Friendly Print preview

... see also Psoriasis foundation sheets

Psoriasis

What is psoriasis?

It is a chronic skin disorder in which red or deep pink raised patches, covered by white scales, appear on the skin. It usually causes no discomfort but it can get slightly itchy, especially on the scalp or around the anus. The main problem is the unsightly appearance of the rash, but fortunately it is usually covered by clothing. You may have a single small patch or several large ones. The cause of psoriasis is unknown and it shows a tendency to run in families.

What part of the body is usually affected?

Psoriasis commonly affects the elbows, knees and scalp, although patches can surface anywhere on the body, including under the nails of the fingers and toes. It occurs less commonly in the armpits, under the breasts, on the genitals and around the anus.

Is psoriasis common?

Yes; it affects about 1 in 40 people. It appears most often between the ages of 10 and 30, and most cases are mild.

How does it happen?

The skin in the patches of psoriasis is growing much faster than normal skin. As your skin is worn away, it is replaced by cells produced beneath the surface. In psoriasis the normal rate of cell production is speeded up, and this does not allow the cells to manufacture a substance called keratin that gives skin its hard surface. The result is unsightly flaking of the skin.

Is it serious?

No; it does not affect general health. Some people (about 5% of those with psoriasis) can develop a painful arthritis in the joints.

How is psoriasis diagnosed?

A doctor can make a diagnosis on the appearance of the rash without the need for tests. If there is any doubt, a piece of skin can be removed for examination (a biopsy).

What are other important facts about psoriasis?

• It is worse in winter, due to the relative lack of sunlight.
• An outbreak is often triggered by a period of mental stress.
• Yellow blisters can occur in patches on the soles and palms.
• It is most unlikely to appear on the face.
• It should not prevent you from enjoying a normal life.
• It can temporarily disappear, especially during summer.
• It tends to flare up around puberty and the menopause in women.

What is the treatment?

• There are many treatments, depending on the severity of the condition and the nature of your skin. It is best to keep the treatment as simple as possible. It is worth noting that no special diet has proved successful as a treatment for psoriasis.
• For many people, careful sunbathing or using an ultraviolet lamp helps clear up psoriasis. However, if you have sensitive skin you must take care not to become sunburnt, because this can make the condition worse. The use of coal tar is a time-honoured treatment for psoriasis. Some patented preparations are messy, but patients should persevere with this effective and safe treatment.
• Your doctor will be able to advise you about the best drugs to treat your condition. A cautious approach is advised.

Note

• Psoriasis is not an infection and is not contagious.
• No one has a cure for psoriasis-beware of quack 'cures'.
• Avoid sunburn.

Copyright 1995: John Murtagh, Professor of General Practice
Monash University, Melbourne, Australia