Which organism is associated with tinea versicolor and was formerly known as Pityrosporum?

• A. Microsporum canis
• B. Malassezia species
• C. Candida albicans
• D. Trichophyton rubrum

Answer: (B)

Tinea versicolor is caused by a lipophilic yeast that normally lives on the skin but overgrows in oily, warm, humid conditions, producing the pigment changes and fine scaling seen in this condition. These yeasts were historically grouped under the genus Pityrosporum, with old names like Pityrosporum ovale, but they have since been reclassified as Malassezia species. So the organism associated with tinea versicolor and formerly known as Pityrosporum is Malassezia species. The other organisms listed cause different infections—dermatophyte skin infections or candidiasis—not tinea versicolor.