Acute rheumatic fever

Background

• Primarily affects school age children 2-6wk after strep pharyngitis
• Connective tissue of heart, joints, CNS, subq tissues are targeted by immune reaction

Diagnosis

Modified Jones Criteria (1992) for Acute Rheumatic Fever

REQUIRE: 2 major or 1 major and 2 minor criteria and evidence of previous GAS pharyngitis.

• Major diagnostic criteria
  • Carditis
    • New or changing murmur, cardiomegaly, CHF, pericarditis
  • Migratory polyarthritis
  • Chorea
  • Subcutaneous nodules
  • Erythema marginatum
• Minor diagnostic criteria
  • Fever
  • Arthralgia
  • History of previous attack of rheumatic fever
  • Prolonged PR interval
  • Elevated ESR, CRP
• Evidence of preceding streptococcal infection
  • Increased ASO or other strep ab
  • Positive throat culture for Group A strep
  • Positive rapid GAS
  • Recent scarlet fever

Symptoms

• Polyarthritis
  • Most common symptom (75%)
  • Migratory, fleeting polyarticular arthritis primarily affecting large joints
• Carditis (33%)
  • Most serious complication and second most common
    • New murmur, pericardial rub, CHF
• Chorea (10%)
  • May appear months following strep infection, may be sole manifestation of RF
• Erythema marginatum
  • Persists only for several days
  • Usually coexists with presence of carditis in some form
  • Nonpruritic, located on trunk and proximal limbs, never on face
• Nodules
  • Located on extensor surfaces of wrists, elbows, knees

Differential Diagnosis

• JIA
• Septic Arthritis
• Kawasaki Disease
• Viral or other forms of cardiomyopathy
• Leukemia
• Vasculitis (HSP, drug reaction)
• Hip Pain (Peds)

Pediatric limp

Hip Related

• Acute rheumatic fever
• Developmental dysplasia of hip
• Femur fracture
• Juvenile idiopathic arthritis
• Legg-Calve-Perthes disease
• Septic arthritis of the hip (peds)
  • Lyme disease arthritis
• Slipped capital femoral epiphysis
• Transient (toxic) synovitis
• Osteosarcoma

Other Causes of Limping

• Developmental dysplasia
• Fracture
  • Toddler's fracture
  • Tillaux fracture, adolescent
• Neoplasm:
  • Leukemia
  • Ewings
  • Osteogenic sarcoma
  • Metastatic neuroblastoma
• Osteomyelitis
• Myositis
• Other:
  • Appendicitis
  • Meningitis
  • Epidural abscess (spinal)

Work-Up

• CBC
• ECG
• CXR
• ESR, CRP

Treatment

• Penicillin
  • Indicated for all pts w/ rheumatic fever even if cx for strep is negative
  • 600K units IM if <27 kg
  • 1.2 million units IM if >27 kg
  • Penicillin V PO x10d
  • Prophylaxis
    • 5yr if no cardiac involvement, lifetime if cardiac involvement
    • Pen G IM q month or oral penicillin daily
  • Erythromycin x10d if pen allergic
• Arthritis
  • High-dose aspirin therapy (75-100 mg/kg/d)
• Carditis
  • Prednisone 1-2mg/kg/d
• Chorea
  • Haloperidol 0.01-0.03 mg/kg/d in four divided doses

Disposition

• Admit for confirmation of diagnosis