What are the signs of rheumatic fever?

Signs and Symptoms of Rheumatic Fever

Rheumatic fever diagnosis requires evidence of preceding group A streptococcal infection plus either two major criteria or one major and two minor criteria, with major manifestations including carditis, polyarthritis, chorea, erythema marginatum, and subcutaneous nodules. 1

Diagnostic Criteria (2015 Revised Jones Criteria)

Major Criteria

• Carditis: Can be clinical or subclinical (detected only by echocardiography)
  • Clinical signs: New murmurs, tachycardia out of proportion to fever, precordial pain 1
  • Subclinical: Pathological valve regurgitation detected by echocardiography 1, 2
• Polyarthritis: Migratory inflammation affecting large joints with dramatic response to anti-inflammatory medications 1
• Chorea (Sydenham's): Involuntary, purposeless movements, more common in females, often with emotional lability and muscle weakness 1
• Erythema marginatum: Distinctive skin rash 1
• Subcutaneous nodules: Firm, painless nodules over bony prominences 1

Minor Criteria

• Polyarthralgia: Joint pain without objective inflammation 1
• Fever: Elevated temperature 1, 3
• Elevated acute phase reactants 1:
  • ESR: ≥60 mm/hr for low-risk populations; ≥30 mm/hr for moderate/high-risk populations
  • CRP: ≥3.0 mg/dL
• Prolonged PR interval on ECG 1, 3

Evidence of Preceding Group A Streptococcal Infection

• Positive throat culture for group A streptococcus
• Elevated or rising anti-streptolysin O titer 3, 4

Population-Specific Considerations

The 2015 revised Jones criteria introduced different diagnostic thresholds based on population risk 1, 5:

• Low-risk populations: ARF incidence <2 per 100,000 school-aged children or RHD prevalence ≤1 per 1000
• Moderate/high-risk populations: All other populations

Clinical Presentation Timeline

Symptoms typically develop 2-3 weeks following streptococcal pharyngitis 6. The presentation can vary significantly:

• Carditis: May present as new murmurs, heart failure symptoms, or be subclinical
• Joint involvement: Can range from arthralgia to frank polyarthritis
• Chorea: May appear late in the disease course, sometimes weeks after other symptoms have resolved 1

Diagnostic Challenges and Pitfