Tinea versicolor or pityriasis versicolor is a common skin infection caused by the yeast Malassezia furfur or Pityrosporum orbiculare. This yeast is normally found on the human skin and only becomes troublesome under certain circumstances, such as a warm and humid environment. It is occasionally referred to by its colloquial Hawaiian moniker, "haole rot".

Symptoms

The symptoms of this condition include:

• Generally oval or irregularly-shaped spots of 1/4 to 1 inch in diameter, often merging together to form a larger patch
• Occasional fine scaling of the skin producing a very superficial ash-like scale
• Pale, dark tan, or pink in color, with a reddish undertone that can darken when the patient is overheated, such as in a hot shower or during/after exercise
• Sharp border
• Itching that can worsen with sweating or overheating

These spots commonly affect the back, underarm, upper arm, chest, lower legs, and neck. Occasionally it can also be present on the face. The yeasts can often be seen under the microscope within the lesions and typically have a so called "spaghetti and meat ball appearance" as the round yeasts produce filaments.

In people with dark skin tones, pigmentary changes such as hypopigmentation (loss of color) are common, while in those with lighter skin color, hyperpigmentation (increase in skin color) are more common. These discolorations have led to the term "sun fungus".

Prevalence

Tinea versicolor is a common condition. It is estimated that 2 to 8% of the population of the United States has it. This skin disease commonly affects adolescents and young adults, especially in warm and humid climates. It is thought that the yeast feeds on skin oils (lipids) as well as dead skin cells.

Treatment

Treatments for tinea versicolor include:

• Topical antifungal medications - containing either 2.5% selenium sulfide (Selsun shampoo in UK, but not Selsun Blue which contains only 1%) or 2% ketoconazole (Nizoral ointment and shampoo) applied to dry skin and washed off after 10 minutes, repeated daily for 2 weeks. Other topical antifungal agents such as clotrimazole, miconazole or terbinafine are less widely recomended.
• Oral antifungal prescription only medications include 400 mg of ketoconazole or fluconazole in a single dose, or ketoconazole 200 mg daily for 7 days, or itraconazole 400 mg daily for 3-7 days.
• Recurrence is common and may be reduced by intermittent application of topical agents or adding a little anti-dandruff shampoo to the bath water.

External links

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• Health in Plain English - Tinea versicolor (with pictures)

Infectious skin diseases | Fungal diseases

Pityriasis versicolor | Pityriasis versicolor | Pityriasis versicolor | Łupież pstry | Pitiríase versicolor