A 34-year-old farmer from rural Assam presents with five days of high fever, severe myalgia, headache, and generalized lymphadenopathy. Examination reveals an ulcerated black scab with surrounding erythema on his left calf. Which drug is the treatment of choice?
- A Doxycycline ✓
- B Ceftriaxone
- C Chloroquine
- D Amoxicillin-clavulanate
Correct answer: A. Doxycycline
Explanation
An eschar with fever, myalgia, and lymphadenopathy in a rural Indian setting is classic for scrub typhus caused by Orientia tsutsugamushi, an obligate intracellular rickettsial organism. Rickettsiae live inside host cells, so beta-lactams that cannot penetrate cells are ineffective. Doxycycline is the drug of choice because tetracyclines concentrate intracellularly and inhibit the organism's protein synthesis. Azithromycin is an alternative in pregnancy or doxycycline intolerance, but doxycycline remains first line in endemic regions.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.