Tinea versicolor, also known as pityriasis versicolor, is a common fungal infection of the skin that causes small, discolored patches on the skin. The condition is caused by an overgrowth of yeast on the skin, which can be exacerbated by warm and humid conditions.

Tinea versicolor usually appears on the chest, back, and upper arms as small, scaly patches that can be white, pink, or brown in color. The patches may be more noticeable after exposure to sunlight, as the affected skin does not tan in the same way as the surrounding skin.

Diagnosis of tinea versicolor may involve a physical examination of the affected skin and a skin scraping test to look for the presence of the yeast under a microscope.

Treatment for tinea versicolor typically involves antifungal medications applied to the skin, such as topical creams or shampoos. In some cases, oral antifungal medications may also be prescribed. It is important to follow the treatment regimen prescribed by a healthcare professional to ensure that the infection is fully treated.

Prevention of tinea versicolor can be achieved by keeping the skin clean and dry, avoiding tight-fitting clothing, and avoiding prolonged exposure to hot and humid environments. People who are prone to tinea versicolor may also benefit from using antifungal soaps or shampoos on a regular basis.

The fungus that causes tinea versicolor can be found on healthy skin. It only starts causing problems when the fungus overgrows. A number of factors may trigger this growth, including:

• Hot, humid weather
• Oily skin
• Hormonal changes
• Weakened immune system

To help prevent tinea versicolor from returning, your doctor can prescribe a skin or oral treatment that you use once or twice a month. You may need to use these just during warm and humid months. Preventive treatments include:

• Selenium sulfide (Selsun) 2.5 percent lotion or shampoo
• Ketoconazole (Ketoconazole, Nizoral, others) cream, gel or shampoo
• Itraconazole (Onmel, Sporanox) tablets, capsules or oral solution
• Fluconazole (Diflucan) tablets or oral solution

If tinea versicolor is severe or doesn't respond to over-the-counter antifungal medicine, you may need a prescription-strength medication. Some of these medications are topical preparations that you rub on your skin. Others are drugs that you swallow. Examples include:

• Ketoconazole (Ketoconazole, Nizoral, others) cream, gel or shampoo
• Ciclopirox (Loprox, Penlac) cream, gel or shampoo
• Fluconazole (Diflucan) tablets or oral solution
• Itraconazole (Onmel, Sporanox) tablets, capsules or oral solution
• Selenium sulfide (Selsun) 2.5 percent lotion or shampoo

Even after successful treatment, your skin color may remain uneven for several weeks, or even months. Also, the infection may return in hot, humid weather. In persistent cases, you may need to take a medication once or twice a month to prevent the infection from recurring.