Dandruff (Seborrhea)

Dandruff, or scalp seborrhea, is often caused by a fungus but also can have autoimmune or other origins.

Those unpleasant white flakes on the collar of your dark shirt or blouse are dandruff. Dandruff is a sign that the skin of the scalp is peeling off (exfoliating). It is perfectly normal for the skin to exfoliate. The problem arises when the amount of dandruff becomes an eyesore.

There are basically two reasons for this:

• too much production, or
• not effective removal.

In the too much production category are inflammatory diseases of the scalp. In the ineffective removal category is inadequate scalp hygienic efforts.

The cause of seborrhea is unknown, although a yeast that often lives on the skin, Malassezia furfur, may play a role.

Some people who have weakened immune systems, such as those on chemotherapy or those with HIV disease or certain neurological disorders, may have very severe seborrhea. It is important to emphasize, however, that seborrhea is a very common condition, affecting perhaps 5% of the population (with men predominating). The vast majority of those who have it are completely healthy and have no internal or immune problems.

There are a variety of other inflammatory diseases that can produce excessive scaling and therefore dandruff, including psoriasis, fungal infection of the scalp skin (tinea capitis), and allergic contact dermatitis.

Seborrhea produces plaques of itchy red skin with scaling.

Dandruff itself produces no symptoms. However, the most common cause of dandruff, seborrheic dermatitis (seborrhea), is an itchy red rash that tends to occur on the scalp, ears, face, mid-chest, and mid-back.

The most common secondary manifestation of seborrhea of the scalp is dandruff. Seborrhea produces plaques of itchy red skin with scaling. It is the accumulated scale that we call dandruff. Reddish, scaly plaques may also appear in the eyebrows, on the forehead, in the ear canal, and on the folds of skin that extend from the nostril to the commissure of the lips. Although skin affected by seborrhea may feel and look dry, this is not the case; moisturizers are of little help in its control.

Scalp seborrhea may slow hair growth but does not cause permanent hair loss. Often, scalp seborrhea doesn't even itch significantly. Seborrhea can appear during infancy, starting shortly after birth and lasting several months. It may affect the scalp ("cradle cap") or produce scaly plaques on the body. Seborrhea may occur at any age.

Primary care providers and nurse practitioners can diagnose and treat most cases of dandruff. Dermatologists are experts in skin diseases.

After a thorough scalp examination, the cause of most cases of dandruff is usually apparent. Occasionally, physicians may find it necessary to perform a scalp biopsy where a small amount of scalp skin is removed under local anesthesia and submitted for examination under a microscope.

Treatment of seborrhea (dandruff) is directed at fighting skin inflammation. This is done either directly, by using cortisone-based creams and lotions (which reduce inflammation), or by using topical anti-yeast lotions and shampoos. Treatment should be directed at the cause of dandruff.

A primary care physician or dermatologist can recommend prescription-strength shampoos or antifungal and corticosteroid creams that are stronger than those available over the counter, yet are not too strong to use on the face.

There also are corticosteroid-based liquids, gels, and foams that you can apply to the scalp that won't leave the hair limp and matted. Non-steroid preparations like tacrolimus (Protopic) or pimecrolimus (Elidel) may also help.

Tar shampoos can help control dandruff on the scalp.

Shampoos

Here are some ingredients in medicated shampoos that can help control scalp dandruff. All are available over the counter. One can use any of these either all of the time or just once or twice a week, depending on how severe the symptoms are. If the problem quiets down or disappears, use non-medicated shampoos. If one kind of shampoo works for a while and "runs out of gas," switch to another. For resistant cases, alternate two different type

Many people, especially the elderly, believe that it may be harmful to shampoo frequently. Some avoid washing their scalp for more than a week. However, it is very unlikely that daily shampoos will produce any untoward effects other than removing dandruff.

• Tar (T/Gel)
• Salicylic acid (T/Sal)
• Zinc pyrithione (like Head & Shoulders)
• Selenium sulfide (Selsun Blue)
• Ketoconazole (Nizoral)

Topical steroids

Two additional types of medication that help seborrhea are cortisone creams and antifungal creams.

• Corticosteroid creams and lotions reduce inflammation. These can be purchased over the counter in either 0.5% or 1% concentrations. They are safe to use on the face and will often help in just a couple of days when applied twice daily. These products also are available as scalp lotions that are applied once a day, preferably on damp hair after shampooing. One can use scalp corticosteroid creams together with medicated shampoos.
• Antifungal creams are often effective, apparently because they reduce the number of yeast organisms living on the skin. Over-the-counter creams include 1% clotrimazole cream and miconazole cream 2%. Antifungal creams also are applied once or twice a day.

As with shampoos, creams should be applied until seborrhea subsides. When seborrhea comes back (and it will, sooner or later), the creams should be used again.

• Moisturizing: Moisturizing lotions don't do much more than smooth out scales and make plaques look redder.
• Switching brands of shampoo: Shampoo doesn't cause dandruff. However, medicated shampoos (see below) can help.
• Changing hair-care routines: There is no "right" shampoo or conditioner. What is more important is the frequency with which these agents are used. As a rule, the more frequently you shampoo, the better the result. Seborrhea and dandruff are not caused by excessive shampooing "drying out the scalp." Hair dyes and conditioners do not cause or aggravate dandruff.
• Switching antiperspirants: When underarms are red from seborrhea, almost anything will make them redder, including antiperspirants, even though they are only aggravating the condition and not causing it.

Scalp dandruff

Most simple uncomplicated dandruff responds to frequent shampooing. As with all seborrhea (dandruff) treatments, medicated shampoos, and cortisone creams calm down the skin or scalp sensitivity, but they can't permanently stop dandruff from coming back. Most people, however, only have to treat their condition from time to time when it becomes itchy or noticeable.

Eyelash dandruff

Dandruff (seborrhea) of the eyelashes can be both annoying and hard to treat. Eye doctors like to recommend scrubbing the lashes with baby shampoo on a cotton swab. Corticosteroid-based lotions should be used close to the eye only under medical supervision since continuous exposure of the eye to these products can lead to serious eye problems.

Yes. Frequent shampooing will prevent most cases of dandruff.