What is inflammatory arthritis?

Inflammatory arthritis (IA) is joint inflammation caused by an overactive immune system. It usually affects many joints throughout the body at the same time. Inflammatory forms of arthritis are much less common than osteoarthritis (OA), which affects most people at the later stages of life.

What is the difference between osteoarthritis and inflammatory arthritis?

The major distinction between OA and IA is that:

  • Osteoarthritis is caused by physical use – wear and tear of a joint over time (or, occasionally, over a short time as a result of an injury).
  • Inflammatory arthritis is a chronic autoimmune disease in which your immune system misidentifies your own body tissues as harmful germs or pathogens and attacks them. The result is inflammation of the affected tissues in and around joints.

Because OA involves physical wear on joints in the body, it usually appears in people after the age of 50. The older you get, the more likely you are to get osteoarthritis.

Since inflammatory arthritis is a chronic disease, it affects people of all ages, often striking people in their peak working and child-rearing age. IA diseases can often be diagnosed in patients as young as age 20 or 30. Less commonly, kids and teens may be diagnosed with a form of childhood arthritis, such as juvenile idiopathic arthritis. IA is more common in females than in males, and it is not understood why.