Tinea versicolor (pityriasis versicolor) is a fungal or yeast skin rash. It's caused by too much growth of a certain yeast on the skin. It causes patches on the skin that are lighter or darker than your normal skin color. The patches most often occur on the chest or back. They also stop the skin from tanning evenly and often appear as lighter spots on tan skin. After treatment, it might take several months for your skin color to return to normal.

Everyone has this yeast on their body. So this rash is not contagious to others. It can't be spread if someone touches it. You don't have to worry about exposing others at work or school.

Yeast is a type of fungus that normally lives on the skin. This condition happens when the yeast grows too much. Researchers don't know why some people get this rash and others don't.

You are more at risk for tinea versicolor if you:

• Live in a hot, humid climate.
• Have moist or oily skin.
• Have a weak immune system.

Symptoms can be a bit different in each person. The most common symptom is patches on the skin that may look white, pink, or light brown. The patches may also look dry or scaly. The rash is often on the neck, upper back, chest, and shoulders. The patches are most easily seen in the summer because they don't darken in the sun. You may have mild itching, especially if you get hot. The patches can grow in heat or humidity, or if you are on steroid therapy or have a weak immune system.

The symptoms of tinea versicolor can look like other health conditions. See your doctor for a diagnosis.

Your doctor will ask about your symptoms and health history. You'll have a physical exam. The exam will include looking closely at your skin. Your doctor may use an ultraviolet light called a Wood's lamp to see the patches more clearly.

You may also have a skin scraping. The doctor scrapes the top of your skin with a small tool. The scraped tissue is examined with a microscope to look for the yeast.

The rash is treated with antifungal or medicated dandruff shampoo on the skin. Use the shampoo over your whole body in the shower. Let the shampoo stay on for a few minutes before rinsing it off. Don't use soap afterward. Do this every day for 4 weeks.

Your doctor may also prescribe antifungal cream or oral antifungal medicine to take by mouth. They may advise you to use over-the-counter miconazole or clotrimazole cream. Use this 2 times a day for 7 days.

Your skin may only get better for a short time. Then the rash may happen again. You may need to use the shampoo each month to keep it from coming back. It may take several months for your skin to return to its normal color.

Talk with your doctor about the risks, benefits, and possible side effects of all medicines.

This fungus can come back again after treatment. If you have recurrences, you may need to use shampoos or medicines. To help prevent the rash from returning, use medicated dandruff shampoo over your whole body when in the shower. Do this once a month for the next year. It's very important to do this in the summertime. That is when the rash is most likely to come back.

Also make sure to:

• Avoid using skin products that are oily.
• Stay out of hot, humid weather.
• Stay away from things that cause a lot of sweating.
• Wear loose clothing to let your skin stay cool and dry.

Call your doctor if:

• Your symptoms don't get better, or get worse.
• You have new symptoms.
• You have a fever of 100.4°F (38°C) or higher, or as directed by your doctor.

• Tinea versicolor is a fungal skin rash. It's caused by too much growth of a normal yeast on the skin.
• The most common symptom is patches on the skin that may look white, pink, or light brown. They may also look dry or scaly.
• The rash is usually on the neck, upper back, chest, and shoulders.
• It is not spread from person to person.
• The rash is treated with antifungal or medicated dandruff shampoo on the skin.
• Your skin may only get better for a short time. Then the rash may happen again. You may need to use the shampoo each month to keep it from coming back.
• It may take several months for your skin to return to its normal color.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new directions your doctor gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose of that visit.
• Know how you can contact your doctor if you have questions.