What is syphilis, and how do you catch it?
Syphilis is a bacterial infection caused by Treponema pallidum. It spreads through direct contact with a syphilis sore during vaginal, anal or oral sex, and it moves through distinct stages over months to years. If it's never treated, it can eventually damage the heart, brain and other organs.
Diagnoses in England have risen over the past decade. In women the early stages are easy to miss, because the first sore often sits inside the vagina, on the cervix or around the anus, where only a clinical examination is likely to find it.
What does the first sign of syphilis look like?
The first sign is a chancre: a small, round, usually painless sore where the bacteria entered the body. It develops 10 to 90 days after exposure, with an average of around three weeks.
In women, the chancre commonly appears on the:
- Vulva (labia, clitoral hood)
- Inside the vagina, where it often goes unnoticed
- Cervix, which is invisible without a speculum examination
- Anus or perianal area
- Lips, mouth, or throat, after oral sex
Because it's painless, most women don't feel it, and an internal sore simply isn't seen. It heals within three to six weeks whether or not it's treated, which makes everything seem fine while the infection carries on.
We recommend a syphilis test for any woman with a new or casual sexual partner, even without symptoms, since a blood test finds what a physical examination might miss.
What happens if the chancre is missed?
Untreated primary syphilis moves into a second stage, usually four to ten weeks after the chancre first appeared. This stage tends to be more noticeable, though it's still often mistaken for something else.
The secondary syphilis rash has a distinctive pattern:
- It appears on the palms of the hands and soles of the feet, which is unusual for most rashes
- It can also spread across the trunk, arms, and legs
- It is typically red or reddish-brown and does not usually itch
Beyond the rash, secondary syphilis can cause flat, greyish-white, wart-like growths in warm, moist areas such as the vulva, anus or groin folds (condylomata lata). It can also bring patchy hair loss, a sore throat, swollen lymph nodes, fever, tiredness, white patches inside the mouth and headache.
These symptoms also settle by themselves within a few weeks to months, and the infection is still there when they do.
Syphilis stages in women
The table below sets out the pattern most women experience, and what tends to be missed at each stage.
What is the latent stage?
After the secondary symptoms clear, syphilis moves into a latent, hidden stage. There are no visible symptoms, but the bacteria remain in the body. Latent syphilis is described as early, within about two years of infection, when it can still be passed on, or late, beyond that point.
Only a blood test can find latent syphilis. This is the stage where many women are finally diagnosed, often during routine pregnancy screening or a sexual health screen. Left untreated for years, a minority of people develop late-stage complications affecting the heart, nervous system, skin or bones. A rash that has already faded is still worth testing for that reason.
Why is syphilis so often missed in women?
The primary chancre is painless and frequently internal. A herpes outbreak is usually painful and visible, whereas a syphilis sore causes no discomfort, and on the cervix only a speculum examination will find it.
The secondary rash looks like other things. Dermatitis, an allergic reaction and a viral rash are all more common explanations. The palms-and-soles pattern is a useful clue, though not every case follows the textbook.
Symptoms also come and go. Each stage settles on its own, leaving gaps where a woman feels fine. The same painless pattern catches men out too, as our guide to syphilis symptoms in men explains.
Syphilis and pregnancy
Syphilis in pregnancy needs prompt attention, because Treponema pallidum can cross the placenta. Untreated infection can lead to miscarriage, stillbirth, premature birth and serious health problems for the baby.
All pregnant women in the UK are screened for syphilis at their booking appointment, but that screen won't pick up an infection caught afterwards. If you're pregnant or planning a pregnancy and have had a new partner, a syphilis test is worth having whatever your symptoms. If you're already pregnant, tell your midwife too, as a repeat test later in pregnancy can be arranged when there's a new risk.
Who should test for syphilis?
Testing is generally recommended for:
- Anyone with symptoms suggestive of syphilis, such as a painless sore or an unexplained rash, especially on the palms and soles
- Women with a new sexual partner or multiple partners
- Women whose partner has been diagnosed with syphilis
- Pregnant women, in addition to standard NHS screening, if there has been a new partner since booking
- Women who have sex with women, since the infection can spread through skin-to-skin and oral contact with a sore
- Anyone diagnosed with another STI, since having one STI makes another more likely
- Anyone with a known exposure to syphilis
How is syphilis treated?
Treatment, when it's needed, is an injection given in-house at the clinic. It's usually given at a follow-up visit once your results are back, rather than on the day of testing. Treatment is charged separately from the test, at £275, which covers both the consultation and the medication. Our syphilis treatment page explains what's involved, including options if you have a penicillin allergy.
How testing works at our Harley Street clinic
A syphilis blood test is £85 plus a £50 blood draw (£135 total), with results in about 24 hours. If you have a visible sore, a clinician can look at it at the same visit, alongside the blood test.
Every one of our screening packages for women includes syphilis. Bronze, £250, covers chlamydia, gonorrhoea, HIV and syphilis, and Silver (£375), Gold (£490) and Platinum (£665) add further infections. Results for blood tests come back in about 24 hours, and urine and swab results within 3 working days.
If you need every result the same day, the FAST Screen Simple, £350, covers HIV, syphilis, chlamydia and gonorrhoea, and the FAST Screen Complex, £450, adds hepatitis B and C. Both return all results in 6 hours, as our guide to same-day STI test results explains.
You can walk in seven days a week at 117a Harley Street, and the visit is confidential, as with all of our private STI testing in London. If you're unsure whether a particular incident counts as a risk, our known exposure page can help. Our STI prevention page covers how to lower your risk of reinfection.
Book a syphilis test at 117a Harley Street. Walk in seven days a week, or book online.
References
- UKHSA: Sexually transmitted infections surveillance data
- BASHH: UK national guidelines on the management of syphilis
- NICE CKS: Syphilis
- NHS: Syphilis
