A woman presents with multiple, deep, painful, punched-out ulcers with undermined edges on the labia. Culture on chocolate agar shows small, Gram-negative coccobacilli. Which organism is responsible and what is the drug of choice as per current Indian guidelines?

• A Treponema pallidum — Benzathine penicillin
• B Klebsiella granulomatis — Doxycycline
• C Calymmatobacterium — Cotrimoxazole
• D Haemophilus ducreyi — Azithromycin 1g single dose ✓

Explanation

Chancroid (soft sore) is caused by Haemophilus ducreyi, a fastidious Gram-negative coccobacillus that requires X-factor (hemin) for growth. Clinically it presents as painful, soft, ragged-edged ulcers with tender unilateral bubo. Current WHO/NACO guidelines recommend azithromycin 1g orally single dose OR ceftriaxone 250mg IM single dose. Doxycycline is the DOC for donovanosis (K. granulomatis). Benzathine penicillin 2.4MU is for syphilis.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.