Tinea Versicolor

What Is It?

Many microorganisms normally live on our skin, including a group of yeast species called Malassezia. (Round or oval yeasts in this group were previously known by the names Pityrosporum orbiculare and Pityrosporum ovalis.) The yeast lives in our pores. Under certain conditions, it can shift its form from a round or oval yeast shape to a string-like, branching shape. These branching yeasts are named hyphae. They can migrate under the skin and they produce azelaic acid, a substance that can change the amount of pigment (color) in new skin cells. In its hyphae form, the yeast causes a rash called tinea versicolor, also called pityriasis versicolor.

Tinea versicolor is common year-round in the tropics and subtropics and is seen in the summer months in more temperate climates. Sun exposure, use of oils on the skin, naturally oily skin and sweating are all suspected to be triggers that can cause the round or oval yeast to convert to its hyphae form, beginning the infection and rash. The rash can spread between people who have skin contact.

The rash occurs more often in teenagers and young adults and appears on the back, neck, upper chest, shoulders, armpits and upper arms. Most people who get this rash are in good health. However, tinea versicolor is more likely to occur if you have a suppressed immune system, for instance, if you are taking a corticosteroid medication such as prednisone for another health problem. It is also more common in women who are taking birth control pills and in pregnant women.

Symptoms

The skin rash is made up of scattered pink, tan, brown or white marks on the skin. Each person will get only one of the colors. These marks are usually flat, without texture. They may be small round spots or areas that start smaller then get larger and combine with other areas. The skin may flake at the edge of the rash spots. The rash may be itchy, especially when a person is hot or sweaty.

The skin spots may be more obvious after skin has been exposed to the sun, because these areas do not tan evenly.

Diagnosis

Your doctor may shine a black light (ultraviolet light) on the rash. Yeast types in the Malassezia group may glow yellow-green under the light, which would confirm the diagnosis. Your doctor also can examine skin scrapings under the microscope to see if the yeast is present.

Expected Duration

The yeast responds well to treatment in most people, but the changes in skin color may remain for several months, especially if you have spent time in the sun. Wearing a strong sunscreen and taking other precautions against sun exposure can minimize the difference in skin color between normal skin and skin affected by tinea versicolor.

Prevention

Because the rash occurs more readily in hot, humid conditions, keep your skin as dry and cool as possible when you are in this climate. Tinea versicolor can be spread through skin-to-skin contact or by coming in contact with contaminated articles such as towels, clothing or bedding.

The tinea versicolor rash continues to return in 40% to 60% of people. If you have had more than one episode of tinea versicolor, skin treatment every two weeks with a shampoo that destroys yeast (such as anti-dandruff shampoos that contain selenium sulfide) can usually prevent the rash from recurring. This may be especially helpful prior to travel to a tropical climate or during months with warm weather. Another option is to take antifungal medicines by mouth to prevent the rash from returning.

Treatment

Topical treatments including anti-dandruff shampoos containing selenium sulfide (Selsun), ketoconazole shampoo (Nizoral), terbinafine spray (Lamisil) and antifungal creams and oral medications (ketoconazole [Nizoral], itraconazole [Sporanox], fluconazole [Diflucan]) are available to treat tinea versicolor. Topical treatments usually are used one or two times each day. Treatment can last days or weeks, depending on how the rash responds. For six months after your original treatment, you may be advised to apply topical treatments occasionally or take one or more doses per month of oral antifungal medicine to help prevent the rash from returning.

Doctors commonly recommend that you wash bed linens and pajamas daily during treatment to avoid reinfection. Some experts recommend boiling or discarding contaminated clothing if the rash is persistent, believing this is a more certain way to eliminate the yeast.

When To Call A Professional

If you have a skin rash that you think may be tinea versicolor, you should make an appointment with your doctor to have the rash evaluated.

Prognosis

There are no serious complications from tinea versicolor. In most people, the rash goes away with treatment. However, it takes several months for the skin to return to its normal appearance. The rash returns after treatment within six months in 40% to 60% of people who don't use antifungal treatments from time to time to suppress the rash.

Additional Info

American Academy of Dermatology

930 E. Woodfield Rd.

Schaumburg, IL 60173-4927

Phone: (847) 330-0230

Toll-Free: (888) 462-3376

Fax: (847) 330-0050

http://www.aad.org/