Psoriatic arthritis
What is psoriatic arthritis?
Psoriatic arthritis is a painful, inflammatory condition of the joints that usually (but not always) occurs in association with psoriasis of the skin. Up to 40% of people with skin psoriasis have some signs of psoriatic arthritis.
Symptoms of psoriatic arthritis come and go but it is a lifelong condition. It may result in severe damage to the joints and can be as severe as rheumatoid arthritis. Joint deformity and changes on X-rays may be found in approximately 40% of people with psoriatic arthritis.
People with severe psoriatic arthritis have been reported to have a shorter lifespan than average. This correlates with the severity of the joint disease.
Psoriatic arthritis belongs to a group of arthritic conditions called the spondyloarthropathies. Conditions included in this group have similar features and include:
- Psoriatic arthritis
- Ankylosing spondylitis
- Reactive arthritis
- Enteropathic arthropathy
Common features of the above four conditions include:
- Arthritis affecting joints of the arms and legs in an asymmetrical distribution
- Arthritis of the spine, hips and shoulders
- Negative rheumatoid factor (a blood test abnormality that is usually positive in patients with rheumatoid arthritis)
- Genetic susceptibility to the condition
- Distinctive features on X-rays
- Increased prevalence in males
