Tinea versicolor

Anatomy or system affected: Skin

Also known as: Pityriasis versicolor

Definition

Tinea versicolor is a type of dermatomycosis that is caused by a yeast that interferes with normal tanning. Dermatomycosis includes a variety of superficial skin infections caused by fungi or yeast. These types of infections almost always only affect skin, hair, and nails. In people with severe immune problems, these infections can become more serious and invasive.

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Tinea versicolor can result in uneven skin color and usually affects the back, upper arms, underarms, chest, and neck. It rarely affects the face.

Causes

The fungus that causes tinea versicolor, Malassezia furfur, is normally present in small numbers on the skin and scalp. Overgrowth of the yeast leads to infection.

Risk Factors

Risk factors for tinea versicolor include age (more common in adolescents and young adults), gender (more common in boys and men), skin condition (more common in people with naturally oily or excessively sweaty skin), and climate (more common in warm and humid climates).

Symptoms

Symptoms include uneven skin color, with either white or light brown patches; light scaling on affected areas; slight itching that is worse when the person is hot; and patches that are most noticeable in summer months.

Screening and Diagnosis

A doctor will ask about symptoms and medical history and will perform a physical exam. The patient may be referred to a dermatologist, a specialist in skin disorders and conditions. The doctor may use an ultraviolet light to see the patches more clearly and may scrape the patch for testing.

Treatment and Therapy

Treatment options for tinea versicolor include topical medications such as selenium sulfide lotion (2.5 percent) or shampoo (1 percent; such as Dandrex, Exsel, and Selsun Blue), applied daily for one week and then monthly for several months to prevent recurrences. Another option is oral medication, such as prescription antifungal drugs. Oral medications make treatment shorter, but they are more expensive and associated with more adverse side effects.

Once the infection is successfully treated, the patient’s skin will naturally return to its normal color. However, this process usually takes several months. Also, the condition may improve in the winter only to return again in the summer months.

Prevention and Outcomes

One should avoid excessive heat and sweating to reduce the risk of tinea versicolor.

Bibliography

American Academy of Dermatology. “Tinea Versicolor.” Available at http://www.aad.org.

Berger, T. G. “Dermatologic Disorders.” In Current Medical Diagnosis and Treatment 2011, edited by Stephen J. McPhee and Maxine A. Papadakis. 50th ed. New York: McGraw-Hill Medical, 2011.

National Library of Medicine. “Tinea Versicolor.” Available at http://www.nlm.nih.gov/medlineplus/ency/article/001465.htm.

Richardson, Malcolm D., and Elizabeth M. Johnson. The Pocket Guide to Fungal Infection. 2d ed. Malden, Mass.: Blackwell, 2006.