From the Guidelines
For a patient with a reactive syphilis antibody screening test, the next step is to perform a confirmatory test, typically a treponemal-specific test such as the TP-PA (Treponema pallidum particle agglutination) or FTA-ABS (fluorescent treponemal antibody absorption), as recommended by the most recent guidelines 1. This approach is crucial because the use of only one type of test is insufficient for diagnosis, as false-positive nontreponemal test results can occur secondary to various medical conditions 1. Additionally, ordering an RPR (rapid plasma reagin) or VDRL (Venereal Disease Research Laboratory) test with titer is essential to assess disease activity and establish a baseline for monitoring treatment response 1. While awaiting results, obtaining a thorough sexual history and performing a complete physical examination looking for signs of primary, secondary, or tertiary syphilis is necessary. If confirmatory testing is positive, treatment depends on the stage of infection. For primary, secondary, or early latent syphilis (less than one year duration), administering benzathine penicillin G 2.4 million units IM as a single dose is recommended 1. For late latent syphilis (more than one year duration) or syphilis of unknown duration, giving benzathine penicillin G 2.4 million units IM weekly for three weeks is advised 1. For neurosyphilis, the regimen is aqueous crystalline penicillin G 3-4 million units IV every 4 hours for 10-14 days 1. For penicillin-allergic patients, doxycycline 100 mg orally twice daily for 14 days (primary, secondary, early latent) or 28 days (late latent) can be used 1. Follow-up serologic testing should be performed at 6,12, and 24 months after treatment to ensure adequate response, and partner notification and testing are essential components of management 1. Key considerations include the potential for treatment failures and the importance of monitoring for signs of disease recurrence or progression, particularly in patients with HIV co-infection or other immunocompromised states 1.
Some key points to consider in the management of syphilis include:
- The importance of using both nontreponemal and treponemal tests for diagnosis
- The need for careful staging of the disease to guide treatment decisions
- The potential for treatment failures and the importance of monitoring for signs of disease recurrence or progression
- The importance of partner notification and testing in preventing further transmission of the disease
- The need for careful consideration of the patient's immunological status, particularly in patients with HIV co-infection or other immunocompromised states.
In terms of specific treatment recommendations, the most recent guidelines suggest the following:
- Benzathine penicillin G 2.4 million units IM as a single dose for primary, secondary, or early latent syphilis
- Benzathine penicillin G 2.4 million units IM weekly for three weeks for late latent syphilis or syphilis of unknown duration
- Aqueous crystalline penicillin G 3-4 million units IV every 4 hours for 10-14 days for neurosyphilis
- Doxycycline 100 mg orally twice daily for 14 days (primary, secondary, early latent) or 28 days (late latent) for penicillin-allergic patients.
Overall, the management of syphilis requires careful consideration of the patient's clinical presentation, immunological status, and treatment history, as well as careful adherence to recommended treatment guidelines and follow-up protocols.
From the FDA Drug Label
Patients being treated for gonococcal infection should have a serologic test for syphilis before receiving penicillin. All cases of penicillin treated syphilis should receive adequate follow-up including clinical and serological examinations. Appropriate antimicrobial therapy and follow-up tests for these diseases should be initiated if infection is confirmed The next step for a patient with a reactive syphilis AB screening test is to:
- Confirm the diagnosis with a treponemal test (not mentioned in the label, but a standard medical practice)
- Initiate antimicrobial therapy as indicated by the test results
- Provide adequate follow-up, including clinical and serological examinations, as recommended by the CDC 2
- Consider penicillin G as a treatment option for syphilis, but only under the guidance of a physician and with careful monitoring for potential adverse effects 2.
- Azithromycin should not be relied upon to treat syphilis 3.
From the Research
Next Steps for Reactive Syphilis Ab Screening Test
- Confirm the diagnosis with a treponemal test, such as the Fluorescent Treponemal Antibody-Absorption test (FTA-ABS) or the Microhemagglutination Assay for Antibodies to T. pallidum (MHA-TP) 4
- Evaluate the patient's medical history, including any previous treatments for syphilis and any potential allergies to penicillin
- Consider the stage of syphilis, as treatment may vary depending on the stage of the disease
Treatment Options
- Benzathine penicillin G is the recommended treatment for early syphilis in non-penicillin-allergic patients 5, 6, 7
- Azithromycin may be considered as an alternative treatment, but its effectiveness is still being studied and it may not be suitable for all patients due to resistance concerns 5, 6, 7
- Doxycycline may be used as a second-line treatment, but its success rate may be lower than penicillin, especially in late and undetermined syphilis infections 8