Which organism causes tinea versicolor?

Which organism causes tinea versicolor?

• A. Malassezia Furfur
• B. Trichophyton Rubrum
• C. Candida Albicans
• D. Aspergillus Fumigatus

Answer: (A)

Tinea versicolor is caused by a lipophilic yeast that colonizes the outer skin layer, especially oily areas. Malassezia furfur thrives in the skin’s stratum corneum and metabolizes skin lipids into acids that disrupt melanocyte melanin production, leading to the characteristic pale or dark patches on the trunk and shoulders. This organism is the best answer because it is the classic etiologic agent of this condition, historically referred to as Pityrosporum species and specifically Malassezia furfur. In contrast, Trichophyton rubrum is a dermatophyte that causes tinea infections of keratinized tissues (like feet or nails), Candida albicans causes candidiasis, and Aspergillus fumigatus causes aspergillosis; none of these produce tinea versicolor. Diagnostic clues can include spaghetti-and-meatballs appearance on KOH prep and a copper-orange fluorescence under Wood’s lamp, reflecting Malassezia’s pigment-related byproducts.

Tinea versicolor is caused by a lipophilic yeast that colonizes the outer skin layer, especially oily areas. Malassezia furfur thrives in the skin’s stratum corneum and metabolizes skin lipids into acids that disrupt melanocyte melanin production, leading to the characteristic pale or dark patches on the trunk and shoulders. This organism is the best answer because it is the classic etiologic agent of this condition, historically referred to as Pityrosporum species and specifically Malassezia furfur. In contrast, Trichophyton rubrum is a dermatophyte that causes tinea infections of keratinized tissues (like feet or nails), Candida albicans causes candidiasis, and Aspergillus fumigatus causes aspergillosis; none of these produce tinea versicolor. Diagnostic clues can include spaghetti-and-meatballs appearance on KOH prep and a copper-orange fluorescence under Wood’s lamp, reflecting Malassezia’s pigment-related byproducts.