What is psoriasis?
Psoriasis is a chronic skin disorder characterised by well defined silvery scaly patches. It can affect any part of the body but is particularly common on the elbows, knees, scalp, back and buttocks.

How common is psoriasis?
Psoriasis affects between 2 - 4% of the population. It affects all races and sexes but appears to be less common in Blacks.

What causes psoriasis?
Psoriasis is caused by an acceleration in the epidermal cell division rate to 20 times the normal, leading to the accumulation of skin scales. Exactly why this happens is unknown but inheritence and environmental factors both play a role. A family history of psoriasis can be found in a third of patients. Some of the environmental factors that are known to precipitate psoriasis in a later section but there are probably others that have not been identified yet.

When does psoriasis appear?
Psoriasis can occur at any age but is most common between 10 - 40 years.

What other problems does psoriasis cause?
Arthritis may develop in 5 - 10% of patients. Nail changes in the form of pitting, onycholysis (lifting of the nail plate) and yellowish-brown "oil-spots".

What is the treatment for psoriasis?
There are several treatments available including external medicines such as steroids, tar, dithranol or anthranol (a derivative of tar) and tazarotene, internal medicines such as acitretin (a vitamin A derivative), methotrexate (an anti-cancer drug) and cyclosporin (a drug used to prevent the rejection of transplanted organs) or one of the newer biologic agents and phototherapy (light therapy) in the form of ultraviolet B or PUVA (psoralen plus ultraviolet A). Generally, internal medicines are reserved for the more severe or unresponsive cases because of possible side effects. Sometimes the treatments are combined.

Can psoriasis be cured?
The answer here is no but it can be treated and controlled enough for the person to lead a normal life. Psoriasis is rather unpredictable. In some patients it may stay away for years or the patches may remain unchanged for many years. In others, it recurs very frequently.

What may make psoriasis worse?
Several factors may cause psoriasis to flare:

• Streptococcal sore throat
• Physical trauma such as sunburns, scratches, cuts or injury to the skin can cause psoriasis to appear at the site
• Stress
• Certain drugs such as beta blockers, lithium, anti-malarials.

Is psoriasis caused by diet?
No, diet has no effect on psoriasis.

 

Is psoriasis contagious?
No it is not.

 

Does psoriasis cause hairloss?
Usually not but very occasionally there may be minor hairloss over the area of scalp affected by psoriasis but this is temporary.

 

Does sunlight help psoriasis?
Yes, sunlight is helpful and is used by doctors. However, too much sunlight can cause burns (which may make psoriasis worse) and photoageing, so don't overdo it.

 

Go to psoriasis at Skin A to Z