Psoriasis – NHS Choices

Psoriasis is a skin condition that causes red, flaky, crusty patches of skin covered with silvery scales.

These patches normally appear on your elbows, knees, scalp and lower back, but can appear anywhere on your body.Most people are only affected with small patches. In some cases, the patches can be itchy or sore.

Psoriasis affects around 2% of people in the UK. It can start at any age, but most often develops in adults under 35 years old. The condition affects men and women equally.

The severity of psoriasis varies greatly from person to person. For some people it's just a minor irritation, but for others it can havea major impact on their quality of life.

Psoriasis is a long-lasting (chronic) disease that usually involves periods when you have no symptoms ormild symptoms, followed by periods when symptoms are more severe.

Read more about the symptoms of psoriasis.

People with psoriasis have anincreased production of skin cells.

Skin cells are normallymade and replaced every three to four weeks, but in psoriasis this process only lasts about three to seven days. The resulting build-up of skin cells is what creates the patches associated with psoriasis.

Although the process isn't fully understood, it's thoughtto be related to a problem with the immune system. The immune systemis your body's defence against disease and infection, but for people with psoriasis, it attacks healthy skin cells by mistake.

Psoriasis can run in families,although the exact role that genetics plays in causing psoriasis is unclear.

See original here:
Psoriasis - NHS Choices