Tinea Versicolor: Causes, Diagnosis, and Treatment - Verywell Health
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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 (OTC) antifungal products, although it can take some time for skin color to return to normal. Tinea versicolor is most common in teenagers and young adults but isn't contagious.
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Symptoms
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 it comes back with the return of hot, humid weather.
Sun exposure may make tinea versicolor more obvious because the affected areas won't tan.
The infection usually develops on the back, chest, and shoulders, but it can also appear on the arms, neck, and face. Other symptoms of tinea versicolor include mild itching and dryness or scaliness.
Causes
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 results 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 (an excess of the hormone cortisol in the blood)
- 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.
Diagnosis
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 (skin loses melanocytes)
- Syphilis (bacterial infection spread by sexual contact)
- Pityriasis rosea (rash of raised, red scaly patches)
- Pityriasis alba (rash of light-colored scaly patches)
- Eczema (inflamed, itchy, cracked skin)
- Psoriasis (chronic skin disease caused by an immune system disorder)
- Seborrheic dermatitis (scaly patches mainly on the scalp and oily areas of the body, including the face and chest)
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, which stands for postassium (K), oxygen (O), and hydrogen (H), can confirm the rash's characteristic "spaghetti and meatballs" appearance beneath the microscope.
- The Wood's light, or Wood's lamp, 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.
Treatment
Tinea versicolor almost always can be effectively eradicated with a topical OTC antifungal soap, shampoo, or cream. Zinc pyrithione 1% shampoo, which is easier to find than the soap, is also effective against tinea versicolor.
Among the most common such products are:
- Lotrimin AF (clotrimazole)
- Selsun Blue (selenium sulfide)
- Zinc pyrithione soap or shampoo
- 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.
Note that even though treatment kills the pathogenic yeasts, skin discoloration can persist for weeks or months until melanocytes are able to produce melanin again.
Tinea versicolor has a recurrence rate of around 80% after two years, and 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.
A Word From Verywell
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.
Frequently Asked Questions
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Tinea versicolor is caused by an overgrowth of a specific type of yeast that produces a chemical that turns off melanocytes. Factors that can contribute to yeast overgrowth include Cushing's disease, pregnancy, hormonal contraception, malnutrition, burns, steroid therapy, and hot weather.
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Antifungal soaps, shampoos, and creams are used to treat tinea versicolor. Over-the-counter products that are effective include Lotrimin, Selsun Blue, Monistat, Lamisil, and zinc pyrithione.
If OTC treatments do not work, your healthcare provider can prescribe an oral anti-fungal medicine, such as Diflucan (fluconazole), or prescription creams like Nizoral (ketoconazole).
Once healed, you may need to repeat the treatment once a month or more to keep tinea versicolor from coming back.
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Antifungal treatments can clear up the underlying fungus infection from tinea versicolor in a week or two. However, it will take longer for the skin to return to its normal color. The discoloration can last for up to six months until the melanocytes of the skin are able to produce melanin again.
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