Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum. The first major recorded epidemic of syphilis in Europe occurred in the late 15th century, particularly during the French invasion of Naples in 1494–1495. The origins of syphilis remain debated, with evidence suggesting that treponemal disease may have existed in Europe before this period.
Unlike many other STIs, syphilis is a systemic infection that can affect many parts of the body. Depending on the stage of infection, symptoms can involve the genitals, mouth, skin, lymph nodes, nervous system, eyes and cardiovascular system. If left untreated, it can cause serious complications years after the initial infection.
An effective treatment for syphilis was developed before penicillin, with Salvarsan introduced in 1910. Penicillin later became the preferred treatment, with its effectiveness against syphilis first reported in 1943. Penicillin remains the recommended treatment for syphilis today.
In recent decades, syphilis diagnoses have increased substantially in England. In 2024, there were 9,535 diagnoses of infectious syphilis, the highest number reported since the 1940s. However, the latest data show that infectious syphilis diagnoses fell by 13.5% in 2025 to 8,262, while increases continued among some groups, including heterosexual women.
Quick Overview
Symptoms
Early signs are usually painless sores. Later, a non-itchy rash or flu-like symptoms develop. Many have no symptoms. Consult our Specialists for advice.
Causes
Syphilis is caused by bacteria spread through close skin contact during vaginal, anal, or oral sex, or from a pregnant person to their baby.
Diagnosis
Diagnosis usually involves a blood test. If you have a sore, our Specialists can swab the area to check for the bacteria directly.
Treatment
Syphilis is typically treated with antibiotic injections, usually penicillin. Our Specialists will determine the exact treatment based on the stage of your infection.
Prevention
Use condoms consistently during vaginal, anal or oral sex to reduce risk, and attend STI screening when appropriate. Condoms do not fully prevent syphilis because sores can occur outside covered areas.
Prognosis
Syphilis is curable with antibiotics. Treatment stops the infection, but established neurological, cardiovascular or other tissue damage may not be reversible.
Contagiousness
Syphilis is infectious during the primary, secondary and early latent stages. Transmission occurs mainly through direct contact with infectious sores or lesions during vaginal, anal or oral sex. After the early stages, transmission through sexual contact becomes much less likely, although untreated infection can persist and cause complications. Prompt diagnosis and treatment reduce the risk of transmission and prevent progression.
Local to a multi-system disease
Syphilis begins at the site where bacteria enter the body but can spread through the bloodstream and lymphatic system. It is a multi-stage, multi-system disease, and neurological, ocular and otological involvement can occur at any stage.
Statistics
In England, 8,262 infectious syphilis diagnoses were recorded in 2025, a 13.5% decrease from 2024. However, diagnoses among heterosexual women increased by 4.8%, from 838 to 878. Globally, WHO estimated 8 million new syphilis infections among adults aged 15–49 in 2022.
Clinical Symptoms & Staging of Syphilis
Incubating Syphilis
The incubation period for syphilis refers to the time between coming into contact with the infection and the appearance of the first symptoms. On average, this takes about three weeks, but it can range anywhere from nine to ninety days. During this specific timeframe, a syphilis blood test may return a negative result because the infection is still in its earliest stages and may not yet be detectable by standard laboratory methods.
If you have been tested during this window and receive a negative result, it is still possible to develop symptoms or show a positive result on a repeat test several weeks later. In cases where there has been a known exposure to a partner with syphilis, our Specialists may offer what is known as epidemiological treatment. This involves providing the necessary antibiotics immediately, even if your initial test is negative, to prevent the infection from developing or being passed on to others. If you are worried about a recent exposure, it is important to discuss the timeline with our Specialists so they can help determine the best testing and treatment plan for your situation.
Primary Syphilis
Primary syphilis is the first stage of a syphilis infection. It typically begins with one or more small, painless sores known as chancres. These appear at the site where the infection first entered the body, such as the genitals, anus, or mouth. Because these sores are usually painless and can sometimes be hidden inside the vagina or rectum, they are often easy to miss.
You might also notice swollen lymph nodes near the area of the sore, such as in the groin or neck. This is your body's natural response to the infection. These symptoms usually develop about three weeks after exposure, although it can take anywhere from nine to ninety days.
