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CHAPTER 11  |  Juvenile Idiopathic Arthritis

Comparison of JRA, JCA, and JIA Classifications

TABLE 11-1

JRA

JCA

JIA

Committee Age at onset

ACR

EULAR < 16 yr > 3 mo

ILAR

< 16 yr > 6 wk

< 16 yr > 6 wk

Disease duration

Onset types

Pauciarticular Polyarticular Systemic

Pauciarticular Polyarticular RF-negative Juvenile rheumatoid arthritis Systemic Juvenile psoriatic arthritis Juvenile ankylosing spondylitis

Oligoarticular, persistent Oligoarticular, extended Polyarticular RF-negative Polyarticular RF-positive Systemic Psoriatic arthritis Enthesitis-related arthritis

Exclusions

Juvenile psoriatic arthritis Juvenile ankylosing spondylitis Inflammatory bowel disease Other forms of juvenile ­arthritis

Other forms of juvenile arthritis

Other forms of juvenile arthritis

RF, rheumatoid factor.

Criteria for Classification of JIA

TABLE 11-2

Exclusions a

Inclusion Criteria b

JIA Subtype Oligoarthritis  Persistent  Extended

1–5

≤ 4 joints during disease course > 4 joints after the first 6 mo

Arthritis affecting ≥ 5 joints during the first 6 mo Arthritis affecting ≥ 5 joints during the first 6 mo, plus RF positivity on two occasions more than 3 mo apart

Polyarthritis RF-negative Polyarthritis RF-positive

1–5

1–3, 5

Systemic

1–4

Arthritis with or preceded by daily fever of at least 2 weeks’ duration, accompanied by one or more of the following:  Evanescent, nonfixed erythematous rash  Generalized adenopathy  Hepatomegaly or splenomegaly  Serositis Arthritis and psoriasis, or arthritis and at least two of the following: a. Dactylitis b. Nail abnormalities (pitting or onycholysis) c. Family history of psoriasis in a first-degree relative Arthritis and enthesitis, or arthritis or enthesitis with at least two of the following: 1. SI joint tenderness and/or inflammatory spinal pain 2. Presence of HLA-B27 3. Family history of HLA-B27–associated disease in a first-degree ­relative 4. Onset of arthritis in a male after the age of 6 yr Children with arthritis of unknown cause that persists ≥ 6 wk Does not fulfill criteria for any of the other categories Fulfills criteria for ≥ 1 of the other categories

Psoriatic

2–5

Enthesitis-related

1, 4, 5

Undifferentiated

a Exclusions: 1, psoriasis in the patient or a first-degree relative; 2, arthritis in an HLA-B27 positive male beginning after the sixth birthday; 3, ankylosing spondylitis, enthesitis-related arthritis, sacroiliitis with IBD, Reiter syndrome, or acute anterior uveitis in a ­first-degree relative; 4, IgM RF on at least two occasions more than 3 mo apart; 5, presence of systemic JIA. b Inclusion criteria for all subtypes: 1, age at onset < 16 yr; 2, arthritis in one or more joints; 3, duration of disease is at least 6 wk. From Petty RE, et al. International League of Associations for Rheumatology classification of juvenile idiopathic arthritis: second revision, Edmonton, 2001. J Rheumatol 2004;31(2):390–392.