Psoriasis can flare up on any part of the skin – when it appears on the scalp, it’s known as scalp psoriasis. But wherever it appears, the cause is the same.
It happens when faulty signals in the immune system tell the body to fight an infection (even when one is not present).
This releases inflammatory chemicals as part of the immune response, causing skin cells to work overtime, reproducing quicker than usual.
Typically, skin cells in a non-sufferer will renew around every 21-28 days – it’s a natural process and is invisible to the naked eye.
But if you suffer from psoriasis, they may reproduce up to 10 times quicker, causing plaques of excess skin cells to appear on the surface of the skin.
What causes a flare-up?
While the immune response which causes psoriasis is well known, the triggers which cause the immune system to respond in such a way in sufferers are less well known.
While there is no cure for psoriasis, some people will see flare-ups and in some cases the condition can go into remission for long period before reappearing again.
Factors like stress, injuries to the skin or hormonal changes can aggravate the condition and have been shown to cause flare-ups in psoriasis sufferers.