What causes psoriatic arthritis?

The exact cause of psoriatic arthritis is unknown. An unknown trigger causes an abnormal response of your body’s immune system.1,2

Instead of just attacking the bugs that could make you ill, the immune system mistakenly attacks your skin and joints. The inflammation in psoriatic arthritis leads to skin symptoms and joint swelling, pain and stiffness.1,2 Why the immune system makes this mistake is unclear. Some additional factors that may influence whether someone is at risk of psoriatic arthritis are:2

Genetics – many people with psoriatic arthritis have family members who are also affected by the condition or by psoriasis

Environmental factors – exposure to environmental factors such as certain types of infections and physical injury can increase the risk of developing psoriatic arthritis

References
  1. American College of Rheumatology. Psoriatic arthritis. Available at: www.rheumatology.org/Practice/Clinical/Patients/Diseases_And_Conditions/Psoriatic_Arthritis/ [Last accessed: November 2017].
  2. Fitzgerald O. 2013. Psoriatic arthritis. In: Firestein GS, et al. Kelley’s Textbook of Rheumatology. Philadelphia: Elsevier, 1232–1268.