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Classification of Juvenile Arthritis

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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 of Associations for Rheumatology (ILAR) 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
Organization Classification Length of illness before diagnosis
International League of Associations for Rheumatology 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.)
6 weeks
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).

6 weeks
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
3 months

No matter the classification, children who have symptoms before age 16 are said to have juvenile arthritis.

Related Information


ByHealthwise Staff
Primary Medical Reviewer Susan C. Kim, MD - Pediatrics
E. Gregory Thompson, MD - Internal Medicine
Martin J. Gabica, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer John Pope, MD - Pediatrics

Current as ofOctober 10, 2017

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