By Dephanie Yeung

Many Hong Kong people long for the snow in winter. However, they feel unhappy and extremely embarrassed when another sort of flake appears in all seasons — the dandruff on their shoulders.

Dr. Lo Cheuk of the Chinese Medical Center for Rehabilitation and Therapy said, "Roughly speaking, the cause of dandruff is twofold: namely, natural and disease-induced.

"Dandruff is in fact a metabolic process. It removes old skin cells as well as the dirt in the hair," Dr. Lo added.

Also, dandruff occurs when the skin of the scalp overreacts to certain chemicals, like those contained in some hair gels and sprays.

Dr. Lo pointed out that the more people scratch their scalps, the more dandruff will be produced.

Dr. Fung Chi Wing, a dermatologist, agreed with Dr. Lo, adding that dandruff is closely related to a kind of yeast called Pityrosporum ovale.

He said, "There are large numbers of Pityrosporum ovale embedded in the hair of people with serious dandruff."

In the market, the most common ingredients of anti-dandruff shampoos are zinc pyrithione and coal tar.

According to the September 1994 issue of Choice magazine, zinc pyrithione and coal tar can suppress the growth of the Pityrosporum ovale.

Said Dr. Fung, "However, they can only restrain Pityrosporum ovale for a while. Later, the number of ovale will increase again and cause a faster growth of dandruff."

Excessive dandruff can be annoying. It is also a symptom of light seborrheic dermatitis, a pathological disease.

"When dandruff is caused by pathological diseases, it is a really serious problem," said Dr. Lo.

In such cases, one should consult a doctor to cure the underlying disease. Then dandruff will generally cease.

In winter, people usually have more dandruff.

Said Dr. Fung: "The dry wind in winter removes moisture from your skin and your scalp, and so the dandruff forms.

"Furthermore, the peak time for seborrheic dermatitis is in autumn and winter. This is why people usually have more dandruff in winter."

In addition, psychological factors have a bearing on the amount of dandruff an individual has.

"The more stress you are under, the more likely that you will have more dandruff," Dr. Fung said.

Dandruff can never be eliminated. However, it can be minimized.

"If it is due to stress, I will ask (patients) to relax," said Dr. Fung. "If pathological diseases are the cause, the cures for these will be applied. After that, dandruff will be less serious."

Various methods have been used to get rid of dandruff, such as using anti-dandruff shampoos, taking pills or applying ointments.

Said Dr. Lo: "Anti-dandruff shampoos may stop dandruff for awhile, but they sometimes contain chemicals harmful to the scalp."

Miss Lau Yin Hing, chief research officer at the Consumer Council said, "In our recent research we found that six brands of shampoos contain chemicals that may have adverse effects on some people."

Dr. Lo said, "Since there is not even one brand of shampoo that doesn't contain chemicals, I recommend the use of shampoos of milder form or a washing powder that contains camellia seeds."

Moreover, ordinary soap should not be used for washing hair, as hair is easily damaged.

Said Dr. Lo: "You should also wash your hair in a proper way. Before washing your hair, you should gently massage your scalp, and then wash and rinse it thoroughly."

Nevertheless, washing one's hair intensively to remove oil does not necessarily solve the problem, because there is no direct relationship between dandruff and oily scalps, doctors say.