Pityriasis Versicolor : A fungal infection of skin

Pityriasis versicolor is a mild, chronic, asymptomatic infection of the most superficial layers of the skin caused by fungus called Pityrosporum orbiculare. It is very common in warm and humid climate and usually affects young adults.

It is characterized by fine, scaly pigmentatation which may be hypo or hyperpigmentation. The macules may vary in size and shape and usually appear on trunk, upper arm, shoulder and neck. Macules may become confluent to form polycyclic patches



Diagnosis of pityriasis versicolor

The diagnosis is done by examination of the patches and a microscopic examination of the skin scrapping is done in a KOH preparation. This reveals short hyphae and cluster round and budding yeast cells. Scaly lesion usually show golden yellow fluorescence when examined under wood’s light.



Treatment of Pityriasis versicolor

The treatment includes selenium sulphide shampoo in 2.5% solution. Ideally it should be applied to the affected part in the night and should be washed off in the morning. Other antifungal ointments like miconazole or clotriazole can be applied twice daily and is effectrive if used regularly for 10 to 14 days. In extensive and lond standing stubborn eruptions oral antifungals like ketokonazole 200 to 400 mg per day of fluconazole 150mg weekly may be effective.

The patient may have to take treatment for 2 to 3 months in extensive lesions.