Seborrhoeic Dermatitis

Seborrhoeic dermatitis is a skin disorder affecting the scalp, face and trunk causing scaly, flaky, itchy, red skin. It particularly affects the sebum-gland rich areas of skin.

Etiology

The cause of seborrheic dermatitis remains unknown, although many factors have been implicated. The ubiquitous yeast, Malassezia furfur (formerly known as Pityrosporum ovale), is involved, as well as genetic, environmental, hormonal, and immune-system factors. It has been suggested that seborrheic dermatitis is an inflammatory response to this organism, but this has yet to be proven. Those afflicted with seborrhoeic dermatitis have an unfavorable epidermic response to the infection, with the skin becoming inflamed and flaking.

Treatments

Soaps and detergents such as Sodium Laureth Sulfate may precipitate a flare-up, as they strip moisture from the top layers of the skin, and the drying property of these can cause flare-ups and may worsen the condition. Accordingly a suitable alternative should be used instead.

Among dermatologist recommended treatments are shampoos containing coal tar, ketoconazole, selenium sulfide, or zinc pyrithione. For severe disease, keratolytics such as salicylic acid or coal tar preparations may be used to remove dense scale. Topical terbinafine solution (1%) has also been shown to be effective in the treatment of scalp seborrhea, as may lotions containing alpha hydroxy acids or corticosteroids.

Chronic treatment with topical corticosteroids may lead to permanent skin changes, such as atrophy and telangiectasia.

UV-A and UV-B light inhibit the growth of M. furfur, although caution should be taken to avoid sun damage.