Overview, Causes, & Risk Factors

Syphilis is a sexually transmitted disease, or STD, caused by the Treponema pallidum bacteria. Less often, syphilis is transmitted from a pregnant woman to her baby. This form of syphilis is known as congenital syphilis.

What is going on in the body?

A person can develop syphilis 10 to 90 days after contact with the Treponema pallidum bacteria. Most people develop symptoms about 3 weeks after contact. This initial infection is known as primary syphilis.

If the Treponema pallidum bacteria are not effectively killed at this time, the person may develop secondary syphilis. This stage of the infection may show up right after the initial infection clears, or it may be delayed for several weeks.

If the syphilis is not treated effectively, the bacteria remains in the body. This period is known as latent syphilis. The Treponema pallidum bacteria travels to many vital organs. It may infect the brain, heart, eyes, nerves, and bones. Many years later, the person may develop tertiary syphilis.

What are the causes and risks of the infection?

Treponema pallidum is the cause of syphilis. The organism is spread from one person to another through direct contact with a syphilis sore. These sores are usually seen on the genitals or anus. However, they can also be found on the lips and inside the mouth. Therefore, syphilis can be spread by vaginal, anal, or oral sex. It can also be passed from a pregnant woman to her fetus.

Symptoms & Signs

What are the signs and symptoms of the infection?

Primary syphilis can cause one or more painless ulcers, or sores, at the point where the bacteria entered the body. These sores are usually on the genitals. They may also be found around the anus, in the rectum or vagina, on the lips, and in the mouth.

Secondary syphilis involves a generalized rash that usually appears on the palms and soles. The usual rash appears as red spots that can be flat or raised. However, many different skin rashes can occur. Following are other symptoms of secondary syphilis:

Sometimes people can develop meningitis, which is an inflammation of the membrane lining the brain and spinal cord. Secondary syphilis may cause may cause eye, kidney, or liver problems.

Tertiary syphilis can involve any organ of the body. When the brain is involved, it is called neurosyphilis. Some of the problems neurosyphilis can cause are as follows:

People with congenital syphilis can have no symptoms or very severe symptoms. It can even cause death. As with syphilis that is acquired sexually, congenital syphilis can affect any organ in the body.

The usual symptoms of congenital syphilis include the following:

If left untreated, the late signs of congenital syphilis include subtle bone malformations, malformed teeth, and eye and brain problems.

Diagnosis & Tests

How is the infection diagnosed?

Diagnosis of syphilis begins with a medical history and physical exam. The healthcare provider may order an antibody titer blood test. The provider can also look for the organism in a sample of genital secretions under a microscope.

Prevention & Expectations

What can be done to prevent the infection?

Safer sex practices can reduce the spread of syphilis. A barrier method, such as a condom, can help reduce a person's risk. Some male condoms are made with the spermicide nonoxynol-9, which helps kill some organisms that cause STDs. Female condoms provide some protection against infection. Anyone diagnosed with syphilis should encourage his or her recent sexual partners to be screened and treated. People infected with the AIDS virus, as well as certain other STDs, should be tested for syphilis. Pregnant women should be screened for syphilis and treated if positive.

What are the long-term effects of the infection?

If left untreated, syphilis is very serious. It can result in neurosyphilis, cardiovascular syphilis, and tumors of the skin, bones, and other organs.

What are the risks to others?

Syphilis is an STD that can be spread from person to person. It can also be passed from a pregnant woman to her baby.

Treatment & Monitoring

What are the treatments for the infection?

A single dose of penicillin can cure syphilis, if the individual has had it for less than a year. A person who has had syphilis for longer than a year will need larger doses of penicillin. Other antibiotics may be used for people who are allergic to penicillin.

What are the side effects of the treatments?

Penicillin and other antibiotics may cause rash and allergic reactions. They may also cause diarrhea, stomach upset, and nausea.

What happens after treatment for the infection?

If syphilis is treated effectively and on time, the person will have no further problems.

How is the infection monitored?

Any new or worsening symptoms should be reported to the healthcare provider.