Psoriasis is a chronic skin disorder that causes scaling and inflammation.
Psoriasis may develop as a result of an abnormality in the body's immune system. The immune system normally fights infection and allergic reactions.
Psoriasis probably has a genetic component. Nearly half of patients have family members with psoriasis.
Certain medications may trigger psoriasis. Other medications seem to make psoriasis worse in people who have the disease.
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