People with this condition have inflammation of the skin (psoriasis) and joints (arthritis).
Psoriasis causes patchy, raised, red, and white areas of inflamed skin with scales. It usually affects the tips of the elbows and knees, the scalp, the navel, and skin around the genital areas or anus.
Only about 10% to 30% of people with psoriasis will also get psoriatic arthritis.