Skip to Content

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 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 ReviewerSusan C. Kim, MD - Pediatrics
E. Gregory Thompson, MD - Internal Medicine
Martin J. Gabica, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Specialist Medical ReviewerJohn Pope, MD - Pediatrics

Current as ofOctober 10, 2017

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use and Privacy Policy. Learn how we develop our content.

© 1995-2018 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

Symptom Checker

Feeling under the weather?

Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.

Symptom Checker

Decision Points

Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.

You'll find Decision Points to help you answer questions about:

Interactive Tools

Get started learning more about your health!

Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.

Health Library