What is JRA? People sometimes think that Juvenile Rheumatoid Arthritis is the diagnosis when kids get Rheumatoid Arthritis, but that isn’t accurate. Some children with JRA have a disease like adult RA, but most JRA is different than the adult version of rheumatoid arthritis.
The term “JRA” was used in North America in the past (in Europe “JCA” for juvenile chronic arthritis was used), but current terminology is JIA.
There are three main diseases categorized as JRA:
About one-fifth of kids with JRA have systemic onset juvenile rheumatoid arthritis, which in the past has been called Still’s Disease and is now called systemic-onset juvenile idiopathic arthritis. In addition to joint pain and swelling, this type of JRA is noted for high fevers and a salmon-colored rash. The liver, spleen, heart, and digestive tract can also be affected by this form of JRA.
About half of kids with JRA have fewer than five joints affected. Formerly called pauciarticular juvenile rheumatoid arthritis, this is now called oligoarthritis. It tends to affect the larger joints such as knees, hips, shoulders, and elbows. The eyes can also be affected, so referral to an ophtholmologist is important.
Three-tenths of children with JRA have five or more joints affected. This type of JRA is categorized as polyarticular juvenile rheumatoid arthritis. Polyarticular is the form of JRA that most closely resembles adult-onset RA; in some cases it can be identical. The new JIA classification system distinguishes between RF+ and RF- (those whose laboratory tests show a positive rheumatoid factor, vs those whose lab results are negative for rheumatoid factor).
There are other types of juvenile arthritis that are classified at JIA, but didn’t qualify under the JRA criteria.
For more information about the different types of JRA and how they are treated, see: