elevated margins and a cartilage-like hardness at the periphery. The chancre is 1-2 cm in diameter, round in shape and beef-colored, and is often accompanied by local lymph node enlargement. The chancre disappears spontaneously within 3-8 weeks even without treatment, while the swollen lymph nodes persist for a longer period of time.