Early Juvenile Idiopathic Arthritis

Early juvenile idiopathic arthritis (JIA) is important to recognize as timely diagnosis and treatment improves prognosis. It is a misconception that complications of JIA arise only from long-standing disease and that children will outgrow it. Early aggressive treatment is the paradigm as early disease activity has long-term consequences. There are predictors of persistent disease and joint erosions that may identify patients at higher risk. Control of disease activity within the first 6 months of onset confers improved clinical course and outcomes. The treatment perspective is thus one of early aggressive treatment for induction of disease control and ultimately remission.

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Early juvenile idiopathic arthritis (JIA) may have a subtle presentation and be difficult to diagnose.
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The timely diagnosis and treatment of early JIA improves prognosis.
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Disease activity, even early in the course of JIA, can cause joint damage and long-term consequences. However, control of disease activity in the first 6 months of disease improves long-term prognosis.
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There are predictors of persistent disease and joint erosions early in the disease process of JIA that may identify patients who require more aggressive therapy.
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Early aggressive therapy of JIA for rapid disease control and remission is the goal of treatment.

Key Points

Juvenile idiopathic arthritis (JIA) is a chronic immunoinflammatory disease defined by the International League of Associations for Rheumatology (ILAR) criteria as arthritis in one or more joints that begins before the 16th birthday, persists for at least 6 weeks, and excludes all other known conditions. Classification criteria rely on the characteristics of the disease at onset and during its course and include seven subgroups ( Table 1 ). The early course of JIA influences whether active disease persists into adulthood. In addition, adults whose JIA is in remission suffer the physical and psychosocial consequences that stem not only from the chronicity of their condition and treatment but also from the earliest stages of their disease. Outcome studies have underlined the importance of early diagnosis and early aggressive treatment in improving prognosis.

Table 1

ILAR classification criteria for juvenile idiopathic arthritis

Subtype	Criteria	Exclusions
Oligoarthritis Persistent Extended	Arthritis in 4 or fewer joints during first 6 mo of disease Never more than 4 joints affected Greater than 4 joints affected after 6 mo of disease	(A) Psoriasis or history of psoriasis in the patient or first degree relative (B) Arthritis in an HLA-B27–positive male beginning after the sixth birthday (C) AS, ERA, sacroiliitis with IBD, Reiter syndrome, or acute anterior uveitis or a history of 1 of these disorders in a first-degree relative (D) Presence of IgM RF on at least 2 occasions at least 3 mo apart (E) Presence of systemic arthritis
Polyarthritis RF Negative	Arthritis affecting 5 or more joints during first 6 mo of disease RF test is negative	Exclusions A, B, C, D, E
Polyarthritis RF Positive	Arthritis affecting 5 or more joints during first 6 mo of disease 2 or more tests of RF at least 3 mo apart are positive	Exclusions A, B, C, E
Systemic	Arthritis in any number of joints together with a fever of at least 2 wk duration that is documented to be daily (quotidian) for at least 3 d and is accompanied by one or more of the following: Evanescent rash, generalized lymphadenopathy, enlargement of liver or spleen, serositis	Exclusions A, B, C, D
ERA	Arthritis and enthesitis or arthritis or enthesitis with at least two of the following: Sacroiliac joint tenderness and/or inflammatory spinal pain, positive HLA-B27, family history in at least one first or second-degree relative with medically confirmed HLA-B27–associated disease, anterior uveitis that is usually associated with pain, redness, or photophobia, onset of arthritis in a boy after 6 y of age	Psoriasis in at least one first- or second-degree relative Presence of systemic arthritis
Juvenile psoriatic arthritis	Arthritis plus psoriasis, or arthritis plus at least two of the following: dactylitis, nail pits or onycholysis, psoriasis in a first-degree relative	Exclusions B, C, D, E Arthritis fulfilling two JIA categories
Undifferentiated arthritis	Fulfills criteria in no category or in 2 or more categories	—