Psoriasis is a common and chronic condition that usually causes patches of itchy, scaly and sometimes inflamed skin.

Although they can appear anywhere, these patches -- called plaques -- are most likely to crop up on your knees, elbows, hands, feet, scalp or back. In about 50% of cases, the fingernails and toenails are also affected.

The symptoms of psoriasis can vary a great deal depending on its severity, ranging from mildly annoying to truly debilitating.

While the itchiness and pain can be unpleasant to say the least, some of the worst effects of psoriasis can be emotional. People with severe psoriasis sometimes are so overwhelmed by their condition and self-conscious of their appearance that they feel isolated and depressed.

Researchers estimate that up to seven million people in the U.S. have psoriasis, about 1% to 2% of the population. Unfortunately, there isn't a cure for this condition, but there are a number of effective treatments that can help keep psoriasis under control. *Data from the National Psoriasis Foundation.

Psoriasis Statistics


About 2.2 percent of the U.S. population has psoriasis
More than 4.5 million adults in the United States have been diagnosed with psoriasis


Often appears between the ages of 15 and 25, but can develop at any age


Less than 3 percent of the body affected by psoriasis is considered to be a mild case, while 3 to 10 percent is considered moderate. More than 10 percent is considered severe. The palm of the hand, including fingertips, equals approximately 1 percent of the skin. However, the severity of psoriasis is also measured by how psoriasis affects a person's quality of life. Psoriasis can have a serious impact even if it involves a small area, such as the palms of the hands or soles of the feet.
Nearly one-quarter of people with psoriasis have cases that are considered moderate to severe (generally meaning it covers more than 3 percent of their body)
More than 1.5 million Americans have moderate to severe psoriasis
Severe types of psoriasis can compromise the skin's ability to control body temperature and prevent infections

QUALITY OF LIFE IMPACT (based on results of National Psoriasis Foundation 2001 Benchmark Survey on Psoriasis & Psoriatic Arthritis)

75 percent of people with moderate to severe psoriasis report that their disease has a moderate to large impact on their everyday lives:
26 percent alter their normal daily activities
21 percent stop their normal daily activities
40 percent say their psoriasis affects clothing choices (avoiding dark colors, covering up arms & legs)
36 percent say it affects how they sleep
36 percent report bathing more than normal


Psoriasis may disqualify a person from serving in the U.S. military


About 1 million people in the U.S. population have psoriatic arthritis; that equals about 0.5 percent of the country
Between 10 percent and 30 percent of people with psoriasis develop psoriatic arthritis
Psoriatic arthritis usually develops between the ages of 30 and 50, but it can develop at any time
Generally psoriasis appears before the psoriatic arthritis, but it can develop without the characteristic skin lesions
There are five types of psoriatic arthritis


Psoriasis patients make nearly 2.4 million visits to dermatologists each year
Overall costs of treating psoriasis may exceed $3 billion annually
150,000 to 260,000 cases of psoriasis are diagnosed each year


If one parent has psoriasis, children have a 10 percent chance of developing psoriasis
If both parents have psoriasis, children have a 50 percent chance


Psoriasis affects an estimated 1 percent to 3 percent of the world's population

*Data from the National Psoriasis Foundation