Treatment for Active Syphilis Infection
This patient has confirmed active syphilis requiring immediate treatment with benzathine penicillin G 2.4 million units IM as a single dose, as the reactive RPR (1:1) combined with positive TPHA and EIA confirms current infection. 1
Understanding the Serologic Pattern
The combination of reactive RPR with positive treponemal tests (TPHA and EIA) definitively confirms syphilis infection, as both nontreponemal and treponemal tests must be positive for diagnosis. 1, 2
The RPR titer of 1:1 represents the lowest dilution tested and indicates active infection requiring treatment, though the low titer suggests either very early infection, late latent disease, or previously treated infection with residual activity. 1
The previous negative EIA results followed by detected EIA indicate seroconversion, strongly suggesting recent infection acquisition. 1
Determining Disease Stage and Treatment Regimen
Clinical evaluation is essential to determine the appropriate treatment duration:
Evaluate for primary syphilis signs: Look for chancre or ulcer at potential infection sites (genital, oral, anal). If present, treat with benzathine penicillin G 2.4 million units IM as a single dose. 1, 3
Evaluate for secondary syphilis manifestations: Examine for rash (particularly palms/soles), mucocutaneous lesions, or lymphadenopathy. If present, treat with benzathine penicillin G 2.4 million units IM as a single dose. 1, 3
Screen for neurosyphilis/tertiary disease: Assess for neurologic symptoms (headache, vision changes, hearing loss, confusion), ocular symptoms, or cardiovascular manifestations. If any are present, perform lumbar puncture for CSF examination before treatment. 1, 2
If asymptomatic (latent syphilis): The staging depends on timing of infection acquisition:
Critical Pre-Treatment Evaluations
HIV testing is mandatory for all patients with syphilis, as HIV coinfection affects monitoring frequency (every 3 months instead of 6 months) and increases neurosyphilis risk. 1, 3
Pregnancy testing is essential in women of childbearing age, as treatment must occur >4 weeks before delivery for optimal outcomes, and penicillin-allergic pregnant women require desensitization. 3
Sexual partner notification: Identify and presumptively treat all sexual contacts from the past 90 days (for primary syphilis), 6 months (for secondary syphilis), or 12 months (for early latent syphilis), even if seronegative. 3
Follow-Up Monitoring Schedule
For primary/secondary/early latent syphilis: Clinical and serologic evaluation (quantitative RPR) at 6 and 12 months after treatment. 1, 3
For late latent or unknown duration: Clinical and serologic evaluation at 6,12,18, and 24 months after treatment. 1, 3
Treatment success criteria: A fourfold decline in RPR titer (e.g., from 1:4 to 1:1, or from 1:1 to nonreactive) within 6-12 months for early syphilis or 12-24 months for late latent syphilis. 1, 3
HIV-infected patients require more intensive monitoring at 3,6,9,12, and 24 months due to higher treatment failure risk and atypical serologic responses. 1, 3
Important Warnings and Pitfalls
Jarisch-Herxheimer reaction: Warn the patient about potential acute febrile reaction with headache and myalgia within 24 hours of treatment, which does not indicate treatment failure. 3
Sequential testing must use the same method (RPR vs VDRL) and preferably the same laboratory, as titers are not directly comparable between methods. 1, 2
Treponemal tests (TPHA, EIA) remain positive for life in 75-85% of patients regardless of treatment success and should never be used to monitor treatment response—only RPR titers should be followed. 1, 2
Penicillin allergy management: For non-pregnant patients with early syphilis, doxycycline 100 mg orally twice daily for 14 days is an alternative. For late latent syphilis or pregnancy, penicillin desensitization is mandatory. 1, 3
Do not delay treatment while awaiting additional test results if clinical suspicion is high and the patient is at risk for loss to follow-up. 3