Dr. Christine Zink, MD, is a board-certified emergency medicine physician with expertise in global medicine. She utilizes 15 years of clinical experience in her medical writing.

Anju Goel, MD, MPH, is a board-certified physician who specializes in public health, communicable disease, diabetes, and health policy.

Syphilis is a sexually transmitted bacterial infection that evolves in four stages: primary, secondary, latent, and tertiary. The most advanced form is tertiary syphilis . Tertiary syphilis is a severe illness that develops 10–30 years after the initial infection. The disease damages many different internal organs.  

This article will discuss what syphilis is and how it is transmitted. It will focus on the symptoms of tertiary syphilis and will go into detail regarding the affected organ systems. Finally, the article will discuss treatment and how you can reduce your risk of infection. 

Jon Feingersh Photography Inc / Getty Images

There are four stages of infection with syphilis. A person will progress to the advanced stage if they do not receive appropriate antibiotic treatment in the initial stages of infection. However, progression typically occurs over decades.

A different set of symptoms defines each stage of syphilis. After acquiring the infection, the first set of symptoms begins in a few weeks. The second stage of syphilis symptoms starts a few months later. Advanced syphilis may not appear until decades later.

The organism, a bacterial spirochete called Treponema pallidum, is more likely to be transmitted to another person during the primary and secondary stages.

The defining features of each stage of syphilis are:

If a person goes untreated for syphilis during the initial years of illness, they can eventually develop tertiary syphilis. However, not everyone who remains untreated goes on to develop advanced disease.

People who have not been treated for syphilis develop tertiary syphilis. Historic data from the time before treatment was available estimated this progression happened in 15%–40% of people who were not treated.

The number of cases of syphilis in the United States reached a historic low in 2000 and 2001. However, infection rates are on the rise. In 2020, there were nearly 135,000 new syphilis cases.

The numbers for late latent syphilis and late syphilis with clinical manifestations (tertiary syphilis) in 2020 were 47,256, or 14.2 cases per 100,000 population.

Syphilis is an infection caused by the bacterium Treponema pallidum. The organism is transmitted through direct contact during sex and can be transmitted vertically (from a pregnant person to a fetus). It is more contagious during the early stages of infection. 

Syphilis is not transmitted through:

Syphilis is most often transmitted during the primary and secondary stages of the illness.

During sex, the bacterium passes from one person to another through open sores and lesions found in the genital and rectal areas. These lesions are called chancres or condyloma lata. Any interaction with these lesions, including through oral sex, can transmit the organism.

The most easily recognizable symptoms of syphilis are those that occur during the primary and secondary stages.

There are multiple skin manifestations, including a painless genital ulcer called a chancre, condyloma lata that are large, raised, gray lesions in the genital area, and a reddish-brown skin rash that can spread widely.

One of the hallmarks of this reddish-brown rash is that it involves the palms and soles of the feet. Most other rashes do not affect the palms and soles of the feet. These early dermatologic symptoms typically do not begin until several weeks or months after the initial infection.

Other secondary stage symptoms include:

Because tertiary syphilis is rare, it can be harder to spot. The infection affects multiple organ systems and can be fatal.

There is a wide range of neurological problems that tertiary syphilis leads to, including:

The syphilis bacterium can also invade the visual system and lead to:

Syphilis can also invade the hearing system and lead to:

Syphilis's effects on the heart include inflammation of the aorta, the major vessel leading away from the heart, dilation of the aorta, blockages in blood vessels of the heart, and inflammation of the heart itself. These problems can lead to heart attacks and problems with the heart valves.

This form of syphilis is rare, and cases have mainly been reported in people with human immunodeficiency virus (HIV). Gummas are ulcers with irregular borders that can be very large. They can occur anywhere on the skin, bones, or internal organs. On internal organs, gummas can be mistaken for a different type of mass lesion like cancer.

When a pregnant person has syphilis, there is a chance that the fetus will die in utero (be stillborn). Up to 40% of pregnancies in people with syphilis will end in stillbirth or the baby's death shortly after delivery.

Infants born to pregnant people with untreated syphilis will often have:

According to the World Health Organization (WHO), syphilis is the second leading cause of stillbirth.

Testing for syphilis occurs through a blood test. There are two types of tests: nontreponemal and treponemal. Both tests need to be performed to confirm a diagnosis.

These tests are generally cheap and are used for syphilis screening. They are also easy to use. However, false positive and false negative results can be seen, so further testing is often needed if there is a high suspicion of a person having syphilis.

These tests often confirm a diagnosis of syphilis. However, once these tests turn positive, they will remain positive for life, even if syphilis is treated. If a person has had a syphilis infection and been cured, but a repeat infection is suspected, a non-treponemal test may be used.

The treatment of choice for primary and secondary syphilis is penicillin G benzathine injected into a muscle (intramuscularly). It is given at a higher dose than used for other infections like strep throat. This dose also applies to pregnant people. The medication is delivered in a single dose.

When the antibiotic is given in this way, it stays in the body for up to 30 days. Most research reports a 90% to 100% cure rate.  Other antibiotics are available for people who are allergic to penicillin.

