Psoriasis Overview, Causes of Psoriasis

Psoriasis Overview

Psoriasis is a chronic skin disorder that affects about 2% of the population. It is characterized by red, elevated plaques that are often overlaid with thick, silvery white scales. The most commonly affected areas are the elbows, knees, scalp, lower back, and genitalia. Some people have psoriasis on their hands and feet. A condition called inverse psoriasis manifests plaques in folded areas, such as in the armpits and groin.

Questions to Ask Your Doctor about Psoriasis
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While psoriasis can develop at any age, it seems to have two peaks of onset incidence: in the third and sixth decades of life. Psoriasis can be physically and emotionally disabling. This disease is often inherited and carries the potential for causing arthritis (psoriatic arthritis).

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People with severe psoriasis have a shorter life expectancy, says a study published recently in the Archives of Dermatology. The study tracked patients in the UK for 15 years and defined "severe" as needing systemic treatments; however the study was done before medications known as biologics were available.

More research is required to determine if severe psoriasis is a direct cause of reduced life span or if factors associated with the disease—such as smoking, drinking, obesity and social isolation—are the cause.

Although the likelihood for familial transmission may not seem significant, there is a definite genetic predisposition for psoriasis. When one parent is affected, there is roughly a 10% risk of a child acquiring psoriasis. The risk rises to almost 50% when both parents have psoriasis. One study analyzing psoriasis in twins found 65% of identical twin siblings had psoriasis when the other twin was affected. The exact mode of inheritance is complex and variable. The National Psoriasis Foundation reported that researchers have discovered evidence that psoriasis is an autoimmune disorder.

Most people with psoriasis report that no particular event or illness preceded or brought about their condition, but several well-known triggers include stress, strep infection, and some medications.

Smoking Increases Risk of Psoriasis

Researchers have found that smokers are at increased risk of developing psoriasis. The study appeared in the American Journal of Medicine and looked at 78,532 women over a 14-year period. The heaviest smokers were at the highest risk; quitting reduces the risk slowly, over a period of years.

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