Syphilis is a bacterial infection spread by sexual contact. If left untreated, it can cause brain, nerve, and tissue damage, or even death.


Syphilis is caused by the bacterium, Treponema pallidum . The bacterium is passed from person-to-person through direct contact with a syphilis lesion. Syphilis is spread by:

  • Vaginal, anal, or oral sexual contact with an infected person
  • A pregnant woman who passes the infection to her unborn baby (called congenital syphilis)
  • Blood exposure, such as through illegal drug use, or rarely, blood transfusions

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Risk factors include:

  • Age: 15 to 34
  • Having sex with a person infected with syphilis
  • Having multiple sex partners
  • Not using a latex condom during vaginal, anal, or oral sex (in a relationship that is not mutually faithful or where syphilis status is unknown)
  • Touching a syphilis lesion
  • Past or current sexually transmitted disease


There are four stages of syphilis in adults: primary stage, secondary stage, latency stage, and tertiary stage.

Primary (First) Stage

Single or multiple lesions (chancres) appear within 10 to 90 days of exposure, in the area where the infection was originally transmitted, such as the genitals, rectum, tongue, inside of the mouth, or lips. The lesion is initially raised or blister-like and painless, but gradually breaks down to form an induration or ulcer. The ulcer is painless at first. It usually has raised edges and is firm and round. Sometimes these lesions acquire a second bacterial infection and may then become painful. The ulcers usually last for 1 to 5 weeks and will heal on their own. During this time, you may notice enlarged lymph nodes in your groin. Without treatment, the infection may move to the secondary stage (even if the ulcers are no longer visible).

Lymph Nodes

Male Lymph nodes

© 2008 Nucleus Medical Art, Inc.

Secondary Stage

This stage develops from several weeks to months after infection. It starts with a pink or red-colored rash that usually doesn't itch but often occurs with a sore throat , swollen glands, headache, and other flu -like symptoms. It may appear on one or more areas of the skin. The rash usually lasts 2 to 6 weeks and may appear as the following:

  • Prickly heat
  • Small blotches or scales
  • Moist warts in the groin area
  • Slimy white patches in the mouth
  • Sunken dark circles the size of a nickel or dime
  • Rashes on the palms and soles
  • Fever
  • Fatigue
  • Achiness
  • Swollen lymph nodes throughout the body

Latency (Resting) Stage

This stage is characterized by a persistent infection without symptoms. This may last for many years and may or may not progress to the third stage. Blood tests for syphilis will be positive during this stage, which is how it is diagnosed. This stage is then further divided into the following:

  • Early latency—usually lasts for the first year after having primary or secondary syphilis. This is the period when most syphilis infections are spread to other people.
  • Late latency—people are usually not infectious during this stage. However, a pregnant woman can pass the syphilis infection to her developing fetus during this stage.

Tertiary (Third or Late) Stage

Develops many months, or even years after the initial infection. This stage has become very rare in developed or industrialized countries. In the tertiary stage, the bacterium begins to damage the brain, nerves, eyes, heart, blood vessels, liver, bones, and joints. Damage can be serious enough to cause death. Symptoms include the following:

  • Small bumps (called gummas) on the skin, bones, or internal organs
  • Heart and blood vessel problems
  • Blindness
  • Central nervous system damage, including weakness, numbness, trouble walking, difficulty with balance, memory problems, and loss of bladder control

Congenital Syphilis

This type of syphilis occurs when a pregnant women passes syphilis to her unborn child. The incidence of this problem in the United States and other developed countries is now relatively low since testing for syphilis is part of routine prenatal care.

In the early stages of congenital syphilis, infants may have symptoms similar to secondary syphilis in adults except that the rash may appear more like blisters. Late congenital syphilis occurs after age 2 and may be latent or may show nerve damage (such as deafness) or bone formation problems (often involving the teeth and nose).

Fetal Infection


© 2008 Nucleus Medical Art, Inc.


The doctor will ask about your symptoms and medical history, and perform a physical exam. The doctor will look for lesions or rashes on the body and genital area. Material from infectious lesions may be examined under a microscope, using a special test called darkfield microscopy. A blood test can detect antibodies to syphilis. If neurologic symptoms are present, a spinal tap (use of a needle to remove fluid from around the spinal cord) may be performed to check the fluid around the brain and spinal cord.


Penicillin kills the bacterium and prevents further damage. One dose will usually cure a person who has had syphilis for less than a year. If syphilis has been present for more than a year, more doses are needed. A baby born with syphilis needs daily penicillin treatment for at least 10 days. Penicillin will not repair any damage already done.

People who are allergic to penicillin can either be desensitized or can be given alternate antibiotics, such as doxycycline , ceftriaxone , tetracycline , or azithromycin .

Anyone infected with syphilis should avoid sexual relations until treatment is complete and the infection is cleared up. All sex partners should be notified so they can get treatment as well.


Syphilis lesions can be hidden in the vagina, rectum, or mouth. It may not be obvious that a sex partner has syphilis. The following practices can help prevent syphilis:

  • Abstaining from vaginal, anal, and oral sex
  • Having a mutually monogamous sexual relationship with an uninfected partner
  • Using a latex condom during vaginal, anal, and oral sex, especially if you have sexual contact with a partner whose syphilis status you are not certain of
  • Having regular checkups for sexually transmitted diseases


American Social Health Association

Centers for Disease Control and Prevention, National Prevention Information Network


Canadian Health Network

Sex Information and Education Council of Canada


Centers for Disease Control and Prevention website. Available at: .

Ferri. Ferri's Clinical Advisor: Instant Diagnosis and Treatment . 8th ed. Mosby, An Imprint of Elsevier; 2006.

Last reviewed January 2008 by David Horn, MD, FACP

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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