Juvenile rheumatoid arthritis is joint inflammation and stiffness for more than 6 weeks in a child or teen aged 16 or younger. Inflammation causes redness, swelling, warmth, and soreness in the joints. But many children with JRA do not complain of joint pain.
The condition can affect any joint, and it may limit how well those joints work.
What Causes It?
JRA is an autoimmune disorder. This means that the immune system attacks healthy cells and tissues, causing inflammation.
Researchers don't know exactly why it happens. They suspect that it's a two-step process. First, something in a child’s genes makes them more likely to develop JRA. Then something else, such as a virus, triggers the disease.
How Is Juvenile Rheumatoid Arthritis Different from Adult RA?
The main difference is that some people with JRA outgrow the illness. Adults with RA usually have lifelong symptoms. Studies show that by adulthood, JRA symptoms disappear in more than half of all affected children.