Cradle cap is the term used when seborrheic dermatitis affects the scalp of infants.
Causes and Risks Seborrheic dermatitis may involve 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. The cause is unknown. Seborrheic dermatitis appears to run in families. Stress , fatigue , weather extremes, oily skin , infrequent shampoos or skin cleaning, use of lotions that contain alcohol, or skin disorders such as acne or obesity may increase the risk. Neurologic conditions, including Parkinson's disease , head injury , and stroke can also be associated with seborrheic dermatitis.