Later stages of syphilis, tertiary disease, require multiple doses of penicillin. The recommendation is to give a high dose three times at one-week intervals. 

People who develop certain organ damage from tertiary syphilis, such as neurosyphilis, ocular syphilis, and otosyphilis, should receive even higher doses of penicillin. The recommendation is to administer the higher dose every four hours intravenously.

Babies born to a person with syphilis should also receive penicillin. It may be given intravenously or by injection.

Since the advent of penicillin, deaths from syphilis are dramatically reduced. In the historic Oslo study from 1955, the death rate from untreated syphilis was 15.1% for men and 8.3% for women. Today, the treatment of syphilis is widely available, and most deaths from tertiary syphilis are prevented.

A study of death certificates in the United States found deaths from cardiovascular syphilis have been 1 to 6 per year from 1998 to 2015, and deaths from neurosyphilis were 16 to 34 per year. These are the most common causes of death from tertiary syphilis.

The way to reduce your risk of developing any sexually transmitted infection is to:

When beginning a new sexual relationship, it is helpful for both people to get tested for syphilis and other sexually transmitted infections (STIs). 

Finally, avoid contact with sores found in the genital and rectal areas.

People can become reinfected after being treated for syphilis. You do not become immune to syphilis after having it once, and there is no vaccine to prevent it. Using a condom during sex is essential to reduce the risk of reinfection.

Syphilis is an STI that evolves through four stages, the advanced stage (tertiary) being the most severe. People with tertiary syphilis can develop multiple organ damage to areas such as the brain, eyes, and heart.

There are a few different tests to diagnose syphilis, and they must be used together to confirm the diagnosis. All stages of syphilis are treated with penicillin. Advanced syphilis can be cured with high doses of the medicine. Still, the effects on organ systems are not reversible.

The best way to prevent syphilis is to reduce the number of sexual partners a person has and use condoms. 

Syphilis cases are rising again, and it can be a debilitating infection. It’s important to stay alert for symptoms. Get tested regularly for STIs, particularly if you have more than one partner. Use condoms. Syphilis is treatable. However, it’s not something to take lightly.

Syphilis produces a few different skin findings that depend on the stage of illness. Primary syphilis presents with a painless ulcer in the genital area.

Secondary syphilis can present with wartlike lesions in the genital area called condyloma lata and a reddish-brown rash that may spread. It can appear on the palms and soles of the feet.

Yes, syphilis is curable at all stages, but antibiotic dosing is different during later stages of the illness. However, the organ damage sustained from the infection is typically not reversible.

People with tertiary syphilis who develop damage to the heart, brain, or other organs can develop life-threatening disease.

The time it takes for syphilis to go away entirely depends on the stage of the illness. There are no set criteria that help establish when a person knows that a syphilis infection is completely cured.

The Centers for Disease Control and Prevention (CDC) recommends repeat syphilis testing to ensure a cure at six and 12 months after treatment for primary or secondary syphilis. Testing after treatment for latent syphilis should be done at six, 12, and 24 months.

Yes, syphilis can cause neurological effects. Neurosyphilis is often associated with personality changes, hallucinations, and forgetfulness.

Centers for Disease Control and Prevention. Syphilis - CDC fact sheet.

Peeling RW, Mabey D, Kamb ML, et al. Syphilis. Nat Rev Dis Primers. 2017;3:17073. doi:10.1038/nrdp.2017.73

Centers for Disease Control and Prevention. Table 19. Unknown duration or late syphilis* — reported cases and rates of reported cases by state/territory and region in alphabetical order, United States, 2016-2020.

Li X, Wang X, Wang Z, et al. Cardiovascular syphilis-associated acute myocardial infarction: A case report. Medicine (Baltimore). 2021;100(7):e24788. doi:10.1097/MD.0000000000024788

McVey M, Cameron W, MacPherson P. When infections collide--gummatous syphilis in an HIV-infected individual. Int J Infect Dis. 2010;14 Suppl 3:e283-6. doi:10.1016/j.ijid.2009.11.033

Centers for Disease Control and Prevention. Syphilis | effects and burden | pregnancy.

World Health Organization. Data on syphilis.

Clement ME, Okeke NL, Hicks CB. Treatment of syphilis: a systematic review. JAMA. 2014;312(18):1905-1917. doi:10.1001/jama.2014.13259

Centers for Disease Control and Prevention. Primary and secondary syphilis.

Centers for Disease Control and Prevention. Syphilis.

Centers for Disease Control and Prevention. Congenital syphilis.

Peterman TA, Kidd SE. Trends in deaths due to syphilis, United States, 1968-2015. Sex Transm Dis. 2019;46(1):37-40. doi:10.1097/OLQ.000000000000089

Centers for Disease Control and Prevention. Latent syphilis.

By Christine Zink, MD Dr. Christine Zink, MD, is a board-certified emergency medicine with expertise in the wilderness and global medicine. She completed her medical training at Weill Cornell Medical College and residency in emergency medicine at New York-Presbyterian Hospital. She utilizes 15-years of clinical experience in her medical writing.

Thank you, {{form.email}}, for signing up.

There was an error. Please try again.