Pityriasis versicolor is a fungal skin infection caused by a type of yeast. It's a common cause of skin rash in teens and young adults. It causes lots of round and oval-shaped patches on the skin, especially on the chest, back, and upper arms.
It's also called tinea versicolor.
Pityriasis versicolor (pit-uh-RYE-uh-sis vur-si-KUL-ur) skin patches usually are on the torso and upper arms. But they can also appear on the face and neck, especially in younger kids. The patches can be white, brown, red, or pink.
The patches are dry, flaky, or scaly, and can be flat or slightly raised. They may be a little itchy but often aren't felt at all. They can start off small and round, then join together to make much larger patches.
The yeast prevents the skin from tanning, so the patches can look lighter than the surrounding skin, especially in the summer. A person might be bothered by their appearance or not even notice them.
Pityriasis versicolor is caused by a type of yeast that normally lives on the skin. When the environment it lives in gets warm and moist, it can grow out of control and cause symptoms.
Pityriasis versicolor is not contagious.
Hot, humid weather and lots of sweating can create a warm, moist environment for the yeast to overgrow. This is why the infection is more common in tropical countries. The yeast also likes an oily environment, so oily skin can play a part (and of course, teens and young adults can have oily skin).
Sometimes pityriasis versicolor runs in families. It's also more likely to affect people who have a weakened immune system or who are malnourished.
Doctors often can diagnose pityriasis versicolor just by looking at it. They'll also ask about the symptoms and the child's lifestyle. Sometimes a doctor will scrape off a small sample of the flaky infected skin to look at under a microscope or to test in a lab.
Over-the-counter (OTC) antifungal creams, lotions, or shampoos (used as a body wash) may solve a mild infection. More serious infections may need prescription medicine, either applied to the skin or takens as a pill or syrup.
Treatment usually takes 1 to 4 weeks. Sometimes the infection comes back. If that happens, treatment is repeated.
Pityriasis versicolor usually clears up quickly with treatment. But the skin patches may stay discolored for weeks or months. To make them less noticeable, it's important to use sunscreen to prevent the skin from tanning or burning.
Someone who keeps getting pityriasis versicolor might need to repeated, regular treatment (weekly or monthly) to prevent further infections.
Reviewed by: Elana Pearl Ben-Joseph, MD
Date Reviewed: Mar 27, 2018
