Juvenile Idiopathic Arthritis (JIA) Explained
What is JIA?
JIA is a condition characterized by joint inflammation and stiffness for more than 6 weeks in a child of 16 years or younger. Inflammation causes redness, swelling, warmth, and soreness in the joints, although many children with JIA do not complain of joint pain. Any joint can be affected and inflammation may limit the mobility of affected joints. In polyarticular-course JIA, five or more joints are affected. The small joints, such as those in the hands and feet, are most commonly involved, but JIA may also affect large joints.
A disease of the immune system
JIA is a disease of the immune system. In JIA, the immune system attacks the body's own healthy cells, mistaking them for cells that don't normally belong to the body. This causes inflammation in the lining and connective tissues of the joints.
Who gets JIA?
JIA affects 1 in 1,000 Canadian children under the age of 16. Generally, it affects girls more than boys. JIA itself is not inherited. What can be inherited are the genes that may make someone more likely to develop the disease, including those genes that control your immune system, although scientists believe it is unlikely that genetics alone bring about JIA.
