What are the common symptoms of primary syphilis?

The common symptoms of primary syphilis mainly include hard chancre and lymphadenopathy. Specifically:

1. Hard Chancre: This is the hallmark symptom of syphilis, typically appearing 2 to 3 weeks after infection with Treponema pallidum. It initially presents as a small red spot on the external genitalia, which rapidly progresses to a painless ulcer approximately 1 to 2 cm in diameter. The ulcer is usually round or oval in shape, with well-defined borders, and feels firm and cartilage-like upon palpation. There is neither pain nor tenderness. Hard chancre commonly occurs on the penis, glans, foreskin, and frenulum (in males) or the labia, perineum, and cervix (in females). This symptom is highly contagious and may persist for several weeks to several months. Even after spontaneous resolution, the infection may still remain contagious.

2. Lymphadenopathy: One to two weeks after the appearance of the hard chancre, the inguinal lymph nodes or those near the affected area may become noticeably enlarged, although typically without pain. This lymph node swelling is another important clinical sign of syphilis infection.

Although symptoms of primary syphilis are relatively localized, without timely treatment, the disease may progress to more severe stages. Therefore, prompt medical attention and standardized treatment should be sought once the above symptoms appear.