Syphilis is a bacterial infection that is most often spread through sexual contact.
Syphilis is a sexually transmitted, infectious disease caused by the spirochete bacterium Treponema pallidum. This bacterium causes infection when it gets into broken skin or mucus membranes, usually of the genitals. Syphilis is most often transmitted through sexual contact, although it also can be transmitted in other ways.
Syphilis occurs worldwide, most commonly in urban areas. The number of cases is rising fastest in men who have sex with men. Young adults ages 15 to 25 are the highest-risk population. People have no natural resistance to syphilis.
Because people may be unaware that they are infected with syphilis, many states require tests for syphilis before marriage. All pregnant women who receive prenatal care should be screened for syphilis to prevent the infection from passing to their newborn (congenital syphilis).
Syphilis has three stages:
- Primary syphilis
- Secondary syphilis
- Tertiary syphilis (the late phase of the illness)
Secondary syphilis, tertiary syphilis, and congenital syphilis are not seen as often in the United States as they were in the past because of the availability of:
- Free, government-sponsored sexually transmitted infection (STI) clinics
- Screening tests for syphilis
- Public education about STIs
- Prenatal screening
Symptoms of primary syphilis are:
- Small, painless open sore or ulcer (called a chancre) on the genitals, mouth, skin, or rectum that heals by itself in 3 to 6 weeks
- Enlarged lymph nodes in the area of the sore
The bacteria continue to grow in the body, but there are few symptoms until the second stage.
Secondary syphilis symptoms may include:
- Skin rash, usually on the palms of the hands and soles of the feet
- Sores called mucous patches in or around the mouth, vagina, or penis
- Moist, warty patches (called condylomata lata) in the genitals or skin folds
- General ill feeling
- Loss of appetite
- Muscle aches
- Joint pain
- Swollen lymph nodes
- Vision changes
- Hair loss
Symptoms of tertiary syphilis depend on which organs have been affected. They vary widely and can be difficult to diagnose. Symptoms include:
- Damage to the heart, causing aneurysms or valve disease
- Central nervous system disorders (neurosyphilis)
- Tumors of skin, bones, or liver
Exams and Tests
The doctor or nurse will examine you. Tests that may be done include:
- Examination of fluid from sore
- Echocardiogram, aortic angiogram, and cardiac catheterization to look at the major blood vessels and the heart
- Spinal tap and examination of spinal fluid
- Blood tests to screen for syphillis bacteria (RPR, VDRL, or TRUST)
If the RPR, VDRL, or TRUST tests are positive, one of the following tests will be needed to confirm the diagnosis:
- FTA-ABS (fluorescent treponemal antibody test)
Syphilis can be treated with antibiotics, such as:
- Penicillin G benzathine
- Tetracycline (for patients who are allergic to penicillin)
Length of treatment depends on how severe the syphilis is, and factors such as the patient's overall health.
To treat syphilis during pregnancy, penicillin is the drug of choice. Tetracycline cannot be used for treatment because it is dangerous to the unborn baby. Erythromycin may not prevent congenital syphilis in the baby. People who are allergic to penicillin should ideally be desensitized to it, and then treated with penicillin.
Several hours after getting treatment for the early stages of syphilis, people may experience the Jarisch-Herxheimer reaction. This process is caused by an immune reaction to the breakdown products of the infection.
Symptoms and signs of this reaction include:
- General ill feeling (malaise)
- Joint aches
- Muscle aches
These symptoms usually disappear within 24 hours.
Follow-up blood tests must be done at 3, 6, 12, and 24 months to ensure that the infection is gone. Avoid sexual contact when the chancre is present. Use condoms until two follow-up tests have shown that the infection has been cured, to reduce the chance of transmitting the infection.
All sexual partners of the person with syphilis should also be treated. Syphilis is extremely contagious in the primary and secondary stages.
Syphilis can be cured if it is diagnosed early and completely treated.
Secondary syphilis can be cured if it is diagnosed early and treated effectively. Although it usually goes away within weeks, in some cases it may last for up to 1 year. Without treatment, up to one-third of patients will have late complications of syphilis.
Late syphilis may be permanently disabling, and it may lead to death.
- Cardiovascular complications (aortitis and aneurysms)
- Destructive sores of skin and bones (gummas)
- Syphilitic myelopathy - a complication that involves muscle weakness and abnormal sensations
- Syphilitic meningitis
In addition, untreated secondary syphilis during pregnancy may spread the disease to the developing baby. This is called congenital syphilis.
When to Contact a Medical Professional
Call for an appointment with your health care provider if you have symptoms of syphilis.
Contact your doctor or nurse, or get screened in an STI clinic if you have:
- Had intimate contact with a person who has syphilis or any other STI
- Engaged in any high-risk sexual practices, including having multiple or unknown partners or using intravenous drugs
If you are sexually active, practice safe sex and always use a condom.
All pregnant women should be screened for syphilis.
Primary syphilis; Secondary syphilis; Late syphilis; Tertiary syphilis
Hook EW III. Syphilis. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 327.
Screening for syphilis infection in pregnancy: U.S. Preventive Services Task Force reaffirmation recommendation statement. Ann Intern Med. 2009;150:705-9. PMID: 19451577 www.ncbi.nlm.nih.gov/pubmed/19451577.
Tramont EC. Traponema pallidum (syphilis). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009:chap 238.
Workowski KA, Berman S. Centers for Disease Control and Prevention (CDC). Sexually transmitted diseases treatment guidelines, 2010. MMWR. 2010;59:1-110. PMID: 21160459 www.ncbi.nlm.nih.gov/pubmed/21160459.
Update Date 8/31/2014
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.