Children sometimes complain about aches in their joints. A joint is where the ends of bones meet, such as the knee joint, shoulder joint, or the small joints in the fingers and toes. Joint pain in children can be caused by a variety of things. But if a child's joints are swollen for 6 weeks in a row or longer, he or she may have juvenile arthritis (JA).
Juvenile arthritis is a long-lasting, chronic disease. It is the most common form of arthritis in children. In the United States, it affects nearly 250,000 children under the age of 16 years.
There are several types of juvenile arthritis. Nearly all of them are different from rheumatoid arthritis in adults. This is why the term "juvenile rheumatoid arthritis (JRA)" is no longer widely used.
Description
Juvenile arthritis is an autoimmune disease. This means that the body attacks its own healthy cells and tissues. Arthritis results from ongoing joint inflammation in four steps:
The joint becomes inflamed
The joint stiffens (contracture)
The joint suffers damage
The joint's growth is changed
In some cases, symptoms of juvenile arthritis are mild and do not progress to more severe joint disease and deformities. In severe cases, juvenile arthritis can produce serious joint and tissue damage. It can also cause problems with bone development and growth.
For many years it was believed that most children eventually outgrow juvenile arthritis. Now it is known that half of the children diagnosed with juvenile arthritis will continue to have active arthritis 10 years after diagnosis unless they receive aggressive treatment.