Psoriatic arthritis is found in patients with psoriasis, a chronic skin condition causing patches of thick, inflamed red skin, often covered with silvery scales.
The exact cause is unknown, but it is thought to be due to a combination of factors:
• genetic – often occurs in families
• immunologic – associated with various immune disorders (e.g. HIV)
• environmental factors – exposure to certain infections
• trauma – damaged skin or joints may be affected later
The joints affected by psoriatic arthritis vary in distribution, and there may also be joint destruction, nail pitting and eye problems (iritis or uveitis).
Heat, physiotherapy and exercise may help to relieve the pain and stiffness, but NSAIDs are the drugs which provide good relief initially. If these don’t work well enough, disease-modifying drugs such as methotrexate may be introduced under specialist supervision.
Psoriatic arthritis is the one form of arthritis in which cortisone use is not advised, as it may lead to pustular psoriasis, and may interfere with the effects of other medication. Surgery may be needed to replace joints which are badly damaged and have limited movement or function.