Juvenile rheumatoid arthritis (JRA) is the most common form of arthritis in children. As many as half of the children with this condition have a mild form and have few problems. However, some forms of this disease can produce long-term problems. JRA is often called juvenile idiopathic arthritis (JIA).
There are three types of JRA:
The cause of JRA is not completely known. Research shows that it is an autoimmune disease. In an autoimmune disease, your body loses the ability to tell the difference between healthy cells and harmful invaders, such as bacteria and viruses. Instead of protecting your body, your immune system releases chemicals that damage healthy tissues and cause swelling and pain.
Juvenile rheumatoid arthritis has similar symptoms to the adult forms of arthritis such as pain, swelling, stiffness, and loss of motion to joints. When the arthritis starts and how severe the symptoms are varies among the different types of JRA. As with adult-onset disease, JRA may flare and then settle into remission.
A growing child with juvenile rheumatoid arthritis may have abnormal bone growth. Also, if a child keeps a joint from moving to avoid pain, this lack of movement can weaken and shorten muscles, causing a deformity over time.
Your healthcare provider may suspect JRA if your child has been complaining of joint pain and stiffness for more than 6 weeks. Tests that may be ordered depending on the symptoms. Your healthcare provider may do tests that check for inflammation or autoimmunity (an "ANA" test). Some children also have a rheumatoid factor test.
The outlook for juvenile rheumatoid arthritis is often better than that for an adult with arthritis. About half of children affected by JRA recover completely and outgrow the arthritis by adulthood. Eye problems may continue for some children even if their joint symptoms have gone away. Joint problems can sometimes return after long periods without symptoms. The fewer the number of joints affected, the better the outlook.
A small percentage of children with systemic onset JRA develop severe arthritis in many joints that can continue to adulthood.
Corticosteroids may be used to reduce severe pain and swelling. These medicines are effective, but can have serious side effects, such as interfering with normal growth.
Disease-modifying antirheumatic drugs (DMARDs) may be used if rest, exercise, use of NSAIDs, and physical therapy do not work. However, there are some problems with DMARDs. They may take 2 to 6 months to start working. They may cause serious side effects on blood cells, eyes, kidney, or liver.
A new class of medicines that block a protein (called "TNF") is used to treat some children with severe JRA. These medicines are antibodies and are given by injection. Some children have had serious side effects while using these medicines.
Discuss the risks and benefits of immunosuppressive and corticosteroid medicines with your healthcare provider. A pharmacist may provide helpful information about all of these medicines.