Name
ARTHRITIS, JUVENILE RHEUMATOID
DESCRIPTION
DETAIL
CAUSES: * Multifactorial including abnormal immune response, genetic predisposition and environmental triggers, possibly infectious -------------------------------------------------------------------------- DIFFERENTIAL DIAGNOSIS: * Other rheumatic diseases, especially SLE and dermatomyositis * atypical bacterial or viral infections * hemoglobinopathies * malignancy * vasculitis * rheumatic fever * Lyme disease * post-infectious arthritis * musculoskeletal * developmental abnormalities * pain syndromesβ’ WBC normal or markedly elevated (sys) β’ Hb normal or low (especially sys) β’ Platelet count normal or elevated β’ ANA positive, 40% (poly or pauci) β’ RF positive, 10-15% (usually polys) β’ HLA-B27 positive, 70% in pauci boys β’ Sedimentation rate (ESR) elevated in most patients with active disease; > 100 mL/hr (Westergren) in active systemic disease IMAGING: β’ Early radiographic changes - soft tissue swelling, periosteal reaction, juxta-articular demineralization; later changes include joint space loss, articular surface erosions, subchondral cyst formation, sclerosis and joint fusion β’ MRI very helpful in delineating early erosions DIAGNOSTIC PROCEDURES: β’ Joint fluid aspiration and analysis helpful in excluding infection β’ Synovial biopsy occasionally indicated in persistent, atypical monoarthritis
TYPENOTES
RISK FACTORS: HLA-B27 in pauci JRA increases risk for development of spondyloarthropathy β’ Rheumatoid factor positivity increases risk for severe arthritis in poly JRA β’ ANA positivity increases risk for uveitis in pauci and poly JRAAPPROPRIATE HEALTH CARE: β’ Outpatient care except for initial diagnostic workup of systemic JRA disease and complications for all subtypes β’ Patients require regular (every 4 months in young patients with pauciarticular disease) ophthalmic exams to uncover asymptomatic eye disease, at least for the first 3 years GENERAL MEASURES: Physical therapy including daily home exercise program required for joints with limited motion; moist heat, sleeping bag or electric blanket to relieve morning stiffness SURGICAL MEASURES: Total hip replacement for severe disease may be needed DRUG(S) OF CHOICE * FIRST LINE: . Nonsteroidal anti-infl ammatory medications (NSAIDs) adequate in approximately 50% of patients. Average of 2-3 trials needed to determine most effective drug for an individual patient; adequate duration of trial for given NSAID 4-6 weeks (if no adverse reaction). Drugs for children include: - Ibuprofen (Motrin, Advil, Nuprin) 30-50 mg/kg/d (usual dose is 40 mg/kg/d) - Naproxen (Naprosyn, Aleve) 10-20 mg/kg/d - Tolmetin sodium 15-30 mg/kg/d - Cox-2 inhibitors * SECOND LINE: . 30-40% of patients ultimately require addition of disease-modifying antirheumatic drug (DMARD) e.g., antimalarials, sulfasalazine, methotrexate . Other agents - corticosteroids for serious cardiac involvement or unresponsive uveitis; immune globulin IV, etanercept (Enbrel), or cyclosporine (Neoral) in selected patients PATIENT MONITORING: β’ Patients on NSAIDs - CBC, urinalysis, periodically β’ Patients on aspirin and/or other salicylates - transaminase and salicylate levels, weekly for fi rst month, then every 3-4 months β’ Patient on methotrexate - monthly liver function tests, CBC β’ Ophthalmologic monitoring for antimalarials PREVENTION/AVOIDANCE: β’ Avoid salicylate therapy during serious viral illness or following varicella exposure due to possible risk for Reye syndrome POSSIBLE COMPLICATIONS: . Blindness . Band keratopathy . Glaucoma . Short stature . Debilitating joint disease . Patient on NSAIDs . Peptic ulcer . Gastrointestinal hemorrhage . Rashes . CNS reactions . Renal disease . Leukopenia . Patient on DMARDs . Bone marrow suppression . Hepatitis . Renal disease . Dermatitis . Mouth ulcers . Retinal toxicity (antimalarials) - rare EXPECTED COURSE/PROGNOSIS: . 50-60% ultimately remit, but functional ability depends on adequacy of long-term therapy (disease control and maintaining muscle and joint function) . Poorest prognosis in polyarticular patients with positive rheumatoid factor (RF); and in systemic juvenile arthritis
RELATED DISEASE
Not Available Disease
DISEASE
INVESTIGATION
RA FACTOR, ANTI-NUCLEAR ANTIBODY TEST, X-RAY KNEE JOINT A.P. & LAT. VIEW, X-RAY HAND A.P. & OBLIQUE VIEW, X-RAY WRIST JOINT A.P. & LAT. VIEW, COMPLETE BLOOD COUNT, MRI, HLA TYPING
[ARTHRITIS, JUVENILE RHEUMATOID]