Myths and facts about psoriasis

MYTH: Psoriasis is contagious.
FACT: It is not contagious.

One of the many ways the immune system protects the body against harmful substances is through inflammation, which is a process in which the body increases its blood flow to pump immune cells to a threatened part of the body to fight a pathogen.

In people with psoriasis, however, the immune system is inappropriately activated so that immune cells move to the skin and send out chemical messengers that speed up the growth of skin cells, causing inflammation. The autoimmune disease results in red inflamed patches of skin covered with silvery scales that flake off easily.

The causes of psoriasis have been blamed on genes and the environment.

About a third of patients have a parent or sibling with the condition.

Factors such as throat infections, the flu and especially physical and emotional stress, also play a role in triggering or aggravating the condition.

It affects men and women in equal numbers and may start at any age, though it usually starts more frequently between the ages of 15 and 30.

In eight out of 10 cases, psoriasis begins as a persistent dandruff in the scalp before spreading elsewhere, usually to the elbow, knees or back.

Itching is often experienced in hot humid climates.

About 15 per cent of patients may also develop arthritis. One in five patients have the severe form, when the red patches cover more than 10per cent of the body.

MYTH: Psoriasis is untreatable.
FACT: There is no cure but it can be controlled. There will be periods of remission alternating with periods of active skin disease. More effective types of treatment are now available.

Those with mild psoriasis generally manage their condition with moisturisers and topical creams, ointments or scalp solutions.

Those with more severe psoriasis may need phototherapy with ultraviolent light (two to three times a week) and oral medication which includes anti-inflammatory medicine such as cyclosporin and methotrexate, and a vitamin A derivative such as acitretin.

Unfortunately, oral medication can cause side effects such as bone marrow damage, liver and kidney damage and requires regular blood tests to detect these effects.

However, the latest treatment over the last five to 10 years - injections of biologic agents - come with fewer of such side effects. They work by blocking some of the immune mediators or substances that trigger inflammation of the skin in psoriasis.

But these injections are prohibitively expensive. Some patients require an injection every few weeks while others require an injection every few months. The average cost of the injection comes up to more than $1,000 a month.

Although long-term studies need to be done, it remains a promising treatment for those with severe psoriasis for whom phototherapy and oral medication have failed to work or those who may be at risk of suffering the side effects of oral medication.

Source: Dr Colin Theng, senior consultant at the National Skin Centre and head of the Psoriasis Association of Singapore

For more information, visit the Psoriasis Association of Singapore website at Psoriasis.org.sg.