Syphilis: Management

Key points

• First-line: IM benzathine penicillin. Early syphilis (primary, secondary, early latent under 2 years): a single dose of benzathine penicillin 2.4 MU IM. Late latent, cardiovascular or gummatous syphilis: benzathine penicillin 2.4 MU IM once weekly for 3 weeks.
• Neurosyphilis: procaine penicillin IM (with oral probenecid) or IV benzylpenicillin for 14 days. Penicillin allergy: doxycycline 100 mg twice daily for 14 days (early) or 28 days (late/neurosyphilis).
• The Jarisch-Herxheimer reaction (fever, rash, tachycardia, myalgia within hours of the first dose) is common in early syphilis and self-limiting — manage with antipyretics (steroids for cardiovascular/neurological disease). Follow up with serial non-treponemal titres (RPR/VDRL) to confirm response.