Seborrhoea is a common form of skin eczema that occurs in parts of the body with high oil (sebum) production. Body areas that are commonly affected include the scalp, ears, face, chest, and folds of skin, such as the underarms or the skin below breasts or overhanging abdominal folds. The cause of seborrhoea is unknown, although a yeast that often lives on the skin, Malassezia furfur, may play a role.
One common manifestation of seborrhoea that affects the scalp is dandruff. Scalp seborrhoea can also present as thick, flaky, localised patches of scale. On the face, seborrhoea produces reddish-brown, dry-looking, or thick, greasy scales on the eyebrows, sides of the nose, and behind the ears. Reddish, scaly patches may also appear in the folds of skin mentioned above.

Although skin affected by seborrhoea may feel “dry,” moisturising only makes them redder. Scalp seborrhoea and dandruff do not cause permanent hair loss. Often, scalp seborrhoea doesn’t even itch significantly. Seborrhoea can appear during infancy, starting shortly after birth and lasting several months. It may affect the scalp (cradle cap), or produce scaly patches on the body. Adults of all ages may develop seborrhoea, too, especially on the scalp and face. 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 seborrhoea. It is important to emphasise, however, that seborrhoea is a very common condition.

What treatments are available for seborrhoea?
Treatment of dandruff is directed at fighting the skin inflammation. This is done either directly, by using cortisone-based creams and lotions (which reduce inflammation), or by reducing the yeast that builds up on scaly areas and adds to the problem.

What doesn’t help seborrhoea?
• Moisturising: Moisturising lotions don’t do much more than smooth out scales and make patches look redder.
• Switching brands of shampoo: Shampoo doesn’t cause dandruff. However, medicated shampoos can help.
• Changing hair-care routines: There is no “right” shampoo or conditioner, nor is there a “correct” number of times to shampoo per week; seborrhoea 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 seborrhoea, almost anything will make them redder, including antiperspirants, even though they are only aggravating the seborrhoea and not causing it.

What over-the-counter products can help?
• Medicated shampoos: You can these either all of the time, or just once or twice a week, depending on how severe your symptoms are. If the problem quiets down or disappears, stop and use nonmedicated shampoos. If one kind of shampoo works for a while and “runs out of gas,” switch to another. For resistant cases, you can even alternate two different types.

• Creams: Two additional types of medication that help seborrhoea are cortisone creams and antifungal creams. Cortisone creams reduce inflammation. 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. You can use scalp cortisone creams together with medicated shampoos.

• Antifungal creams are often effective, apparently because they reduce the number of yeast organisms living on the skin. As with shampoos, creams should be applied until the seborrhoea subsides. When the seborrhoea comes back (and it will, sooner or later), the creams should be used again.

What can the doctor prescribe?
Your physician or dermatologist can recommend prescription-strength shampoos or antifungal and cortisone creams that are stronger than those available over the counter, yet are not too strong to use on the face. There also are cortisone-based liquids, gels, and foams that you can apply to the scalp that won't leave your hair limp and matted. As with all seborrhoea treatments, prescription-strength shampoos and cortisone creams calm down your skin or scalp sensitivity, but they can't stop the seborrhoea from coming back. Most people, however, only have to treat their condition from time to time when it becomes itchy or noticeable.