Syphilis: Background, Pathophysiology, Etiology


Three genera of spirochetes cause human infection:

The particular spirochete responsible for syphilis is Treponema pallidum.

T pallidum is a fragile spiral bacterium 6-15 micrometers long by 0.25 micrometers in diameter. Its small size makes it invisible on light microscopy; therefore, it must be identified by its distinctive undulating movements on darkfield microscopy. It can survive only briefly outside of the body; thus, transmission almost always requires direct contact with the infectious lesion.

Syphilis is usually classified into 4 stages: primary, secondary, latent, and tertiary. It can be either acquired or congenital. That is, it can be transmitted either by intimate contact with infectious lesions (most common) or via blood transfusion (if blood has been collected during early syphilis), and it can also be transmitted transplacentally from an infected mother to her fetus.

In acquired syphilis, T pallidum rapidly penetrates intact mucous membranes or microscopic dermal abrasions and, within a few hours, enters the lymphatics and blood to produce systemic infection.

Incubation time from exposure to development of primary lesions, which occur at the primary site of inoculation, averages 3 weeks but can range from 10-90 days.

Studies in rabbits show that spirochetes can be found in the lymphatic system as early as 30 minutes after primary inoculation, suggesting that syphilis is a systemic disease from the outset.

The central nervous system (CNS) is invaded early in the infection; during the secondary stage, examinations demonstrate that more than 30% of patients have abnormal findings in the cerebrospinal fluid (CSF).

During the first 5-10 years after the onset of untreated primary infection, the disease principally involves the meninges and blood vessels, resulting in meningovascular neurosyphilis.

Later, the parenchyma of the brain and spinal cord are damaged, resulting in parenchymatous neurosyphilis. Go to Neurosyphilis for complete information on this topic.

Regardless of the stage of disease and location of lesions, histopathologic hallmarks of syphilis include endarteritis (which in some instances may be obliterative in nature) and a plasma cell–rich infiltrate.

Endarteritis is caused by the binding of spirochetes to endothelial cells, mediated by host fibronectin molecules bound to the surface of the spirochetes.

The resultant endarteritis can heal with scarring in some instances.

The syphilitic infiltrate reflects a delayed-type hypersensitivity response to T pallidum, and in certain individuals with tertiary syphilis, this response by sensitized T lymphocytes and macrophages results in gummatous ulcerations and necrosis. Antigens of T pallidum induce host production of treponemal antibodies and nonspecific reagin antibodies. Immunity to syphilis is incomplete.

For example, host humoral and cellular immune responses may prevent the formation of a primary lesion on subsequent infections with T pallidum, but they are insufficient to clear the organism. This may be because the outer sheath of the spirochete is lacking immunogenic molecules, or it may be because of down-regulation of helper T cells of the TH1 class. [1, 2]

Primary syphilis is characterized by the development of a painless chancre at the site of transmission after an incubation period of 3-6 weeks. The lesion has a punched-out base and rolled edges and is highly infectious.

Histologically, the chancre is characterized by mononuclear leukocytic infiltration, macrophages, and lymphocytes. The inflammatory reaction causes an obliterative endarteritis.

In this stage, the spirochete can be isolated from the surface of the ulceration or the overlying exudate of the chancre.

Whether treated or not, healing occurs within 3-12 weeks, with considerable residual fibrosis.

Secondary syphilis develops about 4-10 weeks after the appearance of the primary lesion. During this stage, the spirochetes multiply and spread throughout the body. Secondary syphilis lesions are quite variable in their manifestations. Systemic manifestations include malaise, fever, myalgias, arthralgias, lymphadenopathy, and rash.

Widespread mucocutaneous lesions are observed over the entire body and may involve the palms, soles, and oral mucosae.

Most often, the lesions are macular, discrete, reddish brown, and 5 mm or smaller in diameter; however, they can be pustular, annular, or scaling. Vesicular rash is typically absent. All such lesions contain treponemes.

Of these, wet mucous patches are the most contagious. Histologically, the inflammatory reaction is similar to but less intense than that of the primary chancre.

Other skin findings of secondary syphilis are condylomata lata and patchy alopecia. Condylomata lata are painless, highly infectious gray-white lesions that develop in warm, moist sites.

The alopecia is characterized by patchy hair loss of the scalp and facial hair, including the eyebrows. Patients with this finding have been referred to as having a “moth-eaten” appearance.

During secondary infection, the immune reaction is at its peak and antibody titers are high.

