M08.26: Juvenile arthritis with systemic onset Lower leg

You have a rheumatic disorder that is causing inflammation in your knee joint.

The rheumatic disorder appeared before you were 16.

A rheumatic disease can affect the entire body. There may be inflammation in the bones, the connective tissue, and the joints. The symptoms can be more and less severe. It is thought that rheumatic diseases are caused by a person’s immune system producing antibodies against their own body. These antibodies attack the body’s own tissue. The tissue can get inflamed and damaged as a result.

You have an inflamed joint in your knee.

The knee joint connects the thighbone (femur) to the lower leg. The kneecap is also part of the knee joint. There are 2 bones in the lower leg. These bones are called the tibia (shinbone) and fibula. There is also a joint immediately below the knee joint between the tibia and fibula.

An inflammation in the joints can cause various symptoms. Typical is a swollen, painful joint. The skin above the joint may also be red. It may also no longer be possible to move the joint as usual.

With this disorder, the joint inflammation may be accompanied by a fever lasting weeks. The condition can also affect inner organs. The skin may be red in many places.