Even without treatment, these sores will eventually heal on their own within a few weeks. However, this does not mean the infection has gone away. Without appropriate antibiotic treatment, the bacteria will remain in your body and progress to more serious stages, potentially affecting your long-term health.
If you have any concerns or believe you may have been exposed, it is important to speak with our Specialists. They can provide accurate testing and, if necessary, start the correct treatment to clear the infection and prevent it from spreading. Our Specialists may sometimes recommend treatment based on your history of exposure, even if an initial blood test is negative, as the infection can take time to show up in results.
Secondary Syphilis
Secondary syphilis usually develops around three months after infection, although the timing can vary. At this stage, the infection has spread throughout the body and commonly causes widespread skin and mucous membrane symptoms. Secondary syphilis is highly infectious, particularly when infectious mucocutaneous lesions are present.
Symptoms can include a widespread rash, which may involve the palms of the hands and soles of the feet, as well as swollen lymph nodes, fever, headaches, sore throat, fatigue and patchy hair loss. The rash may or may not be itchy. Other signs can include sores or patches affecting the mouth or genital area and condylomata lata, which are highly infectious lesions that commonly occur in warm, moist areas.
Secondary syphilis can also affect other parts of the body. Some people may develop inflammation of the liver or kidneys, while neurological or eye complications can also occur. Neurological, ocular and ear involvement can occur at different stages of syphilis and should not be regarded as features exclusive to tertiary disease.
For those who are pregnant, syphilis can be passed to the developing baby and may lead to serious pregnancy complications. The risk of transmission is highest with recent or untreated early infection, although transmission can occur with syphilis at any stage.
The symptoms of secondary syphilis may disappear even without treatment, but this does not mean the infection has cleared. Without appropriate treatment, syphilis can progress to latent and, in some people, later stages of disease. Our Specialists can provide testing and appropriate antibiotic treatment to manage the infection and reduce the risk of complications.
Latent Syphilis
Latent syphilis is a stage of infection where you have no visible signs or symptoms, but the infection remains in your body. It is usually identified through blood tests during a sexual health check-up. Because there are no symptoms to act as a warning, syphilis can remain undetected for a long time without treatment.
Under current UK guidance, latent syphilis is broadly classified as early latent when the infection was acquired within the preceding two years, and late latent when it was acquired more than two years ago. When it is not possible to establish when the infection was acquired, it is generally managed as late latent syphilis.
Although syphilis can be sexually transmitted during the infectious stages, latent syphilis itself is not generally considered sexually infectious because there are no active mucocutaneous lesions. However, syphilis can still be passed from a pregnant person to their baby during pregnancy.
Distinguishing between early and late latent syphilis is important because it helps our Specialists determine the appropriate treatment and follow-up. Treatment aims to clear the infection and prevent complications that can develop if syphilis remains untreated.
Even though you may feel perfectly well, it is important to complete the recommended course of treatment. Our Specialists can provide appropriate testing, treatment and follow-up to help manage the infection and protect your long-term health. If you are concerned about a previous exposure or have received a positive test result, please contact our Specialists for a confidential consultation and guidance on the next steps.
Tertiary Syphilis
Tertiary syphilis is a late manifestation of syphilis that can develop many years after the original infection if it has remained untreated. It is now uncommon in the UK, partly because syphilis is usually diagnosed and treated before reaching this stage.
Tertiary syphilis can affect different organs and systems of the body. Important manifestations include cardiovascular syphilis, which can damage the aorta and other parts of the cardiovascular system, and gummatous syphilis, which can cause inflammatory lesions known as gummas, most commonly affecting the skin and bones.
It is important to note that neurosyphilis, ocular syphilis and otosyphilis are not limited to tertiary syphilis. Syphilis can affect the brain, nervous system, eyes or ears at any stage of infection. These complications can sometimes occur during earlier stages of disease and require appropriate clinical assessment and treatment.
Treatment can eliminate the infection and help prevent further progression, but it cannot reliably reverse damage that has already occurred. This is why diagnosing and treating syphilis early is important.
If you are concerned about a previous exposure or have questions about your sexual health, our Specialists can provide confidential testing, assessment and appropriate treatment.