Latent syphilis is a stage at which the features of secondary syphilis have resolved, though patients remain seroreactive. Some patients experience recurrence of the infectious skin lesions of secondary syphilis during this period. About one third of untreated latent syphilis patients go on to develop tertiary syphilis, whereas the rest remain asymptomatic.

Currently, tertiary syphilis disease is rare. When it does occur, it mainly affects the cardiovascular system (80-85%) and the CNS (5-10%), developing over months to years and involving slow inflammatory damage to tissues. The 3 general categories of tertiary syphilis are gummatous syphilis (also called late benign), cardiovascular syphilis, and neurosyphilis.

Gummatous syphilis is characterized by granulomatous lesions, called gummas, which are characterized by a center of necrotic tissue with a rubbery texture. Gummas principally form in the liver, bones, and testes but may affect any organ.

Histological examination shows palisaded macrophages and fibroblasts, as well as plasma cells surrounding the margins. Gummas may break down and form ulcers, eventually becoming fibrotic.

Treponemes are rarely visualized or recovered from these lesions.

Cardiovascular syphilis occurs at least 10 years after primary infection. The most common manifestation is aneurysm formation in the ascending aorta, caused by chronic inflammatory destruction of the vasa vasorum, the penetrating vessels that nourish the walls of large arteries. Aortic valve insufficiency may result.

Neurosyphilis has several forms. If the spirochete invades the CNS, syphilitic meningitis results. Syphilitic meningitis is an early manifestation, usually occurring within 6 months of the primary infection. CSF shows high protein, low glucose, high lymphocyte count, and positive syphilis serology.

Meningovascular syphilis occurs as a result of damage to the blood vessels of the meninges, brain, and spinal cord, leading to infarctions causing a wide spectrum of neurologic impairments.

Parenchymal neurosyphilis includes tabes dorsalis and general paresis. Tabes dorsalis develops as the posterior columns and dorsal roots of the spinal cord are damaged. Posterior column impairment results in impaired vibration and proprioceptive sensation, leading to a wide-based gait.

Disruption of the dorsal roots leads to loss of pain and temperature sensation and areflexia. Damage to the cortical regions of the brain leads to general paresis, formerly called “general paresis of the insane,” which mimics other forms of dementia. Impairment of memory and speech, personality changes, irritability, and psychotic symptoms develop and may advance to progressive dementia.

The Argyll-Robertson pupil, a pupil that does not react to light but does constrict during accommodation, may be seen in tabes dorsalis and general paresis. The precise location of the lesion causing this phenomenon is unknown.

Congenital syphilis, discussed briefly here, is a veritable potpourri of antiquated medical terminology.

The treponemes readily cross the placental barrier and infect the fetus, causing a high rate of spontaneous abortion and stillbirth.

Within the first 2 years of life, symptoms are similar to severe adult secondary syphilis with widespread condylomata lata and rash. “Snuffles” describes the mucopurulent rhinitis caused by involvement of the nasal mucosae.

Later manifestations of congenital syphilis include bone and teeth deformities, such as “saddle nose” (due to destruction of the nasal septum), “saber shins” (due to inflammation and bowing of the tibia), “Clutton’s joints” (due to inflammation of the knee joints), “Hutchinson’s teeth” (in which the upper incisors are widely spaced and notched), and “mulberry molars” (in which the molars have too many cusps).

Tabes dorsalis and general paresis may develop as in adults, with 8th cranial nerve deafness and optic nerve atrophy as well as a variety of other ophthalmologic involvement leading to blindness being additional features.

From 2012-2014, the number of congenital syphilis cases in the United States increased from 334 to 458. This appears to be associated with an increase in the rate of primary and secondary syphilis among women. [3]

Go to Pediatric Syphilis for complete information on this topic.




Syphilis is a highly contagious disease that’s mostly spread through sexual activity, including oral and anal sex. The infected person often doesn’t know that they have the disease and passes it on to their sexual partner.

Syphilis was once a major public health threat. It can cause serious long-term problems such as arthritis, brain damage, and blindness. There wasn’t an effective treatment until the late 1940s, when the antibiotic penicillin was developed.

According to the CDC, the rate of new cases of syphilis plummeted in the 1990s. In 2000, it reached an all-time low since reporting began in 1941. But the disease has been on the increase ever since.

Syphilis is caused by the bacteria Treponema pallidum. These bacteria can enter your body through cuts on your skin or through your mucous membranes.

