A 28-year-old obese man presents with reddish-brown, finely wrinkled macules in both axillae with minimal itching. Wood's lamp examination shows a coral-red fluorescence. Which organism is responsible?
- A Malassezia furfur
- B Corynebacterium minutissimum ✓
- C Candida albicans
- D Trichophyton rubrum
Correct answer: B. Corynebacterium minutissimum
Explanation
Erythrasma is a superficial bacterial infection of intertriginous areas caused by Corynebacterium minutissimum. The organism produces coproporphyrin III, which fluoresces coral-red under Wood's light, a finding that distinguishes it from tinea cruris and candidal intertrigo. Malassezia fluoresces pale yellow-green in pityriasis versicolor, and Trichophyton rubrum does not produce this fluorescence pattern.
Reference: Fitzpatrick's Dermatology, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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