Main Page | See live article | Alphabetical index Tinea versicolor, also known as pityriasis versicolor is a relatively common skin infection caused by the fungus Pityrosporum orbiculare, a type of yeast. This fungus is considered part of the normal flora (microorganisms that normally occur) on human skin and only becomes troublesome under certain circumstances. The most commonly affected sites are the back, underarm, upper arms, chest, and neck. The typical lesion is a flat discoloration with a sharp border and fine scales. The lesions are typically dark tan with a reddish cast. In African Americans, pigmentary changes are common with hypopigmentation (loss of color) or hyperpigmentation (increase in skin color). Itching may be present. Tinea versicolor is more common in hot climates and is associated with increased sweating. It occurs more commonly in adolescents and young men. Symptoms Persistent patches of discolored skin Often dark tan with a reddish cast Has sharp borders Has fine scales Most common sites: back, underarm, upper arm, chest, neck Most common in adolescent and young adult males Associated with hot climates Associated with increased sweating Itching External link NIH guide to Tinea versicolor This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.