Statistically, about 10 percent of people with psoriasis develop a kind of arthritis known as psoriatic arthritis. Some physicians feel that psoriatic arthritis is even more common. Psoriatic arthritis causes pain, swelling and tenderness of the joints and the tissue around the joints. The joint may not move easily. Prompt treatment can relieve pain and inflammation and possibly help prevent joint destruction if severe arthritis is present.
Psoriatic arthritis is classified as different from other arthritic diseases.
Anyone can develop psoriasis, though heredity seems to play a role. There is a family association in one out of three cases. Psoriasis affects about 2 percent of the U.S. population and is less common in African-Americans and Asians. Psoriasis appears in men and women in equal number. There are no personality types that have been identified as being more likely to develop psoriasis.