What is juvenile idiopathic arthritis?

Juvenile idiopathic arthritis (JIA) is an autoimmune disease that can cause inflammation, swelling, stiffness and pain in the joints

What you should know about JIA

Polyarticular JIA affects 5 or more joints, often the small joints of the fingers and hands, but weight- bearing joints and the jaw can also be affected.

  • JIA is the most common type of arthritis in children

  • It occurs more often in girls

  • It can cause inflammation, swelling, stiffness, and pain in the joints, as well as other symptoms, depending on the type of juvenile idiopathic arthritis a child has

  • It usually develops before age 16

  • It can be mild and short term – or it can be severe and cause permanent damage to joints

The symptoms of JIA

Symptoms of juvenile idiopathic arthritis can vary. They can be very different from one child to the next. And, even in the same child, symptoms can be different each day. Some common JIA symptoms are:

  • Painful, swollen, and tender joints

  • Joint stiffness that’s worse in the morning

What causes JIA?

The word “idiopathic” means “the cause is unknown.” But even though scientists and doctors don’t know the exact cause of JIA, they do know that it’s likely caused by a combination of factors:

  • Genetics
  • Environment
  • Immune system

Some children with JIA produce too much of certain proteins, including TNF. When too much TNF is produced, inflammation can result. This can contribute to symptoms of JIA such as joint pain, swelling, and stiffness.

Diagnosing JIA: It’s not so easy

There isn’t one specific test that can diagnose JIA, but doctors use a combination of the following methods to make a diagnosis:

  • Medical history

  • Physical exam

  • X-rays or magnetic resonance imaging (MRI)

  • Blood tests

  • Process of elimination—ruling out other conditions that can have similar symptoms

Getting the proper diagnosis and treatment is important. It can reduce the signs and symptoms of juvenile idiopathic arthritis.