Tinea versicolor is a skin disorder caused by an overgrowth of a fungus that lives normally on the skin. It shows up as scaling and bumps primarily on the chest, shoulders, and back. It can make dark skin appear lighter and light skin appear brownish.
Tinea versicolor occurs when a fungus that lives normally on the skin starts to multiply rapidly. The overgrowth of the fungus causes skin that is uneven in color, along with a buildup of scaly patches.
Tinea versicolor is caused by an overgrowth of a fungus that grows normally on people's skin. No one knows why the overgrowth occurs in some people and not in others. Risk factors that increase a person's chance of developing tinea versicolor include: