Psoriasis is a disease whose main symptom is grey or silvery flaky patches on the skin which are red and inflamed underneath. It affects 2 percent of the population in the UK. Commonly affected areas include the scalp, elbows, knees, navel, palms, ears and groin. Psoriasis is autoimmune in origin, and is not contagious. Around a quarter of people with psoriasis also suffer from psoriatic arthritis, which is similar to rheumatoid arthritis in its effects. It may appear for the first time at any age, although it is more likely to appear between the ages of 11 and 45.

Psoriasis was first given that name in complete differentiation from other skin conditions by the Austrian dermatologist Ferdinand von Hebra in 1841, although there are what are believed to be descriptions of the disease in sources going back to ancient Roman and possibly even biblical times. Psoriasis is derived from the Greek word 'psora', which means itch.   

Psoriasis - the facts

What are the symptoms?

• Normally there is a constant shedding of dead cells. However, due to the acceleration of the replacement process, both dead and live cells accumulate on the skin surface.
•  Often this causes red, flaky, crusty patches covered with silvery scales, which are shed easily.
• It can occur on any part of the body although it is most commonly found on the elbows, knees, lower back and the scalp.
• It can also cause intense itching and burning.

Who is at risk?

• Psoriasis affects approximately 3% of people globally.
• It can start at any age, but most often develops between the ages of 11 and 45, often at puberty.
• The condition is not contagious and most people have only small patches of their body affected.
• There is a genetic link and it tends to run in families. About 30% of people with one first degree relative with psoriasis develop the condition.
• This genetic tendency appears to need to be triggered by infection; certain medicines, including ibuprofen and lithium; psychological factors, including stress; or skin trauma.
   

Fast Facts

• Psoriasis is a dry, scaly skin condition in which cells are produced too quickly
• Normally skin cells take about 21 to 28 days to replace themselves, in psoriasis they take around 2 to 6 days
• It affects approximately 3% of people globally
• It usually develops between the ages of 11 and 45
• It is not contagious
• Psoriasis is unpredictable
• Some people with the condition suffer from social exclusion and discrimination
   

There is no way of predicting who will develop psoriasis. 50-60% of people who first experience it do not know of anyone else in their family who has had it.