Seborrheic dermatitis: Overview
What is seborrheic dermatitis?
This is a very common skin disease that causes a rash. When this rash appears, it often looks like the one shown on this page. The skin tends to have a:
Swollen and greasy appearance
White or yellowish crusty scale on the surface
One or more of these rashes can appear on the body. Sometimes, the affected skin itches.
Despite its appearance, this skin disease is not caused by poor hygiene.
Cradle cap: A type of seborrheic dermatitis
Many infants get cradle cap. This is a type of seborrheic dermatitis that develops in babies. Scaly, greasy patches form on the baby’s scalp. The patches can become thick and crusty, but cradle cap is harmless. Cradle cap usually goes away on its own within a few months.
Babies also get seborrheic dermatitis in their diaper area and elsewhere. In the diaper area, the red rash often is mistaken for diaper rash. A few babies get seborrheic dermatitis that covers much of the body with red, scaly patches.
No matter where the seborrheic dermatitis forms, it tends to permanently disappear between 6 months and 1 year of age.
Seborrheic dermatitis is long-lasting in adults
When an adult gets seborrheic dermatitis, the condition can come and go for the rest of the person’s life. Flare-ups are common when the weather turns cold and dry. Stress also can trigger a flare-up. The good news is that treatment can reduce flare-ups and bring relief.
Images used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.
Habif TP, Campbell JL, et al. “Seborrheic dermatitis.” In: Dermatology DDxDeck. China, Mosby Elsevier:
2006, p. 40.
Plewig G Jansen T. “Seborrheic Dermatitis.” In: Wolff K, Goldsmith LA, Katz SI, et al. editors. Fitzpatrick’s Dermatology in General Medicine, 7th ed. United States of America, McGraw Hill Medical; 2008. p.219-25.