skin disorders
Seborrheic Dermatitis
Introduction
Seborrheic dermatitis is chronic inflammation that causes yellow, greasy scales and dandruff to form on areas of the skin that have a high number of oil glands such as the scalp and face, along the hairline, around the ears, and occasionally on other areas. (See also Overview of Dermatitis .) The cause of seborrheic dermatitis is unknown, but the number ofMalasseziayeasts, an organism normally present on the skin, and a person's reaction to them play some role. Seborrheic dermatitis occurs most often in infants, usually within the first 3 months of life, and in adults 30 to 70 years old. The risk and severity of the disorder seems to be affected by genetic factors, often runs in families, and is worse in cold weather. Seborrheic dermatitis may be more common and more severe among people who have a neurologic disorder (especially Parkinson Disease (PD) ) and among people who have 