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What is syphilis?

Syphilis is a type of sexually transmitted disease (STD) caused by an infection of the bacterium Treponema pallidum. Syphilis can also be spread to a fetus by an infected mother during pregnancy. A simple blood test can check for this bacterial infection.

Syphilis can be prevented and is easily treated in its early stages. Despite this, its transmission both through sexual contact and during pregnancy has been on the rise in the United States in recent years, according to the Centers for Disease Control and Prevention  (Source: CDC).

Any person of any age who engages in sexual activity can contract and pass on syphilis. This includes heterosexual, homosexual, and bisexual men and women. The more sexual partners a person has, the greater the risk of catching a syphilis infection.

Left untreated, a syphilis infection can stay in the body for years and progress to serious or life-threatening complications, such as dementia, aortic aneurysm, and stillbirth in a pregnant woman. Using safer sex practices, seeking regular medical care, and seeking early, regular prenatal care can help reduce the risk of serious complications of syphilis.

What are the symptoms of syphilis?

Syphilis is an infection that can stay in the body for years if not recognized and treated promptly. There are three stages of syphilis, and each stage has distinct symptoms.

Symptoms of primary syphilis

Primary syphilis is the first stage of syphilis. Symptoms include:

  • A painless lesion called a chancre develops any time from 10 days to three months after exposure.

  • The chancre generally appears on the genital area but can also form on the lips, tongue or rectum if these areas have been exposed to a syphilis chancre on another person during oral or anal sexual contact. A chancre in the vagina, mouth or rectum is generally not easily seen.

  • The chancre heals in one to five weeks.

Symptoms of secondary syphilis

If left untreated, primary syphilis progresses to a second stage called secondary syphilis. In this stage, the bacteria that cause syphilis spread throughout the body and cause additional symptoms. Symptoms begin to appear about six weeks after the chancre has resolved and include:

Symptoms of tertiary syphilis

The third and final stage of syphilis is called tertiary or late-stage syphilis, which develops from untreated secondary syphilis. When untreated secondary syphilis symptoms disappear, the infection still continues in the body.

Symptoms of tertiary syphilis may not appear for 10 to 20 years after initial infection with syphilis. During this time, syphilis can damage organs, such as the brain, heart, blood vessels, liver, bones, and nerves, leading to serious complications.

Symptoms of tertiary syphilis include:

  • Delirium

  • Dementia

  • Gradual loss of vision

  • Loss of muscle coordination

  • Numbness

  • Paralysis

  • Psychosis

What causes syphilis?

Syphilis is a sexually transmitted disease caused by a bacterial infection of the bacterium Treponema pallidum. Syphilis can be passed from one person to another during sexual contact that involves vaginal, oral, or anal sex. Syphilis infection can also be passed from an infected mother to her baby during pregnancy.

Any person of any age who engages in sexual activity can contract and pass on a syphilis infection, including heterosexual, homosexual, and bisexual men and women.

What are the risk factors for syphilis?

A number of factors increase the risk of catching syphilis. Risk factors include:

  • Being a man who has sex with a man

  • Being born to a mother with syphilis

  • Having HIV/AIDS

  • Having multiple sexual partners (the more sexual partners a person has, the greater the risk of catching syphilis)

  • Having unprotected sex, including vaginal, oral, or anal sex, with a partner who has had one or more other sexual partners

  • Intravenous drug use

Reducing your risk of syphilis

It is important to understand that it is possible to transmit syphilis even when there are no symptoms. You can lower your risk of contracting and spreading syphilis and developing complications by :

  • Abstaining from sexual activity

  • Engaging in sexual activities only within a mutually monogamous relationship in which neither partner is infected with syphilis or has risk factors for the infection

  • Getting regular, routine medical care

  • Seeking medical care as soon as possible after possible exposure to syphilis or after high-risk sexual activity

  • Seeking prenatal care early and regularly during a pregnancy

  • Using a new latex condom for each sex act

How is syphilis treated?

Treatment of syphilis begins with seeking regular medical care throughout your life. Regular medical care allows your health care professional to best assess your risks of catching syphilis and promptly order further diagnostic testing as needed. These measures greatly increase the chances of diagnosing and treating syphilis in its earliest, most curable stage.

Prompt diagnosis and treatment can eliminate the risk of developing serious complications. If you have syphilis, you can help cure it and eliminate its transmission by consistently following your treatment plan. Treatment includes:

  • Abstaining from sexual activity until the infection is cured and your sexual partner(s) have been treated, even if they have no symptoms.

  • An intramuscular injection of the antibiotic penicillin. More doses of penicillin may be required for people who have had syphilis for more than a year.

What are the possible complications of syphilis?

Complications of untreated syphilis can be serious and life threatening. You can minimize the risk of serious complications for yourself, your unborn child, and your sexual partner(s) by following the treatment plan you and your health care professional design specifically for you. Complications of syphilis include:

  • An increased risk for contracting HIV, which causes AIDS

  • Aortic aneurysm

  • Birth defects

  • Blindness

  • Dementia

  • Paralysis

  • Stillbirth

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 9
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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