Syphilis: what it is and why it matters

Syphilis is a bacterial infection spread mainly through sexual contact. It starts with one small sore that you might not even notice, then can move into a rash and later cause serious problems if it’s not treated. The good news: early syphilis is easy to cure with the right antibiotics. The important part is knowing the signs, getting tested, and treating it quickly—especially in pregnancy.

How syphilis spreads and shows up

The infection comes from the bacterium Treponema pallidum. You can catch it during vaginal, anal, or oral sex when you come into contact with an infected sore. Early symptoms include a single painless ulcer (called a chancre) at the infection site. Weeks to months later you might get a rash on the body or palms and soles, swollen lymph nodes, fever, or flu-like symptoms. After that, syphilis can enter a hidden phase with no symptoms and later cause heart, nerve, or brain damage if untreated.

Pregnant people with syphilis can pass it to the baby before birth. That can cause miscarriage, stillbirth, or a newborn with serious health problems. If you’re pregnant, testing and treatment are urgent and effective—penicillin is the standard and works well to prevent congenital syphilis.

Testing and treatment — what to expect

Doctors usually do a blood test. Labs often run a non-treponemal test (RPR or VDRL) plus a confirmatory treponemal test (TP-PA or FTA-ABS). Testing can miss very recent infections because antibodies take time to show up, so repeat testing may be needed if exposure was recent.

Treatment depends on the infection stage. For early syphilis, a single intramuscular injection of benzathine penicillin G usually cures it. For later stages, multiple doses are given. If you’re allergic to penicillin, your provider may use other antibiotics or recommend penicillin desensitization—this is common advice for pregnant patients because penicillin is the safest option for the baby.

After treatment, follow-up blood tests at 3, 6, and 12 months track response to therapy. You should avoid sex until you and any partners finish treatment and tests show the infection is cleared. Tell recent partners so they can get tested; partner treatment helps stop spread and prevents reinfection.

Prevention is practical: use condoms, reduce the number of sexual partners, and get regular STI screenings if you’re sexually active—especially if you’re in a higher-risk group or pregnant. If you notice a sore, rash, or unexplained symptoms after a sexual encounter, see a clinic or healthcare provider promptly. Quick testing and treatment protect you and others.

If you want links to official guidance or local testing centers, I can help find them for your area.