Monday, April 1, 2013

Tinea Versicolor


Overview
Tinea versicolor, also known as pityriasis versicolor, is a common non-cancerous (benign) skin condition caused by surface (superficial) infection with a yeast that commonly lives on the skin. In the right conditions, such as warm, oily, and moist skin, the yeast (Malassezia) can overgrow and cause a rash consisting of tan, pink, brown, or white flaky patches. Although it is an infection, tinea versicolor is not contagious, as the yeast is found commonly in the environment.

Who's At Risk
Tinea versicolor can develop in people from adolescence and beyond, of all races, and of either sex.

However, tinea versicolor is most commonly found in tropical areas with high humidity and high temperatures. In milder climates, teens and young adults are affected most frequently. Tinea versicolor is uncommon in young children or in adults older than 65.

Some conditions make tinea versicolor more likely to occur:
  • Living in a warm, humid climate
  • Having oily skin
  • Sweating frequently or excessively
  • Using corticosteroids (cortisone)
  • Taking medications that weaken the immune system
Signs and Symptoms
The most common locations for tinea versicolor include:
  • Chest and upper back
  • Upper arms
  • Abdomen
  • Neck
  • Thighs
Tinea versicolor appears as many white, pink, salmon-colored, tan, or brown patches ranging in size from 1 to 3 cm. The individual lesions can join together to form large patches. Most lesions have a very fine, flaky surface (scale).

The yeast that causes the condition produces a substance that can temporarily bleach the underlying skin to a lighter color. Even after the infection has gone away, the spots may be visible as lighter (hypopigmented) patches on the skin that may not get their normal color back for many months. These hypopigmented spots do not tan normally. The hypopigmented areas are more obvious in darker-skinned people. 

Even if the color has not returned to normal after treatment, the flakiness of the skin should have resolved.

Tinea versicolor does not usually cause any symptoms, though some people report minor itching, especially when they get sweaty.

Self-Care Guidelines
If you suspect that you have tinea versicolor, you might try an over-the-counter antifungal cream such as terbinafine, clotrimazole, or miconazole. An over-the-counter shampoo containing selenium sulfide can be used as a lotion by applying it to the affected areas overnight and rinsing it off in the morning. However, if the condition does not seem to be getting better after 2 weeks of daily treatment, see a dermatologist or another physician for evaluation.

If you have been treated for tinea versicolor, avoid wearing tight, restrictive clothing. Also, sun exposure may make the light-colored areas more apparent, so avoid sun exposure or wear sunscreen until the spots have returned to their normal color.
When to Seek Medical Care
If the above self-care measures do not work or if you develop a rash all over that seems to be getting worse, see your doctor.
Treatments Your Physician May Prescribe
To confirm the diagnosis, your physician might scrape some of the surface skin material (scales) onto a glass slide and examine them under a microscope. This procedure, called a KOH (potassium hydroxide) preparation, allows the doctor to look for tell-tale signs of yeast infection.

Once a diagnosis of tinea versicolor has been confirmed, the physician may recommend one of the following treatments:
  • Selenium sulfide lotion (or shampoo, which can be used as a lotion and then rinsed off)
  • Pyrithione zinc shampoo (used as a lotion and then rinsed off)
  • Antifungal cream or lotion such as ketoconazole, econazole, oxiconazole, or ciclopirox
  • Antifungal pills such as ketoconazole, fluconazole, or itraconazole
Recurrence of the infection after treatment is common. Because some people are more likely than others to get the infection, your doctor may recommend a preventive or maintenance treatment to use during the warmer, more humid months, consisting of antifungal cream, lotion, or shampoo, applied every week or two.



References

Bolognia, Jean L., ed. Dermatology, pp.989, 1171-1174. New York: Mosby, 2003.

Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.2014-2016. New York: McGraw-Hill, 2003.

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