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Start free with EleplanPolyarticular juvenile idiopathic arthritis
ORPHA:404580Clinical group
Also called Juvenile polyarthritis · Juvenile polyarticular arthritis · Polyarticular JIA
What it is
A rare type of juvenile idiopathic arthritis characterized by arthritis with an onset prior to the age of 16 years persisting for longer than six weeks and affecting at least five joints during the first six months of the disease. Other possible causes of joint inflammation must be excluded. Two subgroups of the disease can be distinguished, based on the presence of absence of rheumatoid factor. Both subgroups are more common in girls and may be associated with mild fever, weight loss, anemia, moderate hepatosplenomegaly, and mild growth retardation.
Key facts
- Classified as
- Clinical group
Recorded for the broader condition
- Prevalence
- 1-5 / 10 000Juvenile idiopathic arthritis
- Age of onset
- ChildhoodJuvenile idiopathic arthritis
Orphanet records these for the broader condition rather than for this specific form. They are a starting point, not a figure for this subtype — subtypes often differ, and some are defined by being rarer than the condition they sit under.
Genes reported in subtypes
Orphanet records these genes on 1 more specific entry under this disorder, not on this entry itself:
A well-studied disease is usually split into subtypes, and the gene is curated on whichever one the evidence belongs to. Open a subtype to see which gene goes with it.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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