How do you get plaque psoriasis?

While scientists do not know what exactly causes psoriasis, we do know that the immune system and genetics play major roles in its development. Usually, something triggers psoriasis to flare. The skin cells in people with psoriasis grow at an abnormally fast rate, which causes the buildup of psoriasis lesions.

Men and women develop psoriasis at equal rates. Psoriasis also occurs in all racial groups, but at varying rates. About 1.9 percent of African-Americans have psoriasis, compared to 3.6 percent of Caucasians.

Psoriasis often develops between the ages of 15 and 35, but it can develop at any age. About 10 to 15 percent of those with psoriasis get it before age 10. Some infants have psoriasis, although this is considered rare.

Psoriasis is not contagious. It is not something you can "catch" or that others can catch from you. Psoriasis lesions are not infectious.

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How is psoriasis diagnosed?

There are no special blood tests or tools to diagnose psoriasis. A dermatologist (doctor who specializes in skin diseases) or other health care provider usually examines the affected skin and determines if it is psoriasis.

Your doctor may take a piece of the affected skin (a biopsy) and examine it under the microscope. When biopsied, psoriasis skin looks thicker and inflamed when compared to skin with eczema.