Syphilis is a bacterial infection that is usually caught by having sex with someone who is infected.
The bacteria that cause syphilis are called Treponema pallidum. They can enter your body if you have close contact with an infected sore, normally during vaginal, anal or oral sex, or by sharing sex toys with someone who is infected.

Pregnant women can pass the condition on to their unborn baby, which can cause stillbirth or the death of the baby shortly after labour.
It may also be possible to catch syphilis if you are an injecting drug user and you share a needle with somebody who is infected.
It is extremely rare for syphilis to be spread through blood transfusions, as all blood transfusions in the UK are tested for syphilis.
Syphilis also cannot be spread by using the same toilet, clothing, cutlery or bathroom as an infected person, as the bacteria cannot survive for long outside the human body.

Three stages of disease

The symptoms of syphilis develop in three stages, described below.

Stage 1 (primary syphilis) –

Symptoms of syphilis begin with a painless but highly infectious sore on the genitals, or sometimes around the mouth. If somebody else comes into close contact with the sore, typically during sexual contact, they can also become infected. The sore lasts two to six weeks before disappearing.

Stage 2 (secondary syphilis) –

Secondary symptoms, such as a skin rash and sore throat, then develop. These symptoms may disappear within a few weeks, after which you experience a latent (hidden) phase with no symptoms, which can last for years. After this, syphilis can progress to its third, most dangerous stage.

Stage 3 (tertiary syphilis) –

Around a third of people who are not treated for syphilis will develop tertiary syphilis. At this stage, it can cause serious damage to the body.
The primary and secondary stages are when you are most infectious to other people. In the latent phase (and usually around two years after becoming infected), syphilis cannot be passed on to others.
Tertiary syphilis is rare in the UK.

What to do

If you suspect you have syphilis, visit a genitourinary medicine (GUM) clinic, sexual health clinic or your GP as soon as possible.
The earlier syphilis is treated, the less chance there is of serious complications. Find your nearest sexual health clinic by searching by town or postcode.

How common is it?

The number of diagnoses of syphilis has risen substantially in the UK in the past decade. There have been several local outbreaks across England, the largest of which was in London between 2001 and 2004. Rates are highest among men who have sex with men.
However, syphilis is still one of the less common sexually transmitted infections in the UK. Between 2011 and 2012, there were 2,978 cases of syphilis diagnosed in the UK.


The symptoms of syphilis are the same for men and women, and can be difficult to recognise. They are often mild, which means you can pass on the infection without knowing you have it.
The symptoms develop in three stages:

  • primary syphilis
  • secondary syphilis
  • tertiary syphilis

Primary syphilis

The initial symptoms of syphilis can appear any time from 10 days to three months after you have been exposed to the infection.
The most common symptom is the appearance of a small, painless sore or ulcer called a chancre. The sore will appear on the part of your body where the infection was transmitted, typically the penis, vagina, or around the anus.
The sores can also appear in the mouth or on the lips, tonsils, fingers or buttocks. Most people only have one sore, but some people have more.
You may also experience swelling in your lymph glands (small organs found throughout the body, such as in the neck, groin or armpit).
The sore is painless and may be overlooked, so the condition can be spread without you realising you have an infection.
The sore will then disappear within two to six weeks. If the condition is not treated, syphilis will move into its second stage.

Secondary syphilis

The symptoms of secondary syphilis will begin a few weeks after the disappearance of the sore.
Symptoms can include:

  • a non-itchy skin rash appearing anywhere on the body, but commonly on the palms of the hands or soles of the feet
  • small skin growths, often mistaken for genital warts – on women these appear on the vulva and for both men and women they appear around the anus
  • flu-like symptoms – such as tiredness, headaches, joint pains and fever
  • swollen lymph glands
  • weight loss
  • patchy hair loss

These symptoms may disappear within a few weeks, or come and go over a period of months.

Latent phase

Without treatment, syphilis will then move into its latent (hidden) phase, where you will experience no symptoms, even though you remain infected.

Latent syphilis can still be passed on during the first year of this stage of the condition, usually through sexual or close physical contact. However, after a couple of years, you cannot pass the infection to others, even though you remain infected.

The latent stage can continue for many years (even decades) after you first become infected.
Latent syphilis is rare in the UK. However, without treatment, there is a risk that latent syphilis will move on to the third, most dangerous stage – tertiary syphilis.

Tertiary syphilis

The symptoms of tertiary syphilis can begin years or even decades after initial infection. Around a third of people who are not treated for syphilis develop serious symptoms at this stage.
The symptoms of tertiary syphilis will depend on what part of the body the infection spreads to. For example, it may affect the brain, nerves, eyes, heart, bones, skin or blood vessels, potentially causing any of the following symptoms:

  • stroke
  • dementia
  • loss of co-ordination
  • numbness
  • paralysis
  • blindness
  • deafness
  • heart disease
  • skin rashes

At this stage, syphilis can be dangerous enough to cause death.