Congenital Syphilis
Congenital syphilis occurs when a pregnant person passes syphilis to their baby during pregnancy. It can have serious consequences, including miscarriage, stillbirth, premature birth and illness in the newborn. Syphilis can be transmitted to the baby at any stage of infection, although the risk is highest when the infection is recent and untreated.
Some babies with congenital syphilis may have no symptoms at birth. Without appropriate treatment, however, infection can cause serious health problems affecting the bones, liver, brain and nervous system, eyes and hearing.
In the UK, syphilis screening is routinely offered as part of antenatal care. Early diagnosis and appropriate treatment with penicillin during pregnancy can substantially reduce the risk of congenital syphilis and other adverse pregnancy outcomes.
If you are planning a pregnancy or are already pregnant and have concerns about a previous syphilis infection or possible exposure, it is important to speak with a healthcare professional. Our Specialists can provide confidential testing, assessment and guidance. If syphilis is diagnosed during pregnancy, appropriate treatment should be started promptly to reduce the risk to both the pregnant person and baby.
FAQs
Syphilis symptoms vary depending on the stage of the infection, and many people have no noticeable symptoms. When symptoms do occur, they can vary considerably and do not always follow a predictable sequence.
In the early stage, one of the most common symptoms is one or more small, painless sores (chancres) at the site where the infection entered the body, such as the genitals, anus, rectum or mouth. These usually appear around three weeks after exposure and may heal on their own, but the infection remains.
Secondary syphilis may develop weeks or months later and can cause:
• A non-itchy rash, often involving the palms of the hands and soles of the feet
• Fever
• Sore throat
• Swollen lymph nodes
• Headaches
• Tiredness
• Patchy hair loss or white patches in the mouth
Syphilis can then enter a latent stage, during which there are no noticeable symptoms. Without treatment, some people may develop complications affecting the brain, nervous system, heart, blood vessels, eyes, ears, bones or other organs. Neurological, ocular and otic complications can occur at any stage of syphilis and are not limited to late disease.
Because symptoms can be mild or absent, syphilis is usually diagnosed using blood tests, although direct detection of the bacterium from an active lesion, including molecular testing such as PCR where available, may also help diagnose early syphilis.
Yes. Many people with syphilis have no noticeable symptoms, particularly during the latent stage of the infection.
Early symptoms, such as a painless sore, can easily go unnoticed because they may occur inside the vagina, anus, rectum or mouth and often heal without treatment. This does not mean the infection has gone away.
Even without symptoms, syphilis can still be transmitted, particularly during stages when infectious mucocutaneous lesions are present. If left untreated, the infection can remain in the body and may cause complications in some people.
If you think you may have been exposed to syphilis or are sexually active with new or multiple partners, regular testing may be recommended depending on your individual circumstances. Syphilis is usually confirmed through blood tests, although direct detection from an active lesion may also be used in some circumstances.
Without treatment, syphilis can cause serious and sometimes permanent damage to the body.
Syphilis can affect different parts of the body at any stage of infection. Complications may involve the:
• Brain and nervous system
• Heart and blood vessels
• Eyes and ears
• Bones and other organs
Neurological, ocular and otic syphilis can occur at any stage and may lead to problems such as nerve damage, vision or hearing loss, or other neurological complications. Later manifestations can also include cardiovascular and gummatous disease.
If syphilis occurs during pregnancy, it can be passed to the baby and increase the risk of miscarriage, stillbirth, premature birth, or congenital syphilis.
Untreated syphilis is also associated with an increased risk of acquiring or transmitting HIV. Early diagnosis and appropriate antibiotic treatment can reduce the risk of complications and prevent further transmission.
The first symptoms of syphilis usually appear around three weeks after exposure, although they can develop approximately 10 to 90 days after infection.
The earliest sign is typically a painless sore (chancre) at the site where the infection entered the body.
Because symptoms may not appear immediately and some people have no noticeable symptoms, testing at the appropriate time is important. If you think you have been exposed to syphilis, speak to a healthcare professional about when testing should be performed and whether repeat testing may be needed.
Syphilis is caused by the bacterium Treponema pallidum. It is usually spread through direct contact with an infectious syphilis lesion during vaginal, anal, or oral sex.
