Patients with chancre of syphilis mainly present with small erythematous spots on the external genitalia, most often on the penis, glans, prepuce and ligament in men, and on the labia, perineum and uterine opening in women. The erythema becomes necrotic and forms a painless round or oval ulcer 1-2 cm in diameter, which is difficult to detect because it is painless. 1-2 weeks after the appearance of the hard chancre, the lymph nodes in the groin or near the affected area are visibly enlarged but painless. The chancre usually begins about 2-3 weeks after syphilis infection and usually has no systemic symptoms, but there can be enlarged lymph nodes. The chancre is highly contagious and can last for 3-4 weeks or more in untreated patients, while in treated patients it may subside in 1-2 weeks, leaving a dark red scar or discoloration of the skin in this area, which does not mean that the infection has disappeared.