Psoriasis is a long-term skin condition that can also affect joints. Although the cause of psoriasis is unknown, it is thought that psoriasis occurs in people who have a genetic tendency for their immune system in their skin to react to certain triggers. Crohn's disease occurs more commonly in patients with psoriasis. People with severe psoriasis have an increased risk of developing diabetes and cardiovascular disease.
Psoriasis causes different symptoms in different people.
The most common symptoms are dry, raised, red patches of skin (plaques) covered with silvery scales. The patches usually appear on the knees, elbow and scalp, but they can appear anywhere on the body.
Psoriasis can also cause dents and discolouration of the nails.
Some people get small, drop-shaped sores on the chest, arms, legs or scalp. Some people get swollen, painful joints.
The symptoms of some rare types of psoriasis include pus-filled blisters or a red, peeling rash that itches or burns intensely.
How is psoriasis diagnosed?
If you think you have psoriasis, see your doctor. Your doctor will probably ask you some questions and examine your affected skin. Your doctor may refer you to a dermatologist, or a rheumatologist if your joints are affected.
How is psoriasis treated?
There is no cure for psoriasis but there are many treatments that can help to keep it under control.
Mild psoriasis is usually treated with products applied to the skin. These include:
- tar preparations
- corticosteroid creams or ointments
- vitamin D preparations
You may also receive ultraviolet light therapy. This can slow down the production of skin cells.
If your psoriasis needs stronger treatment you may be prescribed oral medicines (tablets or pills) or injected medicines.
You can help manage your psoriasis by:
- taking your prescribed treatment regularly to help prevent flare-ups
- reducing stress
- having a healthy lifestyle — including cutting down on alcohol, not smoking, and eating a healthy diet
Your guide to psoriasis - video
Last reviewed: March 2019