[Skin Sense] What is seborrheic dermatitis?

A male patient in his 40s will come to visit a dermatology clinic for itchy, scaly, reddish problems on his face and including flaky dandruff on his scalp.

Seborrheic dermatitis is one of the most common skin disorders. It is mainly a cosmetic problem and usually can be easily treated.

This condition is an inflammation in areas having the greatest number of sebaceous or oil glands of the skin, the scalp, sides of the nose, eyelids, and the skin behind the ears and middle of the chest are most commonly affected. Other areas, such as the navel and skin folds under the arms, breasts, groin and buttocks, may also be involved. The affected skin is red and is covered by yellowish, greasy-appearing scales. Itching may or may not occur. When it does, it is usually mild.

Dandruff is characterized by too much scaling on the scalp. There is no skin inflammation. Seborrhea describes excessive oiliness of the skin, especially of the scalp and face. There is no redness and scaling. Patients with seborrhea may later develop seborrheic dermatitis.

This condition can occur at any age, but is most common in three distinct age groups infancy, when it's called "cradle cap," middle age, and old age. It's not known why it occurs in older people.

Cradle cap in infancy usually clears without treatment by age eight to 12 months. This may be due to the gradual disappearance of hormones passed from the mother to the child before birth. Gentle shampooing is helpful. In some children, this condition may develop only in the diaper area where it could be confused with other forms of diaper rash. When seborrheic dermatitis develops at other ages, it may appear, disappear and then reappear. Whether treated or not, this condition comes and goes.

While it may subside without treatment, it usually improves temporarily with treatment. In any case, this condition tends to recur.

There is no way to prevent the development or recurrence of seborrheic dermatitis. If the rash is a cosmetic problem or if symptoms such as itching are significant, it should be treated. If the scalp is involved, frequent shampooing is usually recommended once the condition clears up.

This skin disorder is treatable but may recur periodically, requiring re-treatment. One of the more effective methods of treatment is low strength cortisone cream or hydrocortisone applied to the affected areas of skin. For patients who do not respond to this treatment, there are several other effective medications that a dermatologist can prescribe. The frequent use of nonprescription shampoos containing tar, zinc pyrithione, selenium sulfide, sulfur and/or salicylic acid may be recommended by a dermatologist. A dermatologist may recommend a prescription shampoo for the patient. In addition, some patients may need to use stronger cortisone preparations. They should be sure to follow their dermatologist's advice, since prolonged use of these medications should be avoided.

Recent evidence suggests that this skin disorder may be intensified or perpetuated by a yeast-like organism. This organism is normally found on non-diseased skin in low numbers. With the increased scaling and retention of oil in seborrheic dermatitis, this yeast grows to very high numbers and can aggravate the inflammation of the disease. Specific prescription creams and shampoos can be helpful in controlling the condition in some people.

For further information, call Lee Ji Ham Skin Clinic, Tel: 706-7600/ Fax: 704-7740.

Updated: 12/16/1999, by Chung Hae-shin

Korea Herald