Infectious lesions can occur on the genitals, anus, rectum, mouth, or other areas of the skin and mucous membranes. They may be painless or otherwise difficult to notice, so a person may not realise they have syphilis. Syphilis can also be passed from a pregnant person to their baby during pregnancy.
Anyone who is sexually active can get syphilis, but certain circumstances can increase the likelihood of exposure, including:
• Having sex without a condom or other barrier protection
• Having new or multiple sexual partners
• Having a sexual partner with syphilis
• Having sexual contact with people or in communities where syphilis is more common
• Having a history of another STI, which may indicate shared sexual exposure or other factors associated with increased risk
Because syphilis often causes no symptoms, regular STI testing may be recommended depending on your sexual history and individual circumstances. If you think you may have been exposed to syphilis, speak to a healthcare professional about testing and any further assessment you may need.
You can reduce your risk of getting syphilis by:
• Using condoms consistently during vaginal, anal, and oral sex. Condoms reduce the risk but do not provide complete protection because infectious lesions may occur on areas not covered by a condom
• Avoiding direct contact with sores, rashes, or other lesions that could be caused by syphilis
• Not sharing sex toys, or cleaning them thoroughly and using a new condom between users
• Having regular STI tests if you have new or multiple sexual partners or may have been exposed to an STI
• Discussing STI testing with a new partner before stopping condom use
If a sexual partner is diagnosed with syphilis, seek clinical assessment as well as testing, even if you do not have symptoms. Depending on the stage of your partner's infection and when the sexual contact occurred, preventive (epidemiological) treatment may be recommended without waiting for a test result.
Yes. Condoms greatly reduce the risk of syphilis but do not provide complete protection.
Syphilis spreads through direct contact with an infectious sore or rash. If the affected area is not covered by a condom, such as the scrotum, groin, anus, or mouth, transmission can still occur.
If you think you may have been exposed, arrange a syphilis test, even if you have no symptoms.
Yes, although it is uncommon.
Syphilis can be passed through kissing if one person has an infectious sore on or inside the mouth. Because these sores are often painless, they may go unnoticed.
If you have had close contact with someone who has syphilis or develop an unexplained sore in your mouth, consider getting tested.
No. Syphilis is not spread through sharing towels, clothing, cutlery, cups, toilet seats, baths, or swimming pools.
The infection is usually transmitted through direct contact with a syphilis sore during vaginal, anal, or oral sex. It can also be passed from a pregnant person to their baby during pregnancy.
If you are concerned about possible exposure, a blood test can confirm whether you have syphilis.
The risk of getting syphilis from a blood transfusion is extremely low.
Blood donations are routinely screened for infections, including syphilis, and the bacteria do not survive well in stored blood. As a result, transmission through blood transfusion is now exceptionally rare in countries with established blood screening programmes.
Syphilis is usually diagnosed with a blood test that detects antibodies produced in response to the infection.
If you have a visible sore, a healthcare professional may also take a swab to test for the bacteria directly. Your symptoms, sexual history, and the timing of any possible exposure also help guide the diagnosis.
Because it can take time for antibodies to develop, you may need a repeat blood test if you were tested soon after exposure.
Syphilis is most commonly diagnosed using blood tests. Testing usually involves a combination of different types of syphilis blood tests, which help clinicians determine whether someone has been infected and assess the infection in the context of their symptoms and medical history.
Depending on your symptoms and circumstances, testing may include:
• Treponemal blood tests, which detect antibodies directed against Treponema pallidum and usually remain positive for many years, often for life, after infection
• Non-treponemal blood tests, such as RPR or VDRL, which measure antibody levels and are useful alongside clinical history when assessing syphilis and monitoring response to treatment
• Direct detection from an infectious lesion, such as PCR where available, if a suitable sore or other lesion is present
No single blood test can reliably determine whether syphilis is simply “active” or “inactive.” Test results need to be interpreted alongside your symptoms, examination findings, previous treatment history and the timing of possible exposure.
If testing is performed soon after exposure, blood tests may not yet detect the infection. Depending on the timing and your individual circumstances, a repeat test may therefore be recommended.
