Seborrheic dermatitis is the single most common rash of adult human beings. When it occurs in infancy, it is commonly called cradle cap. The adult disease tends to favor the scalp, skin behind the ears, forehead, brows, nasolabial folds of the face, mid-chest area, and the mid-back, producing an itchy, red scaling dermatitis. The scaling in the scalp can be conspicuous, producing impressive dandruff. The cause of this condition is unclear, but it responds well to topical steroids and to topical antifungal creams. Medicated shampoos containing tar, selenium sulfide, and zinc pyrithione are often effective. This condition commonly improves spontaneously but will ultimately recur. There is no cure so treatment must continue indefinitely.