Most people think of arthritis as something older adults often suffer from. But juvenile idiopathic arthritis (JIA) affecting children is not uncommon. This condition used to be called juvenile rheumatoid arthritis (JRA) but new findings have shifted the name to reflect numerous subtypes of the disease.
First of all, who is affected by this potentially disabling disease? It first appears in children at a very young age (between one and three years old). It can develop later but rarely presents in babies before age six months. Early diagnosis and treatment can help prevent long-term complications but there is no cure. In some children, it disappears as mysteriously as it came. In others, active disease accompanies them right into adulthood.
What causes juvenile idiopathic arthritis (JIA)? No one knows for sure. There are probably multiple factors including genetics, confusion within the immune system, environmental agents, bacteria or viruses, trauma, and irregular hormone function. JIA is considered an autoimmune because the immune system fails to recognize self from nonself, identifies the joint as a foreign substance, and attacks itself.
How is it diagnosed? There isn’t one single individual lab test that can be relied upon to identify JIA as the underlying problem for all affected patients. That’s why doctors have to depend on the child’s symptoms, history (including family history), X-rays, and other imaging studies to make the diagnosis. There are a couple of blood tests that can help (e.g., presence of antinuclear antibodies or ANAs and rheumatoid factor (RF), but they aren’t positive in everyone.
There are seven subtypes of JIA. These include oligoarticular JIA, polyarticular RF-positive JIA, polyarticular RF-negative JIA, systemic JIA, psoriatic JIA, enthesitis-related or ERA arthritis, and finally, undifferentiated arthritis. These are listed in descending order of frequency. Oligoarticular JIA (affecting more than one joint) is the most common subtype. ERA and undifferentiated arthritis are much more rare.
You’ll want to find out which subtype your child has in order to find out more about the characteristics of that form. With this information, it will be easier to investigate what to expect, how to treat or manage it, and long-term prognosis.
Throughout the search to find out what’s wrong, the goal is to treat early and quickly in order to reduce pain, minimize joint damage, and help the child maintain a normal lifestyle. Adequate management over the course of the disease process is important in order to improve quality of life measures as well.