What is the recommended treatment for a pediatric patient with juvenile idiopathic arthritis (JIA)?

Treatment of Juvenile Idiopathic Arthritis

The treatment approach for JIA follows a stepwise algorithm based on disease subtype, with NSAIDs and/or intraarticular glucocorticoid injections as initial therapy, followed by methotrexate as first-line DMARD, and biologic DMARDs reserved for inadequate response to conventional therapy. 1, 2

Initial Treatment by JIA Subtype

Oligoarticular JIA

• Start with scheduled NSAIDs (not as-needed dosing) as part of initial therapy 1, 2, 3
• Intraarticular glucocorticoid injections (IAGCs) are strongly recommended as part of initial therapy 1, 2
• Triamcinolone hexacetonide is the preferred steroid for intraarticular injection 3
• Oral glucocorticoids are conditionally recommended against as initial therapy 1, 2

Polyarticular JIA

• Initial therapy with a DMARD is strongly recommended over NSAID monotherapy 2
• Methotrexate monotherapy is conditionally recommended as initial therapy, with subcutaneous route preferred over oral 2
• For patients with high-risk features (high-risk joint involvement, high disease activity, or risk of disabling joint damage), initial biologic therapy may be considered 2
• NSAIDs serve as adjunct therapy for symptom control 2, 3

Systemic JIA (without Macrophage Activation Syndrome)

• NSAIDs are conditionally recommended as initial monotherapy 1, 2, 3
• Oral glucocorticoids are conditionally recommended against as initial monotherapy 2, 3
• Conventional synthetic DMARDs are strongly recommended against as initial monotherapy 2, 3
• IL-1 and IL-6 inhibitors are strongly recommended over conventional synthetic DMARDs for inadequate response to NSAIDs and/or glucocorticoids 2

Escalation Algorithm for Inadequate Response

For Oligoarticular JIA

1. If inadequate response to NSAIDs and/or IAGCs: Add conventional synthetic DMARDs (strongly recommended) 1, 2
2. Methotrexate is conditionally recommended as the preferred csDMARD over leflunomide, sulfasalazine, or hydroxychloroquine 1, 2
3. If inadequate response to NSAIDs/IAGCs plus at least one csDMARD: Add biologic DMARDs (strongly recommended) 1, 2
4. There is no preferred biologic DMARD 1

For Polyarticular JIA with Persistent Disease Activity

• For low disease activity (cJADAS10 ≤2.5 with ≥1 active joint): Escalating therapy is conditionally recommended, with options including IAGCs, DMARD dose optimization, methotrexate trial if not done, or adding/changing biologic 2
• For moderate/high disease activity (cJADAS10 >2.5): Adding a biologic to original DMARD is conditionally recommended over changing to a second DMARD or triple DMARD therapy 2
• When switching biologics: Switching to a non-TNF biologic (tocilizumab or abatacept) is conditionally recommended over switching to a second TNF inhibitor 2

For Systemic JIA with Residual Arthritis

• Biologic DMARDs or csDMARDs are strongly recommended over long-term glucocorticoids for incomplete response to IL-1 and/or IL-6 inhibitors 2

Specific Medication Considerations

NSAIDs

• Naproxen is the preferred NSAID due to established efficacy and safety profile 4
• An adequate trial period is at least 8 weeks 4
• NSAIDs should not delay introduction of DMARDs like methotrexate 4

Methotrexate

• An adequate trial of methotrexate is 3 months 2
• However, if no or minimal response after 6-8 weeks, changing or adding therapy is appropriate 2
• Subcutaneous methotrexate is preferred over oral for polyarticular JIA 2

Biologic DMARDs

• Etanercept (Enbrel) is FDA-approved for polyarticular JIA in patients ≥2 years at 0.8 mg/kg weekly (max 50 mg) for weight <63 kg, or 50 mg weekly for weight ≥63 kg 5
• Adalimumab (Humira) is FDA-approved for polyarticular JIA in patients ≥2 years: 10 mg every other week (10-15 kg), 20 mg every other week (15-30 kg), or 40 mg every other week (≥30 kg) 6
• Methotrexate, glucocorticoids, NSAIDs, and/or analgesics may be continued during biologic treatment 5, 6

Critical Treatment Principles

Disease Activity Monitoring

• Use validated disease activity measures (such as cJADAS-10) to guide treatment decisions and facilitate treat-to-target approaches 1, 2, 3
• Low disease activity is defined as cJADAS-10 ≤2.5 with ≥1 active joint 3
• Moderate/high disease activity is defined as cJADAS-10 >2.5 3

Poor Prognostic Features

• Consider poor prognostic features to guide treatment escalation, including: ankle/wrist/hip/sacroiliac joint/TMJ involvement, erosive disease, enthesitis, delay in diagnosis, elevated inflammation markers, and symmetric disease 1, 2, 3

Glucocorticoid Use

• Prolonged oral glucocorticoids as monotherapy should be avoided 2, 3
• Short-term bridging with oral glucocorticoids (<3 months) may be used during initiation of therapy if high disease activity, limited mobility, or significant symptoms are present 3

Common Pitfalls to Avoid

• Do not dismiss insidious onset joint pain as simple overuse without ruling out inflammatory arthritis, as early DMARD therapy is crucial to prevent permanent joint damage 3
• Do not use aspirin in children with JIA due to safety concerns and risk of Reye's syndrome 4
• Do not delay methotrexate initiation while waiting for NSAID response in polyarticular JIA 2, 4
• Do not continue NSAID monotherapy beyond 8 weeks without disease-modifying therapy in patients with persistent active disease 4

Adjunctive Therapies

• Physical therapy and/or occupational therapy are conditionally recommended for children who have or are at risk for functional limitations 3