Syphilis can’t be spread by toilet seats, doorknobs, swimming pools, hot tubs, bathtubs, shared clothing, or eating utensils.

You’re at higher risk of getting syphilis if you:

  • Have unprotected sex
  • Have multiple sex partners
  • Have HIV
  • Are a man who has sex with men

Syphilis infection has three stages:

Early or primary syphilis. People with primary syphilis get one or more sores called chancres. They’re usually small painless ulcers.

They happen on your genitals, on your anus or rectum, or in or around your mouth between 10 and 90 days (3 weeks on average) after you’re exposed to the disease.

Even if you don’t treat them, they heal without a scar within 6 weeks. But treatment will keep your disease from moving to the next stage.

Secondary syphilis. This stage begins 6 weeks to 6 months after you’re exposed. It may last 1 to 3 months. People with secondary syphilis usually get a rosy “copper penny” rash on the palms of their hands and soles of their feet.

They may also have different rashes on other parts of their body. These may look rashes caused by other diseases. People may have moist wart- lesions in their groin, white patches on the inside of their mouth, swollen lymph glands, fever, hair loss, and weight loss.

with primary syphilis, symptoms of secondary syphilis will get better without treatment.

Tertiary syphilis. If the infection isn't treated, it may move on to a stage marked by severe problems with your heart, brain, and nerves. You could become paralyzed, blind, or deaf, or get dementia or impotence. It can even be deadly.

Other types of syphilis include:

Latent syphilis. The infection doesn’t have any noticeable symptoms but is still in your body.

Congenital syphilis. A pregnant woman with the disease can spread it to her baby. It can harm the baby and even cause death.

Neurosyphilis. The infection can spread to your brain or spinal cord. You might get headaches, dementia, or numbness or become paralyzed. You could have a hard time controlling your muscles.

If you don’t get treatment, syphilis can have complications all over your body:

  • Small bumps. Bumps called gummas can grow on your skin, bones, or organs. They can destroy the tissue around them.
  • Nervous system problems. Syphilis can cause problems headaches, meningitis, brain damage, paralysis, or hearing and vision loss.
  • Cardiovascular problems. The disease can damage your heart valves or cause bulging blood vessels (aneurysms) or an inflamed aorta (aortitis).
  • HIV. Syphilis can increase your chance of getting HIV.

The CDC says women should be tested for syphilis at least once during pregnancy. It’s best if they’re tested at their first prenatal visit. Depending on how long a pregnant woman has had syphilis, she has a high chance of stillbirth (birth of an infant who has died before delivery) or of giving birth to a baby who dies shortly after birth.

An infected baby may be born without symptoms but could have them within a few weeks if the disease isn’t treated right away. These signs and symptoms can be very serious. Untreated babies may have delays in their development, have seizures, or die.

Your doctor will need to do a physical exam. They might give you tests including:

  • Blood tests. A quick test at your doctor’s office or a public health clinic can diagnose syphilis.
  • Cerebrospinal fluid tests. If your doctor thinks you might have neurosyphilis, they’ll test fluid taken from around your spinal cord.
  • Darkfield microscopy. Syphilis bacteria are visible through a microscope in fluid taken from a skin sore or lymph node.

Syphilis is curable with quick diagnosis and treatment. But if it’s treated too late, it can permanently damage your heart and brain even after the infection is gone.

If you've had syphilis for less than a year, one dose of penicillin is usually enough to kill the infection. If you’re allergic to penicillin, you might get another antibiotic instead, doxycycline. If you’re in a later stage of the disease, you’ll need more doses.

If you’re pregnant and allergic to penicillin, your doctor will probably have you undergo a process called desensitization, which will let you take the drug safely.

Don’t have sexual contact until the infection is completely gone. Your sexual partners should also be tested and, if necessary, treated.

Some people with syphilis have an immune system reaction called a Jarisch-Herxheimer reaction several hours after their first treatment. This might include fever, chills, headache, upset stomach, rash, or joint and muscle pain. These problems usually go away within 24 hours.

You can get syphilis again after treatment kills the infection. To reduce your risk of syphilis infection:

  • Don’t have intimate contact with someone if you know they’re infected.
  • If you don’t know whether a sexual partner is infected, use a condom every time you have sex.



Mayo Clinic: “Syphilis.”

American College of Obstetricians and Gynecologists: “Chlamydia, Gonorrhea, and Syphilis.”

Icahn School of Medicine at Mount Sinai: “Syphilis — primary.”

