Juvenile idiopathic arthritis (JIA), also known as juvenile rheumatoid arthritis (JRA), is the most common form of arthritis in children ages 6 months to 17 years. JIA causes inflammation (redness, swelling, heat, pain) in one, or many, joints (areas of the body where two bones fit together). JIA is not the same as the adult type of arthritis. There are seven different types of JIA (see related conditions below).
JIA causes pain, stiffness, swelling, and redness most commonly in the knees and joints of hands and feet. The joint may not move fully (decreased range of motion). Symptoms are usually worse in the morning or after a nap. The symptoms may go away after a few months or be lifelong. Some types of JIA can affect other parts of the body, causing swollen lymph nodes, rashes and fever, eye inflammation and growth problems.
The cause of JIA is unknown (idiopathic). However, it is believed that both environmental and genetic factors play a role. JIA may be an autoimmune or autoinflammatory disease. Usually, our immune system protects us from illness and infection by attacking viruses, bacteria and other foreign bodies. Sometimes our immune system attacks its own healthy cells. Different parts of our immune system can go wrong causing either an autoimmune or an autoinflammatory response.
Girls are more likely to have JIA. Certain viruses may also increase a child’s risk. To diagnose this condition, your child’s doctor or specialist may perform a physical exam, blood tests and special imaging tests of your child’s joints (using X-ray, MRI and video imaging). Although there is no cure for JIA, there are treatments that help reduce pain and swelling. These treatments include medications, therapy, and possibly surgery. If your child has been diagnosed with JIA, talk with their doctor about the most current treatment options. Support groups are also a good source of information and will help connect you with other families.