Psoriasis occurs when the cells in the skin reproduce too rapidly; normally the life cycle of the skin lasts around 28 days but in people that suffer from psoriasis the cycle only takes between 2 and 6 days. As a consequence, patches of dry, flaky skin form on the surface of the skin. Psoriasis is a long-term condition, which can flare up at any time; it is not contagious so it cannot be passed on from an infected person to another person.
Causes of psoriasis
It is not known why the skin cells in some people reproduce at a more rapid rate but scientists believe it is associated with the antibodies produced by the immune system; in psoriasis sufferers, the T cells (a form of antibody) start attacking the healthy skin cells. Psoriasis often runs in families and is more common in those with conditions that affect the immune system. There are also certain triggers which may cause psoriasis to flare up; these include:
- Smoking
- Drinking
- Stress
- Medications (including anti-malaria tablets, anti-inflammatory medications and medication to treat high blood pressure)
- Cuts or scratches
Treatment for psoriasis
There is no cure for psoriasis but there are a number of treatments that can be used to ease the symptoms. Most mild cases of psoriasis are treated with topical medications (these include creams and lotions which are applied directly to the skin); topical treatments include corticosteroids, vitamin D analogues (these help to slow the reproduction of skin cells) and dithranol (this is highly effective but it may stain so it is usually carried out in hospital). Phototherapy may also be used to treat psoriasis; this method uses exposure to light beams to reduce the production of skin cells. Severe cases of psoriasis may be treated with a combination of oral and injected medications; usually these will be prescribed by a dermatologist.