Syphilis

Diagnosis

Syphilis can sometimes be detected with an at-home test, but a positive result needs confirmation by a healthcare professional to start treatment.

Healthcare professionals diagnose syphilis by testing samples of:

• Blood. Tests detect antibodies that the immune system produces to fight the bacteria causing syphilis. These antibodies can remain in the body for years, showing a current or past infection.

• Fluid from a sore. Laboratory examination of the fluid under a microscope can confirm that syphilis caused the sore.

• Cerebrospinal fluid. If nervous system involvement is suspected, a sample of the fluid surrounding the brain and spinal cord may be tested through a lumbar puncture.

Partner notification and testing through local health departments help limit the spread of syphilis.

Treatment

Syphilis is highly treatable, especially in early stages.

• Medications. Penicillin is the preferred antibiotic at all stages. For those allergic to penicillin, alternative antibiotics or a penicillin desensitization procedure may be recommended.

• Dosage. Early-stage syphilis usually requires a single shot of penicillin. Syphilis lasting longer than a year may need additional doses. Pregnant individuals must receive penicillin to prevent congenital syphilis, with desensitization if allergic.

• Jarisch-Herxheimer reaction. Some may experience fever, chills, nausea, achy pain, and headache on the first day of treatment, which typically resolves within a day.

Treatment follow-up includes:

• Regular blood tests and exams to confirm the infection is cured.

• Avoiding sexual contact with new partners until treatment is complete and any sores have healed.

• Informing sexual partners so they can be tested and treated if necessary.

• HIV testing to check for co-infection.