Minnesota Department of Health: “About Syphilis.”

BMJ: “Syphilis.”

Merck Manual Consumer Version: “Syphilis.”

© 2019 WebMD, LLC. All rights reserved. Syphilis Symptoms


What Is Syphilis in Women? Pictures, Symptoms, Treatment & Signs


A sexually transmitted disease caused by Treponema pallidum, a microscopic organism called a spirochete. This worm-, spiral-shaped organism infects people by burrowing into the moist mucous membranes of the mouth or genitals. From there, the spirochete produces a non-painful ulcer known as a chancre.

Click here to see a picture of syphilis »

What are the signs and symptoms of syphilis?

Syphilis infection, when untreated, progresses through different clinical stages with characteristic signs and symptoms. After the first infection, symptoms typically develop at around 21 days after the infection, but they may appear anywhere from 10 to 90 days following infection.

Primary syphilis

The first, or primary, stage of syphilis is characterized by the formation of a painless ulcer known as a chancre. This sore develops at the site of infection and is usually solitary. A chancre is usually firm and round in shape. Sometimes, multiple chancres may be present.

The chancre contains the infectious bacteria and while the sore is present, the condition is highly contagious. Any contact with the chancre can spread the infection. If the chancre is located in the mouth, for example, even kissing can spread the disease. The chancre lasts for about 3 to 6 weeks and typically then goes away on its own.

The use of condoms may also not prevent spread of the illness if the chancre is located on an area of the body not covered by the condom.

Secondary syphilis

If primary syphilis is left untreated, secondary syphilis may develop. This stage of the illness usually occurs weeks to months after the primary stage. Secondary syphilis is characterized by a skin rash that typically does not itch and may easily be mistaken for rashes caused by other illnesses.

It may appear on almost any part of the body, including sores inside the mouth, vagina, or anus. The rash of secondary syphilis is often found on the palms of the hands and the soles of the feet, which is unusual for most rashes. In some people, the rash may be mild and not noticed.

Raised gray or whitish patches of skin, known as condyloma lata, may also develop, particularly in warm and moist areas of the body such as the armpits, mouth, or groin.

In secondary syphilis, the infection has spread throughout the body, so other symptoms may be associated with the skin manifestations.

Fever, enlarged lymph nodes, fatigue, weight loss, hair loss, headaches, and muscle aches have all been reported in the secondary stage of syphilis.

These symptoms will eventually subside, but if this secondary stage of the infection is not treated, the infection can progress to tertiary syphilis.

Tertiary syphilis

After the symptoms of secondary syphilis go away, the infection remains latent in the body if untreated. About 15% of infected and untreated people will go on to develop the third stage of syphilis, which can occur as much as 10 to 20 years after the initial infection. Tertiary syphilis is characterized by damage to any number of organ systems and can even be fatal.

Tertiary syphilis can cause damage to the brain, nerves, eyes, heart, blood vessels, liver, bones, and joints. Symptoms that can result from the late stage of syphilis include problems with movement, gradual loss of sight, dementia, paralysis, and numbness.

Neurosyphilis is the term used to refer to the involvement of the central nervous system and alterations in neurologic function.

Neonatal or congenital syphilis

Untreated syphilis in a pregnant women results in death of the fetus in up to 40% of infected pregnant women (stillbirth or death shortly after birth), so all pregnant women should be tested for syphilis at their first prenatal visit.

The screening test is usually repeated in the third trimester of pregnancy as well. If infected babies are born and survive, they are at risk for serious problems including seizures and developmental delays.

Fortunately, syphilis in pregnancy is treatable.


Syphilis – CDC Fact Sheet


Syphilis is a sexually transmitted infection that can cause serious health problems if it is not treated. Syphilis is divided into stages (primary, secondary, latent, and tertiary). There are different signs and symptoms associated with each stage.

How is syphilis spread?

You can get syphilis by direct contact with a syphilis sore during vaginal, anal, or oral sex. You can find sores on or around the penis, vagina, or anus, or in the rectum, on the lips, or in the mouth. Syphilis can spread from an infected mother to her unborn baby.

Example of a primary syphilis sore.

What does syphilis look ?

Syphilis is divided into stages (primary, secondary, latent, and tertiary), with different signs and symptoms associated with each stage. A person with primary syphilis generally has a sore or sores at the original site of infection.

These sores usually occur on or around the genitals, around the anus or in the rectum, or in or around the mouth. These sores are usually (but not always) firm, round, and painless. Symptoms of secondary syphilis include skin rash, swollen lymph nodes, and fever.

