Classification of Juvenile Arthritis - Topic Overview
There used to be two ways to classify juvenile arthritis. There was the European classification of juvenile chronic arthritis (JCA). And there was the American classification of juvenile rheumatoid arthritis (JRA). Each system used different categories. This made it hard to use European and American research findings and treatment guidelines together.
To improve research and treatment, the International League Against Rheumatism has devised a set of international criteria that uses the term "juvenile idiopathic arthritis" (JIA). The word "idiopathic" means "of unknown cause." This approach is now used by most researchers and health professionals.
The table below summarizes the three systems.
Classification systems for juvenile arthritis
|| Length of illness before diagnosis
|International League Against Rheumatism
||Juvenile idiopathic arthritis (JIA)
- Systemic JIA
- Polyarticular JIA, RF-positive
- Polyarticular JIA, RF-negative
- Oligoarticular JIA
- Persistent. It affects 1 to 4 joints.
- Extended. Over time it affects 5 or more joints.
- Psoriatic arthritis
- Enthesis-related arthritis
- Other arthritis (This is also called undifferentiated or unclassified arthritis.)
|American College of Rheumatology
Juvenile rheumatoid arthritis (JRA)
- Systemic JRA
- Polyarticular JRA. It affects 5 or more joints.
- Oligoarticular JRA. It affects 1 to 4 joints.
JRA does not include similar types of childhood arthritis (juvenile ankylosing spondylitis, juvenile psoriatic arthritis).
|European League Against Rheumatism
|| Juvenile chronic arthritis (JCA)
- Systemic JCA
- Polyarticular JCA. It affects 5 or more joints and is RF-negative.
- Juvenile rheumatoid arthritis. It affects 5 or more joints and is RF-positive.
- Oligoarticular JCA. It affects 1 to 4 joints.
- Juvenile psoriatic arthritis
- Juvenile ankylosing spondylitis
No matter the classification, children who have symptoms before age16 are said to have juvenile arthritis.