Seborrheic dermatitis is a common condition that makes the skin look greasy, scaly and flaky. It usually affects the scalp. In adolescents and adults, seborrheic dermatitis is commonly called "dandruff." In babies, it is known as "cradle cap." Seborrheic dermatitis can also affect the skin on other parts of the body, such as the face and chest, and the creases of the arms, legs and groin.
Seborrheic dermatitis is common in babies younger than 3 months of age and in adolescents and adults. In adults, it's more likely to affect men than women.
Doctors don’t know the exact cause of seborrheic dermatitis. The cause may be different in infants and adults. Seborrheic dermatitis may run in families. The condition seems to be related to hormones, because the disorder often appears in infancy and disappears before puberty. Or the cause might be a fungus, called malassezia. This organism is normally present on the skin in small numbers, but sometimes its numbers increase, resulting in skin problems.
Seborrheic dermatitis has also been linked to neurologic disorders such as Parkinson's disease and epilepsy. The reason for this relationship isn't known.
The treatment of seborrheic dermatitis depends on its location on the body. Treatment also depends on your age.
Seborrheic dermatitis of the scalp (dandruff) in adults and adolescents. Dandruff is usually treated with a shampoo that contains salicylic acid (some brand names: Scalpicin, X-Seb), selenium sulfide (brand names: Exsel, Selsun Blue) or zinc pyrithione (some brand names: DHS Zinc, Head & Shoulders). These shampoos can be used 2 times a week. Shampoos that contain coal tar (some brand names: DHS Tar, Neutrogena T/Gel, Polytar) may be used 3 times a week. If you have dandruff, you might start by using one of these shampoos daily until your dandruff is controlled, and then use it 2 or 3 times a week.
When you use a dandruff shampoo, rub the shampoo into your hair thoroughly and let it stay on your hair and scalp for at least 5 minutes before rinsing. This will give it time to work.
If the shampoo alone doesn't help, your doctor might want you to use a prescription steroid lotion once or twice daily.
Seborrheic dermatitis of the skin creases in adolescents and adults. Steroid lotions may be used in adolescents and adults.
Seborrheic dermatitis of the scalp (cradle cap) in babies. Seborrheic dermatitis of the scalp in babies is treated with products that are not as strong as those used in adults. You might start with a mild, nonmedicated baby shampoo. Using mineral oil, olive oil or petrolatum jelly can help loosen the scales.
Brushing your baby's scalp with a soft brush, like a toothbrush, can help loosen scales or flakes. But be gentle when massaging or brushing your baby's scalp--a break in the skin makes it vulnerable to infection. If a nonmedicated shampoo doesn't work, talk to your doctor about switching to a shampoo that contains tar. Or your doctor may recommend a prescription shampoo that contains 2% ketoconazole (brand name: Nizoral). This condition usually resolves in a few months.
Seborrheic dermatitis of the skin creases in babies. Gentle steroid lotions or creams may be used to treat seborrheic dermatitis in the skin creases of babies. Be sure to talk to your family doctor about the correct strength of steroid to use.
Written by familydoctor.org editorial staff