Syphilis is an infectious disease caused by Treponema pallidum bacteria. The bacteria are most commonly transmitted by direct contact with a syphilis sore, which typically occurs during vaginal, anal or oral sex. Untreated syphilis infections progress sequentially through primary, secondary, latent and late stages. The U.S. Centers for Disease Control and Prevention (CDC) issued "Sexually Transmitted Diseases Treatment Guidelines" in 2006. These guidelines include CDC's recommendations for the treatment of all stages of syphilis.
Benzathine Penicillin G for Adults
CDC's recommendation for the treatment of primary syphilis in nonpregnant adults is 2.4 million units of benzathine penicillin G administered intramuscularly in a single dose.
Benzathine Penicillin G for Children
For children with acquired primary syphilis--as opposed to congenital syphilis contracted from an infected mother--CDC recommends benzathine penicillin G at a dose of 50,000 units per kilogram of body weight up to the adult dose of 2.4 million units. The antibiotic is given by intramuscular injection in a single dose.
Oral Doxycycline or Tetracycline
Among nonpregnant adults and children with primary syphilis and penicillin allergy, CDC recommends treatment with two weeks of oral doxycycline or tetracycline. A 10-day course of ceftriaxone is also mentioned as a possible alternative to penicillin, although it is noted that some people with penicillin allergy also react to ceftriaxone.
Single dose, oral azithromycin has been used successfully in nonpregnant adults. However, the CDC warns that treatment failures and azithromycin resistance have been reported. CDC cautions that if compliance with a full course of antibiotic therapy and follow-up visits is uncertain, patients should undergo penicillin desensitization--a series of treatments to alleviate penicillin allergy--and then receive the recommended dose of benzathine penicillin G.
Pregnant Women without Penicillin Allergy
CDC's 2006 STD Treatment Guidelines state, "Penicillin is effective for preventing maternal transmission to the fetus and for treating fetal infection." CDC recommends pregnant women with primary syphilis should receive the same antibiotic regimen as nonpregnant adults with primary syphilis.
Pregnant Women with Penicillin Allergy
CDC recommends pregnant women with primary syphilis and penicillin allergy should undergo penicillin desensitization followed by the standard recommended treatment with benzathine penicillin G.
People with HIV
CDC recommends the treatment for people with primary syphilis and HIV should be the same as for those without HIV. However, some infectious disease specialists give three doses of 2.4 million units of benzathine penicillin G (once weekly for 3 consecutive weeks) rather than the recommended single dose of penicillin because of concerns over early invasion of the central nervous system. Regardless of which treatment regimen in chosen, careful follow-up after antibiotic therapy is necessary to monitor for possible treatment failure.
References
- "Principles and Practice of Infectious Diseases, Sixth Edition"; Gerald L. Mandell, M.D., John E. Bennett, M.D., Raphael Dolin, M.D., Editors; 2004
- Centers for Disease Control and Prevention: Syphilis fact sheet
- "Clinical Dermatology: A Color Guide to Diagnosis and Therapy"; Thomas P. Habif, M.D.; 1996
- Centers for Disease Control and Prevention: Primary and secondary syphilis treatment
- Centers for Disease Control and Prevention: Primary and secondary syphilis treatment, penicillin allergy