Primary and secondary syphilis can be successfully treated with a single dose of penicillin, which is given as an injection into your buttock. You will be prescribed another antibiotic in tablet form if you are allergic to penicillin.
Later stages of the disease need to be treated with three penicillin injections, which are given at weekly intervals. Treatment usually lasts around two weeks, but can take longer in some cases.

Side effects of antibiotics

Some of the antibiotics used to treat syphilis can interfere with methods of contraception that contain the hormones oestrogen and progestogen, such as the combined pill or contraceptive patch.
Tell your doctor or nurse if you are using these methods of contraception so they can advise you on additional contraceptive methods to prevent you getting pregnant.

Refrain from any kind of sexual activity or close physical contact with another person until your treatment is complete and your sexual partner has been tested and treated.

Jarisch-Herxheimer reaction

A small number of people experience a reaction to the antibiotics, which is known as the Jarisch-Herxheimer reaction. It is thought that the reaction is triggered by the toxins released when a large number of bacteria are killed after antibiotic treatment.
The Jarisch-Herxheimer reaction causes flu-like symptoms such as fever, headaches and muscle and joint pain. These normally only last 24 hours, are nothing to worry about, and cause no serious problems.
The symptoms can be treated with paracetamol, but contact your GP or the genitourinary medicine (GUM) clinic if the symptoms are severe or do not settle down.

Follow-up test

Once the course of antibiotics has finished, you will be asked to return to the GUM clinic so a follow-up blood test can be carried out to check that the infection has gone.
You can still catch syphilis again, even after you have been successfully treated for it.

Tertiary syphilis

Treatment of tertiary syphilis requires longer courses of antibiotics and may need intravenous treatment (administered directly into the vein). While treatment can stop the infection, it cannot repair any damage that has already been caused by the tertiary syphilis.

Telling your partner

If you have syphilis, it is important that your current sexual partner, or any sexual partner you have had since being exposed to infection, is tested and treated.

Some people can feel angry, upset or embarrassed about discussing syphilis with their current partner or former partner. Do not be afraid to discuss your concerns with the clinic staff or your GP. They can advise you about who should be contacted and the best way to contact them.

The clinic can give you a “contact slip” to give to your partner or partners. This slip explains to that person that they may have been exposed to syphilis and that they should go for a check-up. The slip does not have your name on it and your details will remain totally confidential.

If you would prefer, the clinic can contact your recent partner for you. This is usually done by phone or letter. Again, your details will remain totally confidential and your partners will be given no information about you without your consent.

Nobody can force you to tell any of your partners about your syphilis, but it is strongly recommended. If it is left untested and untreated, syphilis can lead to death.

Pregnancy

Syphilis in pregnancy can be successfully treated using antibiotics. There are no risks to your unborn baby from the antibiotics.
It is vitally important that pregnant women receive treatment for syphilis because it can cause serious birth defects, miscarriage or stillbirth if it is left untreated.

Avoiding sex

Do not have vaginal, anal or oral sex and avoid any kind of skin contact with your partner until you have finished treatment.

Otherwise, you could be infected again or you could pass the infection on to someone else.

Complications

It is estimated that people with syphilis are three to five times more likely to catch HIV. This is because the genital sores caused by syphilis can bleed easily, making it easier for the HIV virus to enter the blood during sexual activity.
Infection with both HIV and syphilis can be serious because syphilis can progress much more rapidly than normal.


Preventing syphilis

The only guaranteed way to prevent a syphilis infection is to avoid sexual contact or to only have sexual contact with a faithful partner who has been tested and is not infected.

Male condoms and female condoms can reduce your risk of catching syphilis, but cannot prevent it altogether. You can still catch syphilis if your mouth makes contact with a sore on an infected person’s anus or vagina, for example.

It is important to not only use a condom during vaginal, oral and anal sex, but also consider using a dental dam (a square of soft plastic) when your mouth makes contact with your partner’s vagina or anus. This will reduce your risk of any sexually transmitted infection (STI), not just syphilis.

Avoid sharing sex toys. If you do share them, wash them or cover them with a condom before each use.
Sexual penetration or ejaculation does not need to take place for syphilis to spread.

If you are an injecting drug user, do not use other people’s needles. Many pharmacies and local authorities offer needle exchange programmes, where used needles can be exchanged for clean ones. Your GP or drug counsellor should be able to provide more information.