Diagnostic Steps and Treatment Options for Juvenile Idiopathic Arthritis
Initial laboratory testing and disease-modifying antirheumatic drugs (DMARDs) are strongly recommended for the diagnosis and treatment of juvenile idiopathic arthritis, with methotrexate being the preferred conventional DMARD for most JIA subtypes. 1, 2
Initial Diagnostic Steps
Laboratory Testing
- Complete blood count (CBC)
- Liver function tests (LFTs)
- Renal function tests
- Inflammatory markers (ESR, CRP)
- Rheumatoid factor (RF)
- Anti-nuclear antibodies (ANA)
- HLA-B27 (especially for enthesitis-related arthritis)
Laboratory monitoring should follow this schedule 2:
- For patients on NSAIDs: CBC, LFTs, and renal function tests every 6-12 months
- For patients on methotrexate: CBC, LFTs, and renal function tests within 1-2 months of initiation and every 3-4 months thereafter
Imaging
- Plain radiographs of affected joints
- Ultrasound for detecting early synovitis
- MRI for detailed assessment of joint inflammation and damage, particularly useful for temporomandibular joint involvement
Treatment Algorithm for JIA
1. Initial Treatment Options
- NSAIDs: Trial of scheduled NSAIDs is conditionally recommended as part of initial therapy 1
- Intraarticular Glucocorticoid Injections:
- Strongly recommended as part of initial therapy
- Triamcinolone hexacetonide is strongly preferred over triamcinolone acetonide 1
- Oral Glucocorticoids:
- Conditionally recommended against as part of initial therapy for oligoarticular JIA
- May be used as bridging therapy (<3 months) during initiation or escalation of therapy in patients with high or moderate disease activity 1
2. Disease-Modifying Treatment
- Conventional synthetic DMARDs:
- Strongly recommended if inadequate response to NSAIDs and/or intraarticular glucocorticoids 1
- Methotrexate is conditionally recommended as the preferred agent over leflunomide, sulfasalazine, and hydroxychloroquine 1
- Subcutaneous methotrexate is conditionally recommended over oral methotrexate 1
- Use of folic/folinic acid in conjunction with methotrexate is strongly recommended 1
3. Biologic DMARDs (if inadequate response to conventional DMARDs)
- TNF inhibitors (etanercept, adalimumab, infliximab, golimumab)
- T-cell costimulation modulator (abatacept)
- IL-6 inhibitor (tocilizumab)
- IL-1 inhibitors (anakinra, canakinumab) - particularly for systemic JIA
Combination therapy with a DMARD is strongly recommended for infliximab and conditionally recommended for other biologics 1
4. Adjunctive Therapies
- Physical and occupational therapy: Conditionally recommended regardless of concomitant pharmacologic therapy 1
- Dietary recommendations:
- Discussion of healthy, age-appropriate diet is strongly recommended
- Use of a specific diet to treat JIA is strongly recommended against 1
Medication Monitoring
Methotrexate
- CBC, LFTs, and renal function tests within 1-2 months of initiation and every 3-4 months thereafter
- Decrease dose or withhold if clinically relevant elevation in LFTs or decreased neutrophil/platelet count 1, 2
Sulfasalazine
- CBC, LFTs, and renal function tests within 1-2 months of initiation and every 3-4 months thereafter
- Decrease dose or withhold if clinically relevant elevation in LFTs or decreased neutrophil/platelet count 1
Leflunomide
- Temporarily hold if ALT >3× upper limit of normal 2
Biologics
- TB screening prior to initiation and when there is concern for TB exposure 2
Special Considerations
JIA with Polyarthritis
- Initial therapy with a DMARD is strongly recommended over NSAID monotherapy 1
- Using methotrexate monotherapy as initial therapy is conditionally recommended over triple DMARD therapy 1
- For patients with moderate/high disease activity receiving DMARD monotherapy:
- Adding a biologic to original DMARD is conditionally recommended over changing to a second DMARD or triple DMARD therapy 1
JIA with Systemic Features
- IL-1 or IL-6 inhibitors are recommended as first-line therapy 1, 3
- Monitor closely for macrophage activation syndrome (MAS), which occurs in approximately 28.6% of systemic JIA patients 3
Immunizations
- Inactivated vaccines are recommended for all JIA patients
- Live vaccines should be avoided in patients on biologic DMARDs 4
Treatment Efficacy Monitoring
- Use validated disease activity measures to facilitate treat-to-target approach 1
- Aim for low disease activity (cJADAS-10 ≤2.5) or remission
- Consider escalation of therapy if low disease activity is not achieved 1
Early aggressive treatment is critical to prevent joint damage and improve long-term outcomes in JIA. The treatment approach should be guided by disease subtype, severity, and response to therapy.