10. Rheumatologic Disorders in Children

Overview

  • Presenter: Stephanie Aldret, DO, FAOASM

  • Course: MED 7301 Clinical Medicine

  • Lecture 10: Rheumatological Disorders in Children

Topics Covered

  • Juvenile Idiopathic Arthritis (JIA)

  • Henoch-Schonlein Purpura (HSP)

  • Pediatric and Congenital Systemic Lupus Erythematosus (SLE)

  • Juvenile Dermatomyositis (JDM)

  • Generate differential diagnosis of acute arthritis in children

  • Identify the diagnostic criteria for JIA

  • Compare JIA subtypes based on ILAR system: typical presentation, laboratory findings, prognosis, and complications

  • Treatment modalities for JIA and common pharmacological agents in pediatrics

  • Compare reactive arthritis, transient synovitis, and septic joint clinical presentations

  • Recognize SLE presentation, laboratory findings, and common pediatric SLE morbidities

  • Identify JDM cutaneous manifestations and serious complications

  • Recognize HSP clinical manifestations and complications

Differential Diagnosis of Acute Arthritis in Children

Infection

  • Septic arthritis, osteomyelitis, lyme disease

Orthopedic Conditions

  • Legg-Calve-Perthes, osteochondritis dissecans, slipped capital femoral epiphysis, trauma, hypermobility

Rheumatologic Conditions

  • JIA, hemarthrosis

Other Causes

  • Trauma, vascular malformation, bleeding diathesis, malignancy, transient synovitis

Juvenile Idiopathic Arthritis (JIA)

Definition

  • Not a single disease, a category of chronic idiopathic inflammatory disorders primarily involving joints.

Epidemiology

  • Most common rheumatic disease in childhood (1:1000)

  • Two peaks: 1-3 years and 8-12 years

Diagnostic Criteria

  • Chronic arthritis in ≥1 joint for at least 6 weeks

  • Age <16 years

  • Exclusion of other forms of juvenile arthritis

ILAR Classification and Subtypes

  1. Systemic (5-15%)

  2. Oligoarticular (40-50%)

    • Persistent and Extended

  3. Polyarthritis (20-35%)

    • Rheumatoid Factor Negative and Positive (<10%)

  4. Enthesitis-Associated (5-10%)

  5. Psoriatic Arthritis (5-10%)

Labs and Imaging

  • Elevated inflammatory markers (ESR, CRP)

  • Normal X-rays initially; may show erosions or osteopenia over time

Treatment

  • NSAIDs: Naproxen, meloxicam, ibuprofen, indomethacin

  • DMARDs: Methotrexate (DOC for polyarticular and systemic JIA), hydroxychloroquine, sulfasalazine

  • Biologics: Etanercept, infliximab, adalimumab

  • Corticosteroids: Reserved for severe disease

Systemic Lupus Erythematosus (SLE)

Epidemiology

  • Rare before 9 years, higher incidence in African, Asian, and Hispanic children

  • Female to male ratio 1:1 in children

Clinical Findings

  • Constitutional: fatigue, fever, weight loss

  • Cutaneous: Malar rash, discoid lesions, photosensitivity, vasculitis

  • Musculoskeletal: Arthritis, arthralgia

  • Renal: Glomerulonephritis risk in 50-70%

  • Neurologic: Seizures, mood disorders

Labs and Diagnostic Criteria

  • Requires presence of 4 out of 11 clinical criteria for diagnosis.

Treatment

  • Mild disease: NSAIDs, hydroxychloroquine

  • Moderate/Severe disease: High-dose corticosteroids, cytotoxic therapy

Juvenile Dermatomyositis (JDM)

Clinical Presentation

  • Rash, proximal symmetric muscle weakness

  • Constitutional symptoms: anorexia, fever

Diagnostic Criteria

  • Requires 4 out of 5 specific findings for diagnosis.

Treatments and Complications

  • Treatments: supportive care, physiotherapy, steroids, immunosuppressives

  • Complications: calcinosis, osteoporosis, gastrointestinal perforation

Henoch-Schonlein Purpura (HSP)

Clinical Presentation

  • Palpable purpura, arthritis/arthralgia, abdominal pain

Treatment

  • Supportive care; NSAIDs for arthritis

  • Corticosteroids for renal or GI involvement

Prognosis

  • Self-limiting condition with most cases resolving within 3-4 weeks.