There are many terms used to describe chronic arthritis in children. These include juvenile rheumatoid arthritis, juvenile chronic arthritis, and juvenile idiopathic arthritis (JIA). Of these, JIA is used most often by specialists in pediatric rheumatology.
About one child in every 1,000 develops some type of juvenile arthritis. These disorders can affect children at any age, although rarely in the first six months of life. It is estimated that around 300,000 children in the U.S. have been diagnosed with JIA.
There are several types of JIA, all involving chronic joint inflammation. This inflammation begins before patients reach the age of 16, and symptoms must last from six weeks to three months in order to be called chronic. JIA may involve one or many joints and can cause other symptoms, such as fevers, rash, and eye inflammation.
Types of JIA include:
- Systemic onset JIA,which affects about 10% of children with arthritis. It begins with repeating fevers, often accompanied by a pink rash that comes and goes. It may cause inflammation of the internal organs as well as the joints.
- Oligoarticular JIA, which involves fewer than five joints in its first stages and affects about half of all children with arthritis. Girls have a higher risk than boys. Children who develop this form of JIA when they are younger than seven years old have the best chance of having their joint disease subside with time, but they are at increased risk of developing an inflammatory eye problem.
- Polyarticular JIA, which affects five or more joints and can begin at any age. Children diagnosed with polyarticular JIA in their teens may actually have the adult form of RA at an earlier than usual age.
- Psoriatic JIA, which is diagnosed when children have both arthritis and psoriasis—or a strong family history of psoriasis.
- Enthesitis related JIA, which often involves attachments of ligaments as well as the spine. These children more often have joint pain without obvious swelling and may complain of back pain and stiffness.
It is not known what causes the immune system to malfunction in JIA. Malfunctioning of the immune system in JIA targets the lining of the joint, known as the synovial membrane. This causes inflammation. When the inflammation persists, joint damage may occur. According to patient–fact sheet writer Leslie S. Abramson, MD, “Research suggests that some individuals have a genetic tendency to JIA but develop the condition only after exposure to an infection or other unknown trigger.”
JIA may be difficult to diagnose because some children may not complain of pain at first, and joint swelling may not be immediately obvious. There is no blood test that can be used to diagnose the condition. As a result, diagnosis of JIA depends on physicals, medical history, and the elimination of other diagnoses. Other conditions can look like JIA—including infections, childhood cancer, bone disorders, Lyme disease, and lupus—and these must also be ruled out before a diagnosis of JIA can be confirmed.
The overall treatment goal is to control symptoms, prevent joint damage, and maintain function. The first line of treatment involves a nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen or naproxen, administered in a dose appropriate for the child. Younger children may be given liquid preparations or medications that require less frequent use. Disease-modifying drugs are added as a second-line treatment when arthritis does not respond to NSAID therapy. “Some of these medications have been FDA [Food and Drug Administration] approved only for adults, but clinical trials are underway to test their effectiveness and safety in children,” says Dr. Abramson. Children whose joint swelling persists and who test positive for rheumatoid factor are more likely to develop joint damage and may require more aggressive treatments.
Because it is not known what causes JIA, it is not known how to prevent these conditions. In every instance, early diagnosis and treatment can help avoid joint damage. Growing up with arthritis can be challenging. However, with care from a team of rheumatology health professionals, most children with arthritis live full and active lives.
Download the complete juvenile arthritis fact sheet and other patient education materials at www.rheumatology.org by following the links to patient education from the Practice Support Menu.
