Syphilis is a bacterial infection that is most often spread through sexual contact.
Primary syphilis; Secondary syphilis; Late syphilis; Tertiary syphilis
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:
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:
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.
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.
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.
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.