psoriatic arthritis

Psoriatic arthritis is an  autoimune disease  meaning that your cells and antibodies (part of your mmune system fight your own tissues. Rarely, a person can have psoriatic arthritis without having obvious psoriasis. Usually, the more severe the skin symptoms are, the greater the likelihood a person will have psoriatic arthritis.
Psoriasis affects 2.5% of white people in North America. It is less common in African American and Native American people. Psoriatic arthritis affects 5-8% of people with psoriasis. A recent survey by the Naional Proriasis Foundation indicated that approximately 1 million people in the United States have psoriatic arthritis. Many people who have psoriasis may not know that they have psoriatic arthritis.