"When you have to apply ointment all over your body, it is impractical. It also has a smell and when you go to work, your colleagues will start asking questions," said Lai, who was 24 when he was diagnosed.

Now Lai, 41, and other Hong Kong residents suffering from psoriasis - a lifelong autoimmune disease that covers the skin in red, scaly plaques - have joined hands to press the government to help subsidize their high treatment costs.

Affecting up to two percent of the population in Asia, or 125 million people worldwide, this disfiguring disease can take a higher physical and mental toll on patients than cancer and heart disease, past surveys have found.

"During all that time, I experienced great stress and prejudice. In the subway, people around me will stare at me and they think I may infect them," said Lai, a data analyst. "I can tell from their eyes even if they don't say anything."

In psoriasis patients, skin cells grow too fast and rapidly pile up, forming red and inflamed scales or plaques on the skin. While cell reproduction in normal skin takes 28 days, that process in psoriasis patients takes only four days.

The exact cause of psoriasis remains unknown although experts believe it is linked to the immune system where a class of fighter cells attack the body's own healthy skin cells by mistake. They cite a combination of risk factors, including genetic predisposition and environmental factors.

Dermatologist Yeung Chi-keung said first-line treatments such as creams, exposure to ultraviolet light and oral drugs tend not to work for about 10 percent of patients, who will then require second-line drugs, which are injected.

These injectable drugs now cost an average of HK$10,000 (US$1,282) a month and getting on Hong Kong's general list will mean patients need only pay a nominal administrative fee of $10.

"In the last month, we (dermatologists in Hong Kong) proposed to the government to consider subsidizing these drugs," said Yeung, who is honorary clinical associate professor of dermatology at the University of Hong Kong's department of medicine.

A spokesman for the Hospital Authority, the body that oversees all public hospitals in Hong Kong, said it would have to make a detailed study before deciding if it will subsidize the treatment of such patients.

"The review process would take into account scientific evidence on safety, efficacy and cost-effectiveness as well as actual clinical experience in the use of drugs. Views of professionals and patient groups will also be considered," the spokesman added.

For the patients who wait and hope, the stress never goes away.

"When I go to the pool, other swimmers think it is contagious and that I will pollute the water, so they complain to the lifeguard to get rid of me," Lai said. "We hope the government will put these drugs on their general (subsidized) list."

(Reporting by Tan Ee Lyn, editing by Elaine Lies)

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