Psoriasis is a common, chronic (lifelong), non-infectious, scaly rash that affects people of all ages (about 2% of the population). It occurs equally in men and women and can affect any age. Psoriasis can affect the skin, scalp and nails, and varies in its severity.
What Causes Psoriasis?
The skin is made up of several layers, the outer layer of skin contains cells that are formed at the bottom layer of skin and move upwards – this takes 3 to 4 weeks, but in psoriasis the rate of skin cell turnover is much higher – as little as 3 days – which results in thickening of the skin and the scaly rash of psoriasis. Psoriasis may run in families and may get worse following certain infections and at times of stress.
For most people that develop psoriasis that comes and goes, there is no obvious cause that can be detected.
How is Psoriasis Diagnosed?
Psoriasis is clinically diagnosed by a skin specialist. Blood tests are not needed although occasionally a skin biopsy may be helpful.
How is Psoriasis Treated?
As psoriasis varies greatly in its severity then treatments can be diverse. There is no cure but it can be improved using soap free cleansers, moisturizing creams and prescribed creams containing tar, steroid or other agents. Scalp psoriasis can be treated with steroid, coal tar or calcipotriol containing scalp preparations/shampoos. Many people improve with hospital ultra violet light treatment which occurs 2 or 3 times a week over several weeks as an outpatient. More severe psoriasis can be treated with tablets such as methotrexate, ciclosporin or acitretin, or injections (biologic therapy). Most people with psoriasis will need a combination of treatments according to how their psoriasis changes with time.