Infection Of The Skin

This disease is caused by Pityrosporum orbiculare, a gram-positive yeast-like microorganism that is usually a skin commensal. In some individuals, the organism can become pathogenic. Pityrosporum versicolor often affects young adults, causing brown scaly macules on the trunk and sometimes on the limbs. Carboxylic acids released by the organisms inhibit melanogenesis and thus the affected areas may appear relatively pale following exposure to sunlight. The infection may be demonstrated by...