Skip to content


Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum.


a couple being consulted by the doctor

Syphilis is a sexually transmitted, bacterial infection that initially causes genital ulcers (sores). The bacterium that is causing syphilis is called Treponema pallidum. This bacterium is thin and of spiral shape, it has multiple hairlike protruding appendages that help it to move and spread in the body. Syphilis occurs exclusively in humans and is not found in animals.

If left untreated, the disease will progress to more severe infection and may lead to serious complications, including blindness and nerve damage. The disease goes through several different phases including primary, secondary, tertiary, and latent syphilis. It should be noted that syphilis is associated with HIV infection and HIV-infected individuals are more likely to develop severe syphilis and vice versa, those having syphilis are at risk of acquiring HIV.


The most common way to get syphilis is by having sexual contact with an infected person. An infected person can pass the bacteria from infected skin or mucous membranes (linings), usually the genital area, lips, mouth, or anus, to the mucous membranes or skin of the sexual partner. Syphilis can be passed from mother to infant during pregnancy, causing a disease called congenital syphilis. Blood transfusions and organ transplantation are also possible routes of disease transmission. The spread of syphilis through contact with toilet seats, doorknobs, swimming pools, hot tubs, bathtubs, shared clothing, or eating utensils is extremely unlikely.

Primary syphilis

The initial symptom of syphilis is a single, raised sore called a chancre. It usually appears on the genitals, mouth, or rectum an average of three weeks after exposure. When the chancre is on the penis or near the vagina, lymph nodes in the groin may also become swollen. Because the sore is painless, many people may ignore it unless it becomes infected. The sore can last for several weeks and go away by itself in 6 weeks. Without treatment, however, the person still has an infection in the body and can develop secondary syphilis.

Secondary syphilis

This stage usually starts with a reddish-brown, spotted rash on one or more areas of the body, but most often on the palms of the hands or soles of the feet. The rash usually does not itch and can appear as the chancre is healing or several weeks after the chancre has gone away. The rash may come and go for up to two years. Other common symptoms may include swollen lymph nodes, fever, fatigue, patchy hair loss, weight loss, and headache. These symptoms usually last from two to six weeks and will clear up with or without treatment.

Latent syphilis

The latent stage of the disease begins when symptoms of secondary syphilis subside. During this stage, syphilis becomes latent, which means it shows no signs or symptoms. The infection can be detected only via blood testing. A relapse of secondary syphilis can occur during the first two years of latency. If not treated, latent syphilis continues for life and may progress to the final tertiary stage.

Tertiary (late) syphilis

About one-third of people without treatment suffer serious damage to the nervous system, heart, brain, or other organs. Tertiary syphilis can cause paralysis, mental problems, blindness, deafness, heart failure, and even death. Individuals who are also infected with HIV can progress more rapidly to this late stage. Though treatment at this phase will cure the disease and stop future damage, it cannot repair or reverse the damage that occurred before treatment.


Microscopic examination of the tissues obtained from the skin lesions can help to detect bacteria. Additionally, a polymerase chain reaction test is performed to confirm the diagnosis. Antibodies to treponema can be found in the serum and are suggestive of either active disease or infection in the past. As the disease can affect the cardiovascular system angiography and chest CT are recommended to visualize the aorta and see if there are any abnormalities.  


At early stages, syphilis is treated with antibiotics. For primary and secondary infection single injection of penicillin in the muscle is sufficient. If a person is allergic to penicillin, other antibiotics may be prescribed. In case of late or latent disease, a 3-week long penicillin course when a dose of the drug is given weekly is recommended.  Syphilis with nervous system involvement requires more intensive treatment.

Persons who receive syphilis treatment must abstain from sexual contact with new partners until the syphilis sores are completely healed. Ill people must notify their sex partners so that they also can be tested and receive treatment if necessary.


In order to avoid transmission of sexually transmitted diseases, including syphilis, it is recommended to abstain from sexual contact or to maintain a long-term monogamous relationship with a partner who has been tested and is known to be free from any infections. Condoms can prevent transmission, but this method does not provide complete protection from sores and lesions.

NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.

DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

MediGoo - Health Medical Tests and Free Health Medical Information