A 35-year-old woman from Delhi presents with a 2-month history of fever, malaise, and a maculopapular rash on her trunk and palms. She reports a painless genital ulcer that healed spontaneously 8 weeks ago. Examination reveals generalized lymphadenopathy, hepatosplenomegaly, and condylomata lata in the perianal region. RPR is positive (1:64), FTA-ABS is positive, and CSF examination is normal. What is the most likely diagnosis?

Explanation

## Diagnosis: Secondary Syphilis ### Clinical Timeline and Staging | Stage | Timeline | Key Features | |-------|----------|---------------| | **Primary** | 3–90 days post-exposure | Painless chancre, regional lymphadenopathy | | **Secondary** | 4–10 weeks after chancre (2–8 weeks after primary heals) | Systemic symptoms, rash, mucous patches, condylomata lata | | **Early latent** | <1 year after primary | Asymptomatic, serology positive | | **Late latent** | >1 year | Asymptomatic, serology positive | | **Tertiary** | Years to decades | Neurosyphilis, cardiovascular, gummatous | **Key Point:** This patient is 8 weeks post-chancre with systemic manifestations → **secondary syphilis**. ### Hallmark Features of Secondary Syphilis 1. **Constitutional symptoms**: Fever, malaise, fatigue, headache 2. **Rash**: Maculopapular (trunk, extremities, **palms and soles** — pathognomonic) 3. **Mucous patches**: Painless, highly infectious erosions in mouth 4. **Condylomata lata**: Broad, flat, moist papules in intertriginous areas (perianal, inguinal) — highly infectious 5. **Lymphadenopathy**: Generalized, non-tender 6. **Hepatosplenomegaly**: Common 7. **Serology**: High RPR titre (1:64 indicates high spirochaetemia) **High-Yield:** Condylomata lata are pathognomonic for secondary syphilis and are teeming with organisms (highly contagious). ### Why NOT Early Neurosyphilis? **Clinical Pearl:** Although *T. pallidum* invades the CNS in ~25% of untreated syphilis, **symptomatic neurosyphilis** (meningitis, paresis, tabes) typically emerges in tertiary stage or late secondary. This patient has: - **Normal CSF** (rules out active meningitis) - **No neurological symptoms** (no cranial nerve palsies, no psychiatric changes, no ataxia) - **Systemic manifestations** consistent with secondary syphilis Asymptomatic CSF involvement (neurosyphilis serology positive but CSF normal) can occur in secondary syphilis but does NOT change the primary diagnosis or immediate management. ### Why NOT Tertiary Syphilis? Tertiary syphilis (gummatous, cardiovascular, neurosyphilis with paresis/tabes) develops **years to decades** after primary infection, not 8 weeks. Gummas are granulomatous lesions of skin, bone, viscera — not the acute rash and condylomata lata seen here. ### Why NOT Latent Syphilis? Latent syphilis is **asymptomatic** by definition. This patient has fever, rash, hepatosplenomegaly, and condylomata lata — all active symptoms. ### Management of Secondary Syphilis **Benzathine penicillin G 2.4 million units IM weekly × 3 doses** (total 7.2 million units over 3 weeks) [cite:Harrison 21e Ch 210]. - Higher total dose and longer duration than primary syphilis (due to higher spirochaetal burden) - Achieves treponemicidal levels throughout the extended treatment window ### Serological Response - RPR should decline 4-fold by 6 months, become negative by 12–24 months - FTA-ABS remains positive indefinitely