The cause of psoriatic arthritis is unknown. There is some evidence that infection or trauma can play a role in the development of the disease. For example, psoriatic arthritis seems to flare up in people whose immune systems are affected by HIV infection. Also, heredity seems to play a role. Up to 40% of people with psoriatic arthritis have a family history of skin or joint disease. Certain genes seem to be involved in certain types of psoriatic arthritis. For example, the gene HLA-B27 has been associated with psoriatic spondylitis.
Symptoms
Symptoms include:
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A pink or dull-red, scaly skin rash occurring in patches, especially on the back of the arms, front of the legs and scalp
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Inflammation of the joints, especially in the fingers, toes or spine
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Morning joint stiffness
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Lower back pain
Psoriatic arthritis can affect other parts of the body. For example, fatigue and anemia are common in people with active psoriatic arthritis. Frequently, the arthritis is accompanied by inflammation of tendons and the spots where tendons attach to bones, such as in the heel or fingers.