An accurate diagnosis depends on several factors, including:
• The timing of your possible exposure
• Any symptoms you have, such as sores or a rash
• Your sexual history
• The results of blood tests or a swab, if a sore is present
Because antibodies may not be detectable immediately after infection, repeat testing may be needed if you are tested too early.
Yes. Syphilis is sometimes called the “great imitator” because its symptoms can resemble those of many other conditions.
For example, syphilis sores may be mistaken for herpes or minor skin injuries, while the rash can resemble eczema, psoriasis, or an allergic reaction. Flu-like symptoms may also be confused with common viral illnesses.
Because symptoms alone are not reliable for diagnosing syphilis, laboratory testing is needed to confirm the diagnosis. This may include blood tests and, where appropriate, direct testing of an infectious lesion.
Yes. Syphilis is usually diagnosed using blood tests, but other laboratory tests may also be used depending on your symptoms and clinical circumstances.
If you have a visible infectious lesion, a healthcare professional may collect a sample for direct testing, such as PCR where available.
If syphilis is suspected to have affected the brain, spinal cord, or other parts of the nervous system, a specialist may recommend additional investigations. A lumbar puncture and examination of cerebrospinal fluid (CSF) may be performed when clinically indicated following specialist assessment; it is not routinely required simply because neurological involvement is suspected.
The appropriate tests depend on your symptoms, examination findings, previous treatment history and other clinical factors. Your healthcare professional can advise which investigations are appropriate for you.
No. A physical examination can identify signs that suggest syphilis, but it cannot confirm the diagnosis.
Many syphilis symptoms resemble other conditions, and some people have no symptoms at all. A blood test, and sometimes a swab from a sore, is needed to confirm whether you have the infection.
No. You cannot reliably diagnose syphilis based on symptoms alone.
Some people have no symptoms, while others develop signs that can easily be mistaken for other conditions. Laboratory testing is needed to confirm the diagnosis.
Home or self-sampling tests that collect a blood sample can be used in some settings, but a reactive result requires appropriate confirmatory testing and clinical assessment. Depending on the type of test and your circumstances, further laboratory testing may be needed.
If you think you have been exposed to syphilis or develop symptoms, arrange testing and speak with a healthcare professional about the appropriate next steps.
The outlook for syphilis is generally very good when it is diagnosed and treated appropriately. Antibiotic treatment can cure the infection and substantially reduce the risk of developing complications.
If syphilis is left untreated, it can cause serious complications affecting the heart and blood vessels, brain and nervous system, eyes, ears, bones, and other organs. Neurological, ocular and otic complications can occur at any stage of infection. While appropriate treatment can stop the infection from progressing, it cannot reliably reverse damage that has already occurred.
After treatment, follow-up serology is used to assess the response to treatment. Quantitative non-treponemal tests, such as RPR or VDRL, are particularly useful for monitoring changes in antibody titres over time. Your healthcare professional will interpret your results alongside your symptoms, examination findings and previous treatment history.
Yes. Successfully treating syphilis does not make you immune to future infections.
You can become infected again if you are exposed to the bacteria through sexual contact. Using condoms, having regular STI testing, and ensuring partners are tested and treated if necessary can help reduce your risk.
Treatment cures the syphilis infection, so it does not return on its own. However, you can become infected again if you are exposed to syphilis in the future.
To reduce your risk of reinfection:
• Use condoms consistently during vaginal, anal, and oral sex. Condoms reduce the risk but do not provide complete protection because infectious lesions may occur on areas not covered by a condom
• Make sure current and relevant recent sexual partners are informed, assessed and treated if necessary
• Avoid sexual contact until at least two weeks after both you and your partner(s) have completed treatment, or until any infectious lesions have healed, whichever is later, in accordance with clinical advice
• Have regular STI tests if you have new or multiple sexual partners or may have been exposed to an STI
Because having syphilis once does not provide immunity, taking steps to reduce future exposure is important.
If you are diagnosed with syphilis, it is important to inform your current and relevant recent sexual partners so they can receive appropriate assessment and treatment.
The partners who need to be contacted and the period covered by partner notification depend on the stage of syphilis and when the infection was likely acquired. A sexual health professional can advise which partners should be contacted.
