What is seborrheic dermatitis?

Seborrheic dermatitis is a common skin problem that forms flakes or scales on oil-producing areas of the skin. Seborrheic dermatitis can affect individuals of any age. In infants, seborrheic dermatitis is often called cradle cap, which forms a characteristic flaky skin rash that covers the scalp. Seborrheic dermatitis can also affect older adults, usually affecting oily areas such as the scalp, nose, ears, and near skin folds of the chest and back.