Causes of Psoriasis
No-one knows exactly what causes psoriasis. However, it is thought that there are a number of factors that contribute to the development of psoriasis.
Your immune system plays a part in psoriasis, which is an ‘auto-immune’ disease. Click here to find out more about the immune system. In areas of the body affected by psoriasis there is a rapid increase in the speed at which skin cells are replaced. Skin usually takes around 28 days to renew and replace itself but, in areas affected by psoriasis, this process speeds up to between 3 to 4 days. The old skin cells do not have time to shed in the normal way and the new skin cells do not mature properly and create the thick patches of psoriasis.
The red appearance of psoriasis plaques can also be because of an increase in the number of blood vessels to the skin and can sometimes bleed.
There is also thought to be a genetic link with about 30% of people with plaque psoriasis having a close relative who has the skin condition.
Other factors that can trigger psoriasis flares include stress, alcohol, smoking and some medicines (such as lithium and beta-blockers.)
Awareness is increasing that psoriasis is more than a skin condition and can be associated with other health conditions including psoriatic arthritis, diabetes type 2, obesity and depression.