The signs and symptoms of primary and secondary syphilis can be mild, and they might not be noticed. During the latent stage, there are no signs or symptoms. Tertiary syphilis is associated with severe medical problems.

 A doctor can usually diagnose tertiary syphilis with the help of multiple tests. It can affect the heart, brain, and other organs of the body.

How can I reduce my risk of getting syphilis?

The only way to avoid STDs is to not have vaginal, anal, or oral sex.

If you are sexually active, you can do the following things to lower your chances of getting syphilis:

  • Being in a long-term mutually monogamous relationship with a partner who has been tested for syphilis and does not have syphilis;
  • Using latex condoms the right way every time you have sex. Condoms prevent transmission of syphilis by preventing contact with a sore. Sometimes sores occur in areas not covered by a condom. Contact with these sores can still transmit syphilis.

Am I at risk for syphilis?

Any sexually active person can get syphilis through unprotected vaginal, anal, or oral sex. Have an honest and open talk with your health care provider and ask whether you should be tested for syphilis or other STDs.

  • All pregnant women should be tested for syphilis at their first prenatal visit.
  • You should get tested regularly for syphilis if you are sexually active and

I’m pregnant. How does syphilis affect my baby?

If you are pregnant and have syphilis, you can give the infection to your unborn baby. Having syphilis can lead to a low birth weight baby.

It can also make it more ly you will deliver your baby too early or stillborn (a baby born dead). To protect your baby, you should be tested for syphilis at least once during your pregnancy.

Receive immediate treatment if you test positive.

An infected baby may be born without signs or symptoms of disease. However, if not treated immediately, the baby may develop serious problems within a few weeks. Untreated babies can have health problems such as cataracts, deafness, or seizures, and can die.

Secondary rash from syphilis on palms of hands.

Primary Stage

During the first (primary) stage of syphilis, you may notice a single sore or multiple sores. The sore is the location where syphilis entered your body. Sores are usually (but not always) firm, round, and painless.

Because the sore is painless, it can easily go unnoticed. The sore usually lasts 3 to 6 weeks and heals regardless of whether or not you receive treatment. Even after the sore goes away, you must still receive treatment.

This will stop your infection from moving to the secondary stage.

Secondary Stage

During the secondary stage, you may have skin rashes and/or mucous membrane lesions. Mucous membrane lesions are sores in your mouth, vagina, or anus. This stage usually starts with a rash on one or more areas of your body.

The rash can show up when your primary sore is healing or several weeks after the sore has healed. The rash can look rough, red, or reddish brown spots on the palms of your hands and/or the bottoms of your feet. The rash usually won’t itch and it is sometimes so faint that you won’t notice it.

Other symptoms you may have can include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue (feeling very tired). The symptoms from this stage will go away whether or not you receive treatment.

Without the right treatment, your infection will move to the latent and possibly tertiary stages of syphilis.

Secondary rash from syphilis on torso.

Latent Stage

The latent stage of syphilis is a period of time when there are no visible signs or symptoms of syphilis. If you do not receive treatment, you can continue to have syphilis in your body for years without any signs or symptoms.

Tertiary Stage

Most people with untreated syphilis do not develop tertiary syphilis. However, when it does happen it can affect many different organ systems.

These include the heart and blood vessels, and the brain and nervous system. Tertiary syphilis is very serious and would occur 10–30 years after your infection began.

 In tertiary syphilis, the disease damages your internal organs and can result in death.

Neurosyphilis and Ocular Syphilis

Without treatment, syphilis can spread to the brain and nervous system (neurosyphilis) or to the eye (ocular syphilis). This can happen during any of the stages described above.

Symptoms of neurosyphilis include

  • severe headache;
  • difficulty coordinating muscle movements;
  • paralysis (not able to move certain parts of your body);
  • numbness; and
  • dementia (mental disorder).

Symptoms of ocular syphilis include changes in your vision and even blindness.

Darkfield micrograph of Treponema pallidum.

How will I or my doctor know if I have syphilis?

Most of the time, a blood test is used to test for syphilis. Some health care providers will diagnose syphilis by testing fluid from a syphilis sore.

Can syphilis be cured?

Yes, syphilis can be cured with the right antibiotics from your health care provider. However, treatment might not undo any damage that the infection has already done.

I’ve been treated. Can I get syphilis again?

