What is JIA ?

Juvenile Idiopathic Arthritis (JIA) is a long-term condition. It means that there is inflammation in one or more joints, which is not caused by an infection or injury. Symptoms begin before the age of 16.

JIA is an autoimmune condition. This is where the body’s natural immune system, which is designed to fight infections, starts attacking the joints by mistake. If this is not stopped, the joints become damaged. Current treatments try to reduce the immune system to prevent joint damage happening.

Children with JIA have inflamed joints. They are sometimes swollen or warm to the touch, but sometimes inflammation is hard to spot. Their joints may be painful, and they may have reduced mobility. With younger children it can be difficult to tell if joints are painful or if your child is able to move them less than they could, so a general rule is to look for change: Is your child now not able to do something that they could before (such as sitting on the floor, walking, writing with a pencil)? If so, it could be because their joints are sore or less mobile.

You can download a copy of My JIA, a comprehensive guide to life with JIA, packed full of information for that will help you and your child on your own journey with JIA. It includes a section about schools, so be sure to share a copy with your child's school so they know how they can support your child.

Children with JIA can also develop uveitis, which is inflammation of part of the eye. There are often no symptoms, but uveitis can cause permanent sight loss. It is very important that children who have JIA have specialist eye tests that can detect uveitis on a regular basis. Find out more about uveitis here.

The cause of JIA is not yet known, but there is a genetic link. However, just because someone has JIA or another autoimmune condition, does not mean that their children will also develop the condition. But it does make it more likely. There also has to be a trigger – something that starts the immune system attacking the joints. There are many things that could become a trigger, and it is not possible to avoid them all. They include injuries and injections, which everyone has at some point. Not everyone who encounters a trigger will develop JIA. The exact reason for JIA developing is not yet known.