Congenital Syphilis

Clinical assessment

Suspicion based on maternal syphilis history and/or infant signs/symptoms consistent with congenital syphilis.

Investigations

• Maternal Serology: Review mother's syphilis test results (RPR/VDRL and TPHA/TPPA) and treatment history.
• Infant Serology:
• - Non-treponemal test (RPR/VDRL) on infant serum (NOT cord blood). A titer fourfold higher than the mother's titer is suggestive of infection.
• - Treponemal test (TPHA/TPPA) on infant serum - difficult to interpret <18 months due to passive maternal antibodies.
• CSF Examination (Lumbar Puncture): Recommended for all infants with confirmed or highly probable congenital syphilis, or neurological signs. Assess for pleocytosis, elevated protein, and positive CSF-VDRL.
• Long Bone X-rays: Look for characteristic osteochondritis/periostitis.
• Complete Blood Count (CBC) with differential.
• Liver Function Tests (LFTs).
• Chest X-ray (if respiratory symptoms).
• Ophthalmologic exam.
• Auditory evaluation (Brainstem Auditory Evoked Response - BAER).

Diagnostic criteria

Confirmed congenital syphilis requires visualization of T. pallidum in body fluids/lesions (rarely done). Presumptive diagnosis based on combination of: Maternal syphilis status/treatment adequacy, Infant clinical findings, Infant non-treponemal titer compared to mother's, CSF findings, Long bone X-ray findings.

Non-pharmacological management

• Supportive care for complications (e.g., feeding difficulties, respiratory support).

Pharmacological treatment

• Treatment depends on diagnostic certainty and whether CSF evaluation was performed/normal.
• Scenario 1: Proven or Highly Probable Congenital Syphilis (Positive CSF VDRL, or Abnormal CSF cells/protein with positive infant serology, or Positive darkfield/PCR from infant):
• - Aqueous Crystalline Penicillin G 100,000-150,000 units/kg/day, administered as 50,000 units/kg/dose IV every 12 hours for first 7 days of life, then every 8 hours, for a total of 10 days.
• - OR Procaine Penicillin G 50,000 units/kg/dose IM once daily for 10 days.
• Scenario 2: Normal CSF evaluation AND Infant RPR/VDRL titer ≥ fourfold mother's titer OR Positive infant treponemal test with physical/radiographic evidence:
• - Treat as above with 10-day course of Aqueous Pen G or Procaine Pen G.
• Scenario 3: Normal CSF, Normal physical exam, Infant RPR/VDRL ≤ fourfold mother's titer, AND Mother inadequately treated (<4 weeks before delivery, non-penicillin regimen, unknown treatment, evidence of relapse/reinfection):
• - Treat as above with 10-day course of Aqueous Pen G or Procaine Pen G.
• - OR Benzathine Penicillin G 50,000 units/kg IM single dose (ONLY if CSF normal and close follow-up assured).
• Scenario 4: Normal CSF, Normal physical exam, Infant RPR/VDRL ≤ fourfold mother's titer, AND Mother adequately treated (>4 weeks before delivery with appropriate penicillin regimen, no signs of reinfection):
• - Benzathine Penicillin G 50,000 units/kg IM single dose.
• - Some guidelines suggest close follow-up without treatment is an option if follow-up is certain.
• Treat both parents appropriately for their stage of syphilis.

Monitoring

• Clinical monitoring for resolution of signs.
• Serological follow-up with RPR/VDRL titers at 3, 6, 12 months until non-reactive or low stable titer.
• Repeat CSF exam at 6 months if initially abnormal.
• Long-term ophthalmologic and audiologic follow-up.