Tinea versicolor, also known as pityriasis versicolor, is a common benign superficial fungal infection of the skin. The infective organisms are dimorphic yeast of the Malassezia genus (Malassezia globosa, Malassezia furfur, and Malassezia sympodialis). The yeast forms of these organisms are part of the normal skin flora; however, conversion to the filamentous hyphal form leads to the appearance of tinea versicolor.

Clinically, the infection manifests as asymptomatic macules, papules, patches, and plaques of varying pigmentation with fine scale. It typically occurs in a seborrheic distribution including the upper trunk, arms, neck, suprapubic skin, and to a lesser extent, the face.

The distribution is worldwide, but it is most commonly found in tropical areas with high humidity and temperatures. It typically begins during or just after the warmest months of the year and may last from weeks to months. Young adults and teenagers seem to be affected more frequently due to increased sebaceous gland activity. Tinea versicolor is uncommon in young children, but atypical variants presenting on the scalp, face, and neck of children have been reported, and most are hypopigmented.

Tinea versicolor is not contagious. Factors mediating its development include heat, humidity, oral contraceptives, corticosteroid use, hyperhidrosis, diabetes (type 1, type 2), and immune suppression. Individuals with oily skin or a positive family history may be more susceptible.