A 32-year-old farmer from Tamil Nadu presents with a 5-day history of fever, headache, myalgia, and a characteristic eschar on his left thigh. Serological tests for scrub typhus (IgM ELISA) are positive. He is haemodynamically stable with normal renal function. What is the most appropriate immediate management?

Explanation

## Management of Scrub Typhus — Confirmed Case ### Clinical Context This patient has: - Classic eschar (pathognomonic for scrub typhus) - Positive IgM serology (diagnostic in endemic region) - Haemodynamic stability and normal renal function - Early-stage disease (day 5) ### Rationale for Doxycycline **Key Point:** Doxycycline is the first-line antibiotic for scrub typhus in non-pregnant, non-paediatric patients, regardless of disease severity. **High-Yield:** Early initiation of doxycycline (within 5–7 days of symptom onset) prevents progression to severe complications (ARDS, myocarditis, renal failure, DIC) and dramatically reduces mortality from ~1–5% to <1%. **Clinical Pearl:** The eschar is a hallmark sign of *Orientia tsutsugamushi* infection and confirms the diagnosis; serology + eschar = treat immediately without awaiting culture. ### Dosing & Duration - **Doxycycline:** 100 mg orally twice daily for 7–10 days - **Alternative (if doxycycline contraindicated):** Chloramphenicol 500 mg QID or azithromycin 500 mg daily - **Severe/complicated cases:** May require IV doxycycline or chloramphenicol ### Why Delay is Harmful Deferring antibiotics in confirmed scrub typhus increases risk of: - Multi-organ involvement - Disseminated intravascular coagulation (DIC) - Acute respiratory distress syndrome (ARDS) - Mortality [cite:Harrison 21e Ch 175]