What organism causes syphilis?

Treponema pallidum is a thin, spiral-shaped bacterium. After entering the body, it may first cause a sore at the point of contact. Later, skin changes, swollen glands, or other symptoms can appear, and some people have no noticeable symptoms. Untreated infection can remain in the body and may damage organs over time. A visible sore or rash is not needed for transmission, so appearance alone cannot confirm or exclude syphilis.

Arrange a clinical assessment if you have had sexual contact that may have exposed you, notice an unusual sore or rash, or have a partner diagnosed with syphilis. A clinician can choose blood tests and, when appropriate, examine a sore. Avoid sexual contact until you receive individual advice, and tell recent partners so they can seek assessment. Syphilis is treatable with prescribed antibiotics; do not use leftover medicine or share treatment.

Seek prompt medical care for a new genital, anal, mouth, or skin sore, a widespread rash involving the palms or soles, or swollen glands after a possible exposure. Get urgent help for vision changes, severe headache, weakness, confusion, hearing changes, or problems with balance, because syphilis can sometimes involve the eyes, ears, or nervous system. Pregnancy also warrants prompt testing after a possible exposure.

Ask which tests are suitable, whether repeat testing is needed after a recent exposure, whether partners should be assessed, and when sexual contact can safely resume. Confirm the antibiotic plan, follow-up arrangements, and which symptoms should trigger an earlier review.