Syphilis: symptoms, diagnosis, treatment and prevention
Table of Contents
Key takeaways
- Syphilis is a sexually transmitted infection that can cause serious problems if it is not treated, including complications in pregnancy.
- Symptoms can be mild, hidden or come and go, so testing is the only way to confirm whether syphilis is present.
- Treatment usually involves antibiotics through a GP or sexual health clinic, and sexual partners may also need testing and treatment.
- Avoid vaginal, anal and oral sex until advised it is safe after treatment, and seek prompt care if pregnant or exposed to syphilis.
Overview
Syphilis is a bacterial sexually transmitted infection caused by Treponema pallidum. It can affect the genitals, anus, mouth, skin, nervous system, eyes, ears, heart and pregnancy. Early symptoms may be painless or easy to miss, which is why NHS guidance emphasises testing rather than relying on symptoms alone.
This article is classified as sexual_health with medical-condition depth. Mayo Clinic’s syphilis condition page was used as a benchmark for completeness, including stages, transmission, complications, diagnosis, treatment and prevention, while NHS guidance was prioritised for UK testing and sexual health clinic pathways.
Symptoms by stage
In early syphilis, the first sign may be one or more small sores or ulcers on the vagina, penis, anus, mouth, lips, hands or bottom. These sores are often painless, so a person may not notice them, especially if they are inside the vagina or anus. Later symptoms can include a rash on the palms and soles, white or grey wart-like growths around the genitals or anus, white patches in the mouth, swollen glands, fever, headaches, tiredness and patchy hair loss.
Symptoms may improve or disappear without treatment, but that does not mean the infection has gone. Syphilis can move into a latent stage with no visible symptoms. If untreated, it can later cause serious problems affecting the heart, brain, nerves, eyes, hearing, bones, joints, skin, liver and other organs. During pregnancy, syphilis can be passed to the baby and is linked with miscarriage, premature birth, stillbirth and congenital infection.
Because symptoms can overlap with other conditions, syphilis can be mistaken for herpes, mouth ulcers, piles, a nonspecific rash, glandular fever, eczema, psoriasis or another STI. A painless sore is especially easy to miss if it is internal. Any new genital, anal or mouth ulcer after sexual contact should be checked rather than covered with creams or left until it disappears.
How syphilis spreads
Syphilis most commonly spreads through vaginal, anal or oral sex when there is direct contact with an infectious sore. It can also be passed during pregnancy to an unborn baby. NHS guidance also notes possible spread through injecting drugs with a needle used by someone with syphilis, while transmission through blood or organ donation is rare in the UK because donations are checked.
Syphilis is not a judgement about someone’s behaviour. Anyone who is sexually active can be exposed. Risk is higher after sex without a condom or dam, with a new partner, if a partner has an STI, or when sharing injecting equipment. Having another STI can also make it sensible to test for syphilis and other infections at the same time.
It is possible to have syphilis and not know, so prevention relies on testing as well as barrier protection. Condoms and dams reduce risk but may not cover every sore. This is why a sexual health clinic may recommend testing even when a condom was used, especially if there are symptoms, a partner notification, pregnancy, HIV, or other STI concerns.
Testing and diagnosis
A test is the only way to confirm syphilis. In the UK, STI tests are available free through NHS sexual health services. A clinician may examine the genitals, anus, mouth and skin, take a swab from a sore if present, and take a blood sample. Pregnant people are offered antenatal screening for syphilis so that infection can be found and treated before it causes serious harm.
Testing can feel embarrassing, but sexual health clinics are used to seeing these symptoms and can help with confidential partner notification. It is reasonable to ask what infections are being tested for, when results will be available, whether repeat testing is needed, and what to do about sex while waiting.
Timing can matter. If exposure was very recent, an early test may not always show infection, so the clinic may advise repeat testing. If there is a visible sore, swab testing may be useful alongside blood tests. People diagnosed with syphilis are often offered tests for HIV, gonorrhoea, chlamydia and other STIs because infections can occur together and treatment plans may need to account for the whole picture.
Treatment and follow-up
Syphilis is treated with antibiotics, which may be given as injections, tablets or capsules depending on the stage and clinical circumstances. Treatment may start before test results are back if the clinician thinks syphilis is likely. Some people feel flu-like symptoms within the first 24 hours after treatment; a clinic can advise how to manage this and when to seek help.
Follow-up matters. NHS guidance says people need to return to the GP surgery or sexual health clinic several times in the first 12 months after starting treatment to be retested. This checks that treatment has worked and helps identify possible reinfection. Do not have vaginal, anal or oral sex until two weeks after both you and your partner have finished treatment, or until the clinic gives specific advice.
Do not try to treat syphilis with leftover antibiotics, online medicines or supplements. The choice and duration of treatment depend on the stage, pregnancy status, allergy history, symptoms involving the eyes, ears or nervous system, and previous results. Delayed or incomplete treatment can allow complications to develop and can leave partners at risk.
Prevention and partner notification
Condoms for vaginal and anal sex and condoms or dental dams for oral sex reduce risk, though they only protect the areas they cover. Do not share sex toys without washing them and covering them with a new condom between users. Do not share needles or injecting equipment.
If syphilis is diagnosed, current and recent sexual partners need testing and may need treatment. Clinics can help notify partners without naming you. This is not about blame; it prevents reinfection and protects partners and, where relevant, pregnancies.
When to seek medical advice
Go to a sexual health clinic or see a GP if you or a partner has symptoms of syphilis, a partner tells you they have syphilis or another STI, you have had sex with a new partner without a condom, you are pregnant or planning pregnancy and may have been exposed, or you have shared injecting equipment. Seek urgent advice for severe headache, confusion, weakness, vision changes, eye pain, hearing changes, chest pain or symptoms in pregnancy.
Sources
- NHS, Syphilis: https://www.nhs.uk/conditions/syphilis/
Relevance: UK guidance on symptoms, testing, treatment, complications, pregnancy, transmission and prevention. - Mayo Clinic, Syphilis symptoms and causes: mayoclinic.org guidance page link unavailable during validation (mayoclinic.org guidance page, link unavailable during validation)
Relevance: Mayo Clinic condition benchmark for stages, organ complications, pregnancy risks, transmission and when to seek care. - Mayo Clinic, Syphilis diagnosis and treatment: mayoclinic.org guidance page link unavailable during validation (mayoclinic.org guidance page, link unavailable during validation)
Relevance: Supports discussion of blood tests, swab testing, treatment and follow-up. - CDC, About syphilis: https://www.cdc.gov/syphilis/about/index.html
Relevance: Public-health source supporting staged symptoms, congenital syphilis risk and prevention principles.
Disclaimer
Educational only. Results vary. Not a cure. Use NHS 111 for urgent advice or call 999 in a life-threatening emergency.