What is psoriasis?
Psoriasis is a common chronic inflammatory skin condition that involves red elevated patches and flaking silvery scales. It can take on several different forms and appearances, and symptoms can range from mild to severe. 

Signs and symptoms
The lesions can be painful and/or itchy and vary in size. Since plaques consist of dry, flaky inflamed skin, it may also crack and bleed. While lesions can appear anywhere on the body, the most common sites include elbows, knees, scalp, chest and lower back. The plaques tend to appear in the same place on both sides of the body.

Who is at risk?
Psoriasis can develop at any age, although it is typically seen in adults. One form of psoriasis called guttate psoriasis tends to occur in childhood and early adulthood. Psoriasis occurs equally among men and women and across different races. Family history of psoriasis is a leading risk factor. In recent years, research has been discovering some of the genes involved in psoriasis.

What causes it?
While it is not known exactly what causes psoriasis to develop in certain individuals, experts believe that the condition may involve malfunctioning of the immune system and the consequent production of inflammation. White blood cells (T cells) in the immune system are triggered and this causes inflammation to occur, which then causes skin cells to rise to the surface and shed at an abnormally quick rate. Skin cells shed every 3 to 4 days in psoriasis whereas in normal healthy skin, the skin cells turnover cycle is typically 30 days.

Living with psoriasis
Despite being labelled as a skin disease, psoriasis has an impact on patients that extends beyond the cosmetic or physical aspects. According to a national patient survey, psoriasis and related conditions “impose a sever burden on the daily lives of Canadians with a history of moderate to severe psoriasis.” Over one third of respondents (176 of 500) viewed their skin condition as a significant problem in their daily life. The perception seemed to correlate with the extent of disease or how much of their body surface psoriasis affected.

Psoriatic lesions can be itchy, painful and bleed, making it difficult to sleep, dress or engage in various daily activities. If there is joint involvement, the pain can also make it challenging for the individual to function physically. In terms of physical and mental disability, psoriasis has been compared to having cancer, arthritis, hypertension, heart disease, diabetes, and depression. The quality of life is the major concern. The aim of treatment is ultimately to reach an appropriate quality of life.

Quick facts about psoriasis

• Psoriasis affects 1 million Canadians and 80 million people worldwide.
• The most common form is plaque psoriasis, which affects approximately 90% of patients.
• Psoriasis often causes as much disability as cancer, diabetes and other major medical diseases.
• Up to 30% of patients with psoriasis have or will have arthritis and 5–10% may have some functional disability from arthritis of various joints.