Some partners may be offered treatment based on their exposure to syphilis even if their initial test is negative, depending on the timing and circumstances of the exposure.
Many people with syphilis have no symptoms, so partners may not know they have been exposed. Identifying and treating people who may have been exposed can help prevent further transmission and reinfection.
If you are uncomfortable contacting partners yourself, many sexual health services can provide confidential partner-notification support and, where available, can contact partners without revealing your identity.
If you have syphilis, you can reduce the risk of passing it on by:
• Completing the full course of prescribed treatment
• Avoiding sexual contact until at least two weeks after both you and your partner(s) have completed treatment, or until any infectious lesions have healed, whichever is later, unless your healthcare professional gives you different advice
• Informing current and relevant recent sexual partners so they can receive appropriate assessment and treatment
• Using condoms during sex, while recognising that they do not provide complete protection because infectious lesions may occur outside the area covered by a condom
If you are pregnant, early testing and appropriate treatment are particularly important because syphilis can be passed to the baby during pregnancy. Timely treatment substantially reduces the risk of congenital syphilis and other adverse pregnancy outcomes.
Yes. Syphilis can be passed from a pregnant person to their baby during pregnancy, primarily through the placenta. Transmission during childbirth through contact with infectious lesions is also possible, but is less common. This is known as congenital syphilis.
Without appropriate treatment, syphilis during pregnancy can cause miscarriage, stillbirth, premature birth, or serious health problems in the baby.
Routine antenatal screening helps identify syphilis during pregnancy, and timely treatment with appropriate antibiotics substantially reduces the risk of transmission and adverse pregnancy outcomes.
If you are pregnant and have syphilis or think you may have been exposed, seek medical assessment promptly so that appropriate testing and treatment can be arranged.
Untreated syphilis during pregnancy can have serious consequences for both the parent and the baby.
Possible complications include:
• Miscarriage
• Stillbirth
• Premature birth
• Congenital syphilis, which can affect the baby's bones, hearing, vision, brain, and other organs
Early diagnosis and treatment with antibiotics are highly effective at preventing these complications.
Syphilis during pregnancy is relatively uncommon, but it remains an important condition to screen for because of the risks to the baby.
Routine antenatal blood tests are offered during pregnancy to detect syphilis, even if you have no symptoms. If the infection is found, prompt treatment is highly effective at protecting both you and your baby.
Penicillin is the recommended treatment for syphilis during pregnancy and is the only antibiotic with proven effectiveness for treating maternal syphilis and preventing congenital syphilis. The specific penicillin regimen depends on the stage and clinical circumstances of the infection.
Appropriate treatment during pregnancy substantially reduces the risk of passing syphilis to the baby and can help prevent serious complications. If you have a penicillin allergy, speak to your healthcare professional, as there is no proven alternative antibiotic for preventing congenital syphilis; penicillin desensitisation followed by penicillin treatment may be recommended.
After treatment, follow-up serology is used to assess the response to treatment. Your healthcare professional will interpret changes in your blood-test results alongside your stage of infection, treatment history and clinical circumstances.
The best way to reduce the risk is to attend all routine antenatal appointments and have the recommended syphilis screening test.
You can also reduce your risk by:
• Using condoms with new or untested sexual partners
• Getting tested promptly if you think you have been exposed to syphilis
• Ensuring any sexual partner is tested and treated if necessary
• Completing the full course of treatment if you are diagnosed
Early diagnosis and treatment are the most effective ways to protect both you and your baby.
Syphilis does not usually prevent breastfeeding, and syphilis is not transmitted through breast milk.
Breastfeeding is acceptable if there are no infectious syphilitic lesions on the breast or nipple. However, if an infectious sore or lesion is present on the breast or nipple, you should avoid breastfeeding from the affected breast and avoid giving expressed milk from that breast until the lesion has completely healed following appropriate treatment.
If only one breast is affected, you may be able to continue breastfeeding from the unaffected breast, provided there are no infectious lesions present.
If syphilis is diagnosed after giving birth, prompt assessment and treatment are important for your health and to reduce the risk of transmitting the infection through direct contact with infectious lesions.
Page last reviewed by Mrs. Magdalena Nowacka on 17 September 2026 for general guidance only. It is not intended to replace the advice of your clinician.