Seborrheic dermatitis, also known as seborrhea, is a common non-contagious condition of skin areas rich in oil glands (the face, scalp, and upper trunk). Seborrheic dermatitis is marked by flaking (overproduction and sloughing of skin cells) and sometimes redness and itching of the skin. It can vary in severity from mild dandruff of the scalp to scaly red patches on the skin. The normal skin yeast, Pityrosporum ovale,
lives in oil-rich skin regions and plays a role in this disorder; the changes seen in the skin are due to the body's inflammatory response to the yeast found on the skin. Seborrheic dermatitis seems to worsen with stress, winter, and infrequent shampooing. Although there is no "cure" for seborrheic dermatitis, control is usually possible with medicated shampoos and topical steroid solutions, if inflammation is prominent.
Who's At Risk
Dandruff occurs in 15–20% of the population, and seborrheic dermatitis (with redness and flaking) occurs in 3–5%. The problem affects all races and may be a bit worse in men. It typically starts after puberty (although babies have a version called cradle cap). Seborrheic dermatitis peaks around the age of 40 and then may improve. Severe seborrheic dermatitis is seen frequently in people with Parkinson disease, central nervous system problems, and HIV infection.
Signs and Symptoms
- The scalp is itchy and sheds white, oily skin flakes.
- One or more of the following areas has patches of red, scaly skin: the scalp, hairline, forehead, eyebrows, eyelids, creases of the nose and ears, ear canals, beard area, breastbone, midback, groin, or armpits.
- In darker skin, some of the affected areas may look lighter in color.
Most cases of seborrheic dermatitis are easy to control with non-prescription home measures. These include:
- Frequent (daily) shampooing or a longer lather time with shampoo.
- Use of shampoos containing ketoconazole, selenium sulfide, 2% pyrithione zinc, salicylic acid, or tar-based shampoos.
- A little (not too much!) sun – this seems to suppress the growth of Pityrosporum.
- Managing any eyelid changes (blepharitis) by gentle cleaning of the skin around the eyelashes (eyelid margins) with a Q-Tip® and baby shampoo.
If a regular daily shampoo fails, consider an over-the-counter dandruff shampoo. There are several types and one may work better than another. Consider occasionally rotating shampoos, given that the efficacy of certain products can change with time.
If the scalp is covered with widespread, dense scale, the scale may first be removed by applying warm mineral oil or olive oil to the scalp and washing several hours later with a detergent, such as a dishwashing liquid or a tar shampoo.
Some over-the-counter creams will help if the medicated shampoo is not working well enough. These can be added to the shampoo used until improvement is noted and then can be discontinued, to be used again temporarily when needed. These include:
- Creams that reduce the Pityrosporum yeast (clotrimazole, miconazole, terbinafine).
- Hydrocortisone cream, which may work rapidly but may be less helpful if used for a long time.
When to Seek Medical Care
Seek medical help if there is no response to self-care measures.
Treatments Your Physician May Prescribe
- Corticosteroid creams or solutions
- Sulfur or sulfacetamide products applied topically
- Ketoconazole shampoo or cream
- Tacrolimus or pimecrolimus cream
- Topical lithium succinate ointment
Bolognia, Jean L., ed. Dermatology
, pp.215-218. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine
ed, pp.1198, 1200, 1374. New York: McGraw-Hill, 2003.