Childhood arthritis is a disease that occurs in children under the age of 16. It causes pain, stiffness, and swelling in one or more of the joints. This pain, stiffness, and swelling are called inflammation. With childhood arthritis, the inflammation lasts longer than six weeks, and is not caused by an injury or other illness. Childhood arthritis is also called juvenile arthritis.

How common is childhood arthritis? It affects 1 in 1,000 US children under the age of 16. Both boys and girls are affected by childhood arthritis. Arthritis is not just a disease of old people. In fact, approximately one in 1,000 children under the age of 16 suffers from arthritis. Juvenile arthritis is among the most common chronic childhood disorders.

What causes childhood arthritis?

The exact cause of childhood arthritis is unknown. Childhood arthritis does not usually run in families and cannot be passed from one person to another. The onset of childhood arthritis may follow an infection or injury, but these events do not cause the arthritis. With childhood arthritis, the body's immune system stops working properly. The immune system's job is to fight off germs and disease. However, in a child with childhood arthritis the immune system attacks healthy tissues. What triggers this process is unknown.

What can you do about childhood arthritis? If your child has inflammation, in one or more joints for more than six weeks your doctor may perform a physical examination of your child and order tests, such as x-rays and blood tests to find out what is causing the inflammation. There is not just one single symptom, sign, or test that will give a diagnosis of childhood arthritis.

If your doctor thinks your child has childhood arthritis, he or she will usually refer your child to a rheumatologist (pronounced room-a-tol-o-jist). A rheumatologist is a doctor who has received special training in the diagnosis and treatment of problems involving inflammation of the joints, muscles and other parts of the body.