Psoriatic arthritis is an inflammatory condition that affects the joints of children and adults with psoriasis. Psoriasis is a skin condition that causes patches of thick, red skin to form on certain areas of your body. Not everyone with psoriasis develops psoriatic arthritis, but everyone with psoriatic arthritis has psoriasis.
Most people develop the skin signs of psoriasis first and are later diagnosed with psoriatic arthritis. Joint pain in people with psoriatic arthritis can range from mild to severe. Many experience changing signs and symptoms as the disease continues.
Many definitions of psoriatic arthritis exist, which makes it hard to estimate how many people have the disease. About 10 percent to 15 percent of people with psoriasis eventually develop psoriatic arthritis. While no cure for psoriatic arthritis exists, doctors work to control your signs and symptoms and prevent damage to your joints.
The above information thankfully comes from the Mayo Clinic.com at the following link.