An Overview of Tinea Versicolor

Tinea versicolor, also known as pityriasis versicolor, is a superficial fungal infection caused by an overgrowth of yeast that occurs naturally on the skin. The rash that develops is characterized by distinct patches of discolored skin and mild itching that can be effectively treated with over-the-counter antifungal products, although it can take some time for skin color to return to normal. It's most common in teenagers and young adults but isn't contagious.

The tell-tale symptom of tinea versicolor is a rash that appears as small flat patches of discolored skin with defined borders. The rash may be hypopigmented (lighter than the surrounding skin) or hyperpigmented (darker than the surrounding skin), in shades ranging from white, red, pink, or brown.

Patches of tinea versicolor rash can slowly increase in size to join with nearby spots to create large areas of discolored skin. Sometimes the spots diminish or disappear during the cooler seasons, but come back with the return of hot, humid weather.

The infection most often develops on the back, chest, and shoulders, but can also appear on the arms, neck, and face. Other symptoms of tinea versicolor include mild itching and dryness or scaliness.

The yeasts that cause tinea versicolor belong to the Malassezia family, including Pityrosporum orbiculare and Pityrosporum ovale. These yeasts exist naturally on the outer layer of skin (stratum corneum) and hair follicles of normal, healthy skin.

Though generally harmless, these yeasts can sometimes experience overgrowth and convert into their pathogenic mycelial phase known as Malassezia furfur, resulting in the outbreak of the rash.

Hypopigmentation occurs when the yeast produces a chemical that turns off melanocytes—special skin cells that produce melanin, the pigment responsible for skin, eye, and hair color. Hyperpigmentation is the result of inflammation caused by the fungal infection.

There are a number of things that lead to yeast overgrowth, including:

• Removal of the adrenal gland
• Cushing's disease
• Pregnancy
• Hormonal changes
• Malnutrition
• Burns
• Steroid therapy
• Suppressed immune system
• Oral contraceptives
• Hot, humid weather
• Oily skin

Tinea versicolor can occur at any age but is most common in adolescence and early adulthood (a time when the sebaceous glands are particularly active). It's also commonly seen in tropical and semi-tropical climates.

Most cases of tinea versicolor can be diagnosed by a doctor based on the appearance of the rash, although it can sometimes be confused with a number of other rashes, including:

• Vitiligo
• Syphilis
• Pityriasis rosea
• Pityriasis alba
• Eczema
• Psoriasis
• Seborrheic dermatitis

When additional testing is necessary to differentiate tinea versicolor from other rashes, the diagnosis can be confirmed with any of several tests:

• A KOH test can confirm the rash's characteristic "spaghetti and meatballs" appearance beneath the microscope.
• The Wood's light examination will make the yeast glow a pale yellow beneath a black light.
• Fungal cultures, while infrequently used, can confirm infection by growing the fungus on a culture medium.

Tinea versicolor almost always can be effectively eradicated with a topical, over-the-counter (OTC) antifungal soap, shampoo, or cream.

Among the most common such products are:

• Lotrimin AF (clotrimazole)
• Selsun Blue (selenium sulfide)
• Zinc pyrithione soap
• Monistat (miconazole)
• Lamisil (terbinafine)

For cases of tinea versicolor that are especially severe or that don't respond to OTC treatments, prescription medications may be required. Oral antifungals such as Diflucan (fluconazole) as well as prescription antifungal creams and shampoos, such as Nizoral (ketoconazole), are among the options often used.

Tinea versicolor has a recurrence rate of around 80% after two years and so re-treatment may be needed. For people who are prone to developing tinea versicolor, regular use of an antifungal soap or wash can help prevent the rash from recurring. Once a month is customarily recommended but some people may need to use antifungal products more often, especially in the warm weather months.

Although tinea versicolor is a benign skin condition, people who have it often feel self-conscious about the skin discoloration it causes. The best way to deal with any embarrassment caused by this rash is to take steps to prevent it from worsening until the skin returns to normal.

The first of these is the be highly vigilant about sun protection. Any degree of tanning can exacerbate the contrast between the tanned skin and skin affected by the rash.

Equally important is to steer clear of oily body lotions or creams, as oil can make the rash worse. For sunscreen, choose a product that is labeled oil-free or noncomedogenic.