Having syphilis once does not protect you from getting it again. Even after you’ve been successfully treated, you can still be re-infected. Only laboratory tests can confirm whether you have syphilis. Follow-up testing by your health care provider is recommended to make sure that your treatment was successful.

It may not be obvious that a sex partner has syphilis. This is because syphilis sores can be hidden in the vagina, anus, under the foreskin of the penis, or in the mouth. Unless you know that your sex partner(s) has been tested and treated, you may be at risk of getting syphilis again from an infected sex partner.

Where can I get more information?

Syphilis and MSM – Fact Sheet
Congenital Syphilis – Fact Sheet
STDs during Pregnancy – Fact Sheet

STD information and referrals to STD ClinicsCDC-INFO1-800-CDC-INFO (800-232-4636)TTY: 1-888-232-6348

In English, en Español


Syphilis: Symptoms, treatment, is it curable, and diagnosis


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Syphilis is a sexually transmitted bacterial infection. It is treatable in the early stages, but without treatment, it can lead to disability, neurological disorders, and even death.

The bacterium Treponema pallidum (T. pallidum) causes syphilis. There are four stages of the disease: primary, secondary, latent, and tertiary.

In 2018, the Centers for Disease Control and Prevention (CDC) noted that 64% of syphilis presentations involved men who have sex with men. However, the number of cases in heterosexual men and women is also increasing.

Syphilis is treatable with antibiotics, especially in the early stages. It does not resolve without treatment.

In this article, we explain the different stages of syphilis and whether it is curable, as well as how to recognize and treat it.

Share on PinterestFever is a possible secondary symptom of syphilis.

Syphilis is an infection that develops due to T. pallidum bacteria. These bacteria can spread between people through direct contact with a syphilitic sore.

These sores may develop on the skin or mucous membranes of the vagina, anus, rectum, lips, or mouth.

Syphilis is most ly to spread during oral, anal, or vaginal sexual activity. People rarely pass the bacteria on through kissing.

The first sign is a painless sore on either the genitals, rectum, mouth, or another part of the skin. Some people do not notice the sore, as it does not cause pain.

These sores resolve on their own. However, if a person does not receive treatment, the bacteria remain in the body. They can remain dormant in the body for decades before reactivating and damaging organs, including the brain.

Doctors categorize the stage of syphilis as either primary, secondary, latent, or tertiary. A variety of symptoms define each stage.

The disease can be contagious during the primary and secondary stages and, occasionally, the early latent phase. Tertiary syphilis is not contagious, but it has the most severe symptoms.

Primary symptoms

The symptoms of primary syphilis include one or more painless, firm, and round syphilitic sores, or chancres. These appear 10 days to 3 months after the bacteria enter the body.

Chancres resolve within 2–6 weeks. However, without treatment, the disease may remain in the body and progress to the next phase.

Secondary symptoms

Secondary syphilis symptoms include:

  • sores that resemble oral, anal, and genital warts
  • a nonitchy, rough, red or red-brown rash that starts on the trunk and spreads to the entire body, including the palms and soles
  • muscle aches
  • fever
  • a sore throat
  • swollen lymph nodes
  • patchy hair loss
  • headaches
  • unexplained weight loss
  • fatigue

These symptoms may resolve a few weeks after they first appear. They might also return several times over a longer period.

Without treatment, secondary syphilis can progress to the latent and tertiary stages.

Read more about secondary syphilis.

Latent syphilis

The latent phase can last for several years. During this time, the body will harbor the disease without symptoms.

However, the T. pallidum bacteria remain dormant in the body, and there is always a risk of recurrence. Doctors still recommend treating syphilis at this stage, even if symptoms do not occur.

After the latent phase, tertiary syphilis may develop.

Tertiary syphilis, or late syphilis

Tertiary syphilis can occur 10–30 years after the onset of the infection, usually after a period of latency during which there are no symptoms.

At this stage, syphilis damages the following organs and systems:

  • heart
  • blood vessels
  • liver
  • bones
  • joints

Gummas may also develop. These are soft tissue swellings that can occur anywhere on the body.

Organ damage means that tertiary syphilis can often lead to death. Treating syphilis before it reaches this stage is, therefore, critical.


Neurosyphilis is a condition that develops when T. pallidum bacteria have spread to the nervous system. It often has links to latent and tertiary syphilis. However, it can occur at any time after the primary stage.

A person with neurosyphilis may be asymptomatic for a long time. Alternatively, symptoms might develop gradually.

