Psoriasis – The Facts

    Psoriasis is a skin disease characterized by thick scales appearing on the skin. The affected skin becomes dry, scaly with whitish powder like appearance. Itching, though usually mild, is often experienced in our hot and humid climate.

    As part of our skin, nails also show changes like “pitting” of their surface in up to half of people with psoriasis. Joint pains and swelling are associated in more extensive psoriasis.

    How do you know if you have Psoriasis?

    It usually presents with red scaly patches on the scalp, body and limbs. The scaly patches on the scalp are usually thicker and more extensive than ordinary dandruff. Common sites of the body affected are the elbows, the knees and the back.

    Why does Psoriasis happen?

    The cause are largely unknown. Studies point to a genetic background, and a history of similar illness in the family is noted in up to 40% of patients. However complex interaction with environmental factors are necessary to trigger off the appearance of psoriasis. Once it starts, there will be periods of remission alternating with periods of active psoriasis.

    What can make it worse?

    Physical and emotional stress are well known to aggravate psoriasis. Throat infections or the flu may trigger off aggravation of the disease. Some drugs, e.g. steroid hormones and certain anti-hypertensives may provoke its appearance.

    What’s the natural history of Psoriasis?

    It usually starts in the 20’s but has been described at birth and in old age. Like diabetes and other chronic diseases, psoriasis has a delayed onset, and seldom remits permanently. However, unlike other chronic illnesses, it rarely shortens life expectancy. It has a tendency for recurrence.

    What treatments are available?

    Topical Creams, Ointments, Lotions, Shampoos & Scalp Solutions:
    Most people have mild disease and get considerable relief with local creams/ointments. These include coal tar, anthralins, steroids and vitamin D3 derivatives (e.g. calcipotriol) ointment/cream. For the face, hairline and groin areas, mild steroid creams are usually used.

    • For psoriasis on the scalp, tar shampoos and steroidal lotions/gels are commonly used to control it. Others include coal tar ointment & vitamin D3 derivatives (e.g. calcipotriol) scalp solution.
    • Photo therapy

    Patients often also respond to ultraviolet (UV) light treatment. Ultraviolet light, either UVB or UVA have been found to be effective in clearing psoriasis if used in gradually increasing doses over a period of one to several months.

    UVA is usually given with tablets called psoralens to enhance the effect of photo-therapy (PUVA). Because of certain side-effects, this treatment has largely been replaced by a new type of photo-therapy called Narrow-band Ultraviolet light therapy. Narrow band refers to UV light with wavelength 311nm. This is one of the safest therapies for psoriasis and is highly effective.

    Oral Drugs

    Your dermatologist may prescribe oral medications when it does not respond to topicals and photo-therapy. Examples of such drugs are methotrexate, cyclosporin, acitretin and sulphasalazine. Unfortunately, these drugs cause side-effects. Patients who are taking such drugs will require regular blood tests to detect side-effects e.g. liver damage, bone marrow damage, etc.

    How we can handle Psoriasis?


    • Accept the fact that you have psoriasis.
    • Use treatments regularly as directed.
    • Keep skin moist as this will help reduce itching and scaling.
    • Protect the skin against scratches and cuts as this may cause it to flare up at the site of injury.
    • Remember that the sun may help the psoriasis but be careful not to burn.


    • Don’t scratch the plaques as this may damage the skin and actually worsen psoriasis.
    • Don’t give up treatments too soon as it may take a few weeks for some of them to work.
    • Don’t indulge in self-pity and avoid people. Psoriasis is not evil. Learn to accept it as a part and parcel of life. Do not keep thinking about it.

    Fiction – Is Psoriasis contagious?


    Will I pass it on to my children?

    Not necessarily. Psoriasis is a hereditary disorder but only about 10% of people with psoriasis have a family member affected by psoriasis. The cause of psoriasis is multi-factorial and inherited genes do not always express disease without the appropriate environmental triggers.

    Is Psoriasis a rare skin disease?

    No, it is not an uncommon skin disease. It is estimated that 1 – 2% of the population in Singapore have psoriasis.

    Are there any foods to avoid, or supplements to help?

    No. But it is wise to consume a nutritious, balanced diet containing more green vegetables and less meats. Alcohol abuse is best avoided because of its associated malnutrition and liver disease.

    Is there a quick cure?

    No, but your doctor should be able to help you control it. Oral steroid treatment is best avoided because although it helps to clear psoriasis fast, it invariably results in a quick and severe rebound of psoriasis. But remember, psoriasis can be controlled with appropriate treatment.