A 35-year-old woman from Mumbai presents with a maculopapular rash involving the trunk and extremities (including palms and soles) for 2 weeks. She also reports fever, generalized lymphadenopathy, and a history of a painless genital ulcer that healed spontaneously 8 weeks ago. RPR titre is 1:64 (positive). FTA-ABS is positive. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis: Secondary Syphilis The patient has classic features of **secondary syphilis**: - **Maculopapular rash** involving trunk, extremities, **palms, and soles** (highly characteristic) - **Systemic symptoms:** fever, generalized lymphadenopathy - **History of primary chancre** (painless genital ulcer) that healed spontaneously ~8 weeks prior - **Serological confirmation:** RPR positive (1:64), FTA-ABS positive (confirms treponemal infection) ### Staging and Treatment Regimens (CDC STI Guidelines 2021) | Stage | Duration | Penicillin Regimen | |---|---|---| | **Primary / Secondary / Early Latent** | < 1 year | Benzathine PCN G **2.4 MU IM × 1 dose** | | **Late Latent / Tertiary (non-neuro)** | > 1 year or unknown | Benzathine PCN G 2.4 MU IM weekly × 3 weeks | | **Neurosyphilis** | Any | Aqueous PCN G IV 18–24 MU/day × 10–14 days | **Key Point:** Per **CDC 2021 STI Treatment Guidelines** and **Harrison's Principles of Internal Medicine (21e, Ch. 207)**, both primary AND secondary syphilis are treated with a **single dose** of benzathine penicillin G 2.4 million units IM. The 3-week regimen is reserved for late latent syphilis (>1 year duration) or syphilis of unknown duration — NOT for secondary syphilis. This is a critical distinction frequently tested in NEET PG. ### Why Option D is Correct This patient has **secondary syphilis of < 1 year duration** (primary chancre appeared ~8 weeks ago). The correct treatment is: - **Benzathine penicillin G 2.4 million units IM — single dose** - Followed by observation for **Jarisch-Herxheimer reaction (JHR)** ### Jarisch-Herxheimer Reaction (JHR) **Mnemonic:** **JHR = FEVER, RIGORS, RASH FLARE in first 24 hours** - **Incidence:** 50–90% in secondary syphilis (highest risk of any stage) - **Timing:** 1–6 hours after first penicillin injection - **Symptoms:** Fever, chills, myalgia, headache, tachycardia, worsening of existing rash - **Management:** Supportive care — NSAIDs, antipyretics; resolves in 12–24 hours - **Significance:** NOT a contraindication to penicillin; does NOT require stopping therapy **Clinical Pearl:** Patients with secondary syphilis should be **counselled about JHR before treatment** and observed after the injection. This is why option D correctly pairs the single-dose regimen with JHR monitoring. ### Why the Other Options Are Incorrect - **Option A (LP before treatment):** Lumbar puncture is indicated only if neurological, ocular, or otic symptoms are present, or in HIV co-infection with CD4 < 100. This patient has no such features; LP is not the immediate next step. - **Option B (3 weekly injections):** This regimen is for **late latent syphilis or syphilis of unknown duration**, NOT secondary syphilis. Applying it here is an over-treatment error. - **Option C (Chest X-ray + HIV serology before treatment):** While HIV co-testing is recommended concurrently, it should not **delay** treatment. Chest X-ray is not routinely indicated in secondary syphilis without pulmonary symptoms. **High-Yield:** The **rash on palms and soles** = secondary syphilis = **single dose** benzathine penicillin G 2.4 MU IM. The 3-dose regimen is a common distractor. [cite: CDC STI Treatment Guidelines 2021; Harrison's Principles of Internal Medicine 21e, Ch. 207; WHO Guidelines for the Treatment of Treponema pallidum (Syphilis) 2016]