Dandruff is a skin condition characterized by loose, greasy or dry, white to yellowish scales, with or without associated reddened skin. In infants, it is refered to as cradle cap. Another term used for dandruff is seborrheic dermatitis. Dandruff may affect the skin of the scalp, eyebrows, eyelids, nasolabial creases, lips, behind the ears, in the external ear, and the skin of the trunk, particularly over the sternum and along skin folds.
Dandruff is believed to run in families. Stress, fatigue, weather extremes, oily skin, infrequent shampoos or skin cleaning, use of lotions that contain alcohol, skin disorders, or obesity may increase the risk. Dandruff can also be asociated with neurologic conditions, including Parkinson's disease, head injury, and stroke, as well as human immunodeficiency virus (HIV).
