Acute rheumatic fever

Background

• Primarily affects school age children 2-6 weeks after Group A streptococcal pharyngitis
  • Is not associated with impetigo
• Connective tissue of heart, joints, CNS, subcutaneous tissues are targeted by immune reaction

Clinical Features

• Polyarthritis
  • Most common symptom (~75%)
  • Aseptic arthritis with effusions
  • Lasts up to 2 weeks
  • Migratory, fleeting polyarticular arthritis primarily affecting large joints
• Carditis (33%)
  • Most serious complication and second most common
  • Tachycardia out of proportion to the degree of fever is common; its absence makes the diagnosis of myocarditis unlikely
  • New murmur, pericardial rub, CHF
• Sydenham's chorea (10%)
  • May appear months following strep infection, may be sole manifestation of RF
  • Movements extinguish during sleep
• Erythema marginatum (< 10%)
  • Persists only for several days
  • Usually coexists with presence of carditis in some form
  • Nonpruritic rash, located on trunk and proximal limbs, never on face
• Nodules(< 10%)
  • Located on extensor surfaces of wrists, elbows, knees

Differential Diagnosis

• Scarlet fever
• Kawasaki Disease
• Viral or other forms of cardiomyopathy
• Leukemia
• Vasculitis (HSP, drug reaction)

Pediatric hip pain

• 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

Polyarthritis

Algorithm for Polyarticular arthralgia

• Fibromyalgia
• Juvenile idiopathic arthritis
• Lyme disease
• Osteoarthritis
• Psoriatic arthritis
• Reactive poststreptococcal arthritis
• Rheumatoid arthritis
• Rheumatic fever
• Serum sickness
• Systemic lupus erythematosus
• Serum sickness–like reactions
• Viral arthritis

Evaluation

Work-Up

• CBC
• ECG
• CXR
• ESR, CRP
• ASO (Antistreptolysin O) titer Eleveted 1week to 1 month after GAS infection
• Anti-DNase B titer is elevated longer than ASO and may be useful for patient presenting later than 2-4 months or with a negative ASO
• ECG - Looking for prolonged PR or other AV block
• CXR
• Echocardiogram

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 (CASES)
  • Carditis (new or changing murmur, cardiomegaly, CHF, pericarditis)
  • Arthritis, migratory polyarthritis (typically affects knees, ankles, elbows, wrists)
  • Sydenham's Chorea (abrupt, involuntary, purposeless movements)
  • Erythema marginatum (non-pruritic, trunk/extremities, with facial sparing)
  • Subcutaneous nodules (painless, firm, usually over bones/tendons)
• 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

Management

• Penicillin - Indicated for all with rheumatic fever even if culture for strep is negative
  • Penicillin G 600K units IM if <27 kg, 1.2 million units IM if >27 kg
  • Penicillin V PO x10d
• For those who are penicillin allergic
  • Narrow spectrim cephalosporins such as cephalexin 20mg/kg/dose BID x10d
  • Clindamycin 7mg/kg/dose TID (max of 300mg/dose) PO x10d
  • Azithromycin 12mg/kg once (500mg max) and then 6mg/kg (250mg max) daily for the next 4 days
• Prophylaxis
  • Penicillin G IM x1 month

Category	Duration
Rheumatic fever without carditis	5 years or until age 21 years, whichever is longer
Rheumatic fever with carditis but without residual heart disease (no valvular disease)	10 years or well into adulthood, whichever is longer
Rheumatic fever with carditis and residual heart disease (persistent valvular disease)	10 years since last episode and at least until age 40 years; most commonly lifelong

• Arthritis
  • High-dose aspirin therapy (50-100mg/kg/day) has historically been first line
  • Naproxen may be just as effective with less frequent dosing and fewer side effects
• Carditis
  • Aspirin is primary treatment
  • Prednisone 1-2mg/kg/day has no benefit over aspirin in proventing heart disease at one year
    • Some consider for severe carditis
  • Standard medical therapy for Congestive Heart Failure
• Chorea - It is self limited but several agents had been described as effective, although not well studied
  • Haloperidol 0.01-0.03mg/kg/day in four divided doses
  • Valproate
  • Diazepam
  • Phenobarbital
  • Chlorpromazine

Complications

• Rheumatic Heart Disease
  • Worldwide most common cause of valvular heart disease
  • Occurs usually 10+ years after RF
  • Mitral valve is most commonly affected, followed by aortic valve
  • 50% of those with carditis during acute RF
• Jaccoud arthropathy
  • Painless deformities without joint inflammation

Disposition

• Admit

External Links

• emDocs - An Understated Myth? Strep Throat & Rheumatic Fever
• CDC guidelines for GAS Disease

See Also

• Sydenham's chorea