Erythrasma is caused by ?
**Core Concept**
Erythrasma is a superficial fungal infection that affects the skin folds, particularly in intertriginous areas. It is caused by a specific type of bacteria that thrives in warm, moist environments. The pathogenesis involves the breakdown of keratin and the production of characteristic brown pigmentation.
**Why the Correct Answer is Right**
The correct answer is Corynebacterium minutissimum, a gram-positive bacterium that is specifically adapted to grow in the warm, moist environment of skin folds. This bacterium produces porphyrins, which are responsible for the characteristic brown pigmentation seen in erythrasma. The infection is more common in individuals with diabetes, obesity, and hyperhidrosis, where the skin folds are more prone to moisture accumulation.
**Why Each Wrong Option is Incorrect**
**Option A:** Staphylococcus aureus is a common cause of skin infections, but it is not associated with the characteristic brown pigmentation of erythrasma.
**Option B:** Candida albicans is a common cause of fungal infections, but it is not the primary cause of erythrasma.
**Option C:** Trichophyton rubrum is a common cause of dermatophyte infections, but it is not associated with the superficial bacterial infection of erythrasma.
**Clinical Pearl / High-Yield Fact**
Erythrasma is often misdiagnosed as a fungal infection, but it can be distinguished by its characteristic brown pigmentation and lack of scaling or pruritus.
**Correct Answer:** C. Corynebacterium minutissimum