Symptoms include:

  • dementia or altered mental status
  • abnormal gait
  • numbness in the extremities
  • problems with concentration
  • confusion
  • headache or seizures
  • vision problems or vision loss
  • weakness

Congenital syphilis

Congenital syphilis is severe and frequently life threatening. T. pallidum bacteria can transfer from a pregnant woman to a fetus through the placenta and during the birth process.

Data suggest that without screening and treatment, about 70% of women with syphilis will have an adverse outcome in pregnancy.

Adverse outcomes include early fetal or neonatal death, preterm birth or low birth weight, and infection in infants.

Symptoms in newborns include:

  • saddle nose, in which the bridge of the nose is missing
  • fever
  • difficulty gaining weight
  • a rash of the genitals, anus, and mouth
  • small blisters on the hands and feet that change to a copper colored rash, which may be bumpy or flat, and spread to the face
  • watery nasal fluid

Older infants and young children may experience:

  • Hutchinson teeth, or abnormal, peg shaped teeth
  • bone pain
  • vision loss
  • hearing loss
  • joint swelling
  • saber shins, a bone problem in the lower legs
  • scarring of the skin around the genitals, anus, and mouth
  • gray patches around the outer vagina and anus

In 2015, the World Health Organization (WHO) confirmed Cuba as the first country in the world to have entirely eradicated congenital syphilis.

Learn how to recognize different STDs here.

Anyone who is worried that they might have syphilis or another sexually transmitted infection (STI) should speak to a doctor as soon as possible, as prompt treatment can cure it.

Early treatment with penicillin is important, as the disease can lead to life threatening consequences in the long term.

At a later stage, syphilis remains curable. However, a person may require a longer course of penicillin.

If nerve or organ damage occurs during the later stages of syphilis, treatment will not repair it. Treatment can, however, prevent further damage by clearing the bacteria from a person’s body.

Treatment for syphilis can be successful, particularly in the early stages.

The treatment strategy will depend on the symptoms and how long a person has harbored the bacteria. However, during the primary, secondary, or tertiary stage, people with syphilis will typically receive an intramuscular injection of penicillin G benzathine.

Tertiary syphilis will require multiple injections at weekly intervals.

Neurosyphilis requires intravenous (IV) penicillin every 4 hours for 2 weeks to remove the bacteria from the central nervous system.

Curing the infection will prevent further damage to the body, and safe sexual practices can resume. However, treatment cannot undo any damage that has already occurred.

People with a penicillin allergy can sometimes use an alternative medication in the early stages. However, during pregnancy and in the tertiary stages, anyone with an allergy will undergo penicillin desensitization to allow for safe treatment.

Following delivery, newborn infants with syphilis should undergo antibiotic treatment.

Chills, fever, nausea, achy pain, and a headache may occur on the first day of treatment. Doctors refer to these symptoms as a Jarisch-Herxheimer reaction. It does not indicate that a person should stop treatment.

People with syphilis must avoid sexual contact until they have completed all treatment and received blood test results confirming that the disease has resolved.

It may take several months for blood tests to show that syphilis has reduced to an appropriate level. Low enough levels confirm adequate treatment.

A doctor will carry out a physical examination and ask about a person’s sexual history before carrying out clinical tests to confirm syphilis.

Tests include:

  • Blood tests: These can detect a current or past infection, as antibodies to the syphilis bacteria will be present for many years.
  • Bodily fluid: A doctor can evaluate fluid from a chancre during the primary or secondary stage.
  • Cerebrospinal fluid: A doctor may collect this fluid through a spinal tap and examine it to monitor the disease’s effects on the nervous system.

If a person receives a diagnosis of syphilis, they must notify any sexual partners. Their partners should also undergo testing.

Local services are available to notify sexual partners of their potential exposure to syphilis, enable testing and, if necessary, administer treatment.

Healthcare professionals will also recommend testing for HIV.

When to receive testing

Many people with an STI will not be aware of it. Therefore, it is a good idea to talk to a doctor or request a test in the following situations:

  • after having unprotected sex
  • having a new sex partner
  • having multiple sex partners
  • a sexual partner receiving a diagnosis of syphilis
  • a man having sex with different men
  • symptoms of syphilis being present

Syphilis develops when T. pallidum transfer from one person to another during sexual activity.

The infection can pass from a woman to a fetus during pregnancy or to an infant during delivery. This type is called congenital syphilis.

Syphilis cannot spread through shared contact with objects, such as doorknobs, eating utensils, and toilet seats.

Sexually active people are at risk of contracting syphilis. Those most at risk include:

  • people who have unprotected sex
  • men who have sex with men
  • people living with HIV
  • individuals with more than one sexual partner

Syphilitic sores also increase the risk of contracting HIV.

Preventive measures to decrease the risk of syphilis include:

  • abstaining from sex
  • maintaining long term mutual monogamy with a partner who does not have syphilis
  • using a condom, although these only protect against genital sores and not those that develop elsewhere on the body
  • using a dental dam, or plastic square, during oral sex
  • avoiding sharing sex toys
  • refraining from alcohol and drugs that could potentially lead to unsafe sexual practices

Having syphilis once does not mean that a person has protection from it going forward. Even after treatment has successfully removed syphilis from a person’s body, it is possible for them to contract it again.

Many different types of condom are available to buy online. Dental dams are also available for purchase online.

Is syphilis the most dangerous STI?

While syphilis can indeed cause dangerous complications, it is important to remember that many STIs can lead to potentially serious health consequences if you do not receive treatment. For example:

  • STIs such as gonorrhea or chlamydia can lead to problems getting pregnant.
  • Human papillomavirus (HPV), the virus that causes genital warts, can lead to the development of cervical cancer.
  • HIV can be fatal without treatment. Additionally, having an untreated STI can increase your risk of getting HIV.

Practicing safe sex and knowing your STI status are important ways to help prevent the spread of these infections. If you have a new sexual partner, have had multiple sexual partners, or are concerned that you may have an STI, be sure to undergo testing.

Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

  • Men's Health
  • Sexual Health / STDs
  • Women's Health / Gynecology


Syphilis Picture Image on


Syphilis: A sexually transmitted disease caused by Treponema pallidum, a microscopic organism called a spirochete. This worm-, spiral-shaped organism infects people by burrowing into the moist mucous membranes of the mouth or genitals. From there, the spirochete produces a non-painful ulcer known as a chancre. There are three stages of syphilis:

  • The first (primary) stage: This involves the formation of the chancre. At this stage, syphilis is highly contagious. The primary stage can last one to five weeks. The disease can be transmitted from any contact with one of the ulcers, which are teeming with spirochetes.

    If the ulcer is outside of the vagina or on the scrotum, the use of condoms may not help in preventing transmission. wise, if the ulcer is in the mouth, merely kissing the infected individual can spread syphilis. Even without treatment, the early infection resolves on its own in most women.

  • The second (secondary) stage: However, 25 percent of cases will proceed to the secondary stage of syphilis, which lasts four to six weeks. This phase can include hair loss; a sore throat; white patches in the nose, mouth, and vagina; fever; headaches; and a skin rash.

    There can be lesions on the genitals that look genital warts, but are caused by spirochetes rather than the wart virus. These wart- lesions, as well as the skin rash, are highly contagious. The rash can occur on the palms of the hands, and the infection can be transmitted by casual contact.

  • The third (tertiary) stage: This final stage of the disease involves the brain and heart, and is usually no longer contagious. At this point, however, the infection can cause extensive damage to the internal organs and the brain, and can lead to death.

Diagnosis is by blood test, either the rapid plasma reagin (RPR) or Venereal Disease Research Laboratory (VDRL) test. Treatment is with antibiotics.

Syphilis remains a major health problem. About 12 million new cases of syphilis occur every year.

More than 90% of them are in developing nations where congenital syphilis remains a leading cause of stillbirths and newborn deaths.

In North America and Western Europe, syphilis is disproportionately common and rising among men who have sex with men and among persons who use cocaine or other illicit drugs.

The name “syphilis” was coined by Hieronymus Fracastorius (Girolamo Fracastoro). Fracastorius was a true Renaissance man; he wrote on the temperature of wines, the rise of the Nile, poetry, the mind, and the soul; he was an astronomer, geographer, botanist, mathematician, philosopher and, last but not least in the present context, a physician.

In 1530 he published the poem “Syphilis sive morbus gallicus” (Syphilis or the French Disease) in which the name of the disease first appeared.

Perhaps more importantly, Fracastorius went on in 1546 to write “On Contagion” (“De contagione et contagiosis morbis et curatione”), the first known discussion of the phenomenon of contagious infection: a landmark in the history of infectious disease.

Image Source: Science Source/Photo Researchers, Fitzpatrick's Color Atlas & Synopsis of Clinical Dermatology

Text: MedTerms™ Medical Dictionary by MedicineNet, Inc.