Seborrheic dermatitis is a skin disease. This has white or yellowish scales in areas more body fat as the face, scalp or inside the ear. If seborrheic dermatitis affects infants is called cradle cap.
Currently, not the cause of seborrheic dermatitis is known. It seems to be hereditary but can also be caused by hormone levels, weak immune system, lack of nutrients or that the origin of the scales is a fungus called Malassezia.