Rheumatoid arthritis is a long-term autoimmune disease. The immune system confuses foreign substances with healthy tissue, which causes the body to attack itself. RA leads to chronic joint inflammation, and can also affect surrounding tissues of the joints and other organs.

RA is more common in adults, but it can affect children as well. In adults, the condition is known as Adult Onset RA. In children, it’s called Juvenile RA (JRA), and includes three different types:


  • Most common type, affects 50% of children with JRA
  • Involves 1-4 joints, usually large ones
  • Mostly affects girls under eight years old


  • Affects 30% of children with JRA
  • Involves more than 4 joints, including large and small ones
  • Usually occurs on both sides of the body

Systemic – Still’s Disease

  • Affects 20% of children with JRA
  • Causes inflammation surrounding the lungs and heart, swollen lymph nodes and joints, and high fevers