What is the treatment for a syphilis rash?

Treatment for Syphilis Rash (Secondary Syphilis)

For a patient presenting with syphilis rash (secondary syphilis), administer benzathine penicillin G 2.4 million units intramuscularly as a single dose. 1, 2

First-Line Treatment

• Benzathine penicillin G 2.4 million units IM in a single dose is the definitive treatment for primary and secondary syphilis, including patients presenting with the characteristic rash. 1, 3
• This regimen has been used effectively for over 50 years to achieve clinical resolution, heal lesions, prevent sexual transmission, and prevent late sequelae. 3
• Parenteral penicillin G is the only therapy with documented efficacy across all stages of syphilis. 3

Alternative Regimens (Penicillin Allergy Only)

• Doxycycline 100 mg orally twice daily for 14 days is the alternative for non-pregnant patients with documented penicillin allergy. 1, 4
• The FDA-approved dosing for early syphilis in penicillin-allergic patients is doxycycline 100 mg by mouth twice daily for 2 weeks. 4
• Critical caveat: Pregnant women with syphilis at any stage who report penicillin allergy must be desensitized and treated with penicillin, as it is the only effective treatment during pregnancy. 3

Special Populations Requiring Modified Approach

HIV-Infected Patients

• Most HIV-infected patients respond appropriately to standard benzathine penicillin therapy. 3
• However, some experts recommend CSF examination before therapy to rule out neurosyphilis, as HIV-infected patients may have more apparent clinical lesions and accelerated disease progression. 3, 1
• All patients with syphilis should be tested for HIV. 1

Pregnant Women

• Treatment should be the penicillin regimen appropriate for the woman's stage of syphilis. 3
• Some experts recommend additional therapy (a second dose of benzathine penicillin 2.4 million units IM) 1 week after the initial dose, particularly for women in the third trimester or those with secondary syphilis during pregnancy. 3

Important Clinical Considerations

Jarisch-Herxheimer Reaction

• Patients should be warned about this acute febrile reaction accompanied by headache and myalgia that frequently occurs within the first 24 hours after treatment. 3
• This reaction occurs most often in patients with early syphilis (primary and secondary stages). 3
• Antipyretics may be used, though they have not been proven to prevent this reaction. 3
• In pregnant women, this reaction may induce early labor or fetal distress, but this concern should not prevent or delay therapy. 3

Administration Recommendations

• Adequate fluid intake is recommended with oral medications to reduce risk of esophageal irritation. 4
• If gastric irritation occurs with doxycycline, it may be given with food or milk without significantly affecting absorption. 4

Follow-Up Requirements

• Quantitative nontreponemal tests (VDRL or RPR) should be repeated at 3,6,12, and 24 months after treatment. 1
• A fourfold decline in titer is expected within 6 months for primary/secondary syphilis. 1
• Treatment failure is defined as failure of nontreponemal test titers to decline fourfold within 6 months after therapy. 1
• Sequential serologic tests should be performed using the same testing method by the same laboratory, as VDRL and RPR titers are not directly comparable. 3

Partner Management

• Sexual transmission occurs only when mucocutaneous lesions (like the rash of secondary syphilis) are present. 3
• Persons exposed within 90 days preceding diagnosis should be treated presumptively, even if seronegative. 3
• For secondary syphilis, the lookback period for partner notification is 6 months plus duration of symptoms. 3