Table 1 Juvenile idiopathic arthritis classification scheme
Category | Characteristics |
|---|---|
Systemic onset | Arthritis in one or more joints, 2 weeks of fever, plus ≥1 of: rash, hepatosplenomegaly, lymphadenopathy |
Oligoarthritis | Arthritis affecting one to four joints for first 6 months of disease: persistent, affects ≤4 joints throughout disease course; extended, affects >4 joints after the first 6 months |
Polyarthritis, rheumatoid factor-negative | Arthritis affecting five or more joints in the first 6 months, negative rheumatoid factor |
Polyarthritis, rheumatoid factor-positive | Arthritis affecting five or more joints in the first 6 months, positive rheumatoid factor (on two separate occasions at least 3 months apart) |
Psoriatic arthritis | Arthritis plus psoriasis in child – or two out of three of: dactylitis, nail pitting, psoriasis in first-degree relative |
Enthesitis-related arthritis | Arthritis and enthesitis – or arthritis or enthesitis and two out of: sacroiliac joint involvement, HLA-B27-positive, male >6 years, acute anterior uveitis, ankylosing spondylitis, inflammatory bowel disease plus sacroilitis in first-degree relative |
Undifferentiated arthritis | Arthritis not meeting criteria for one of above categories or fitting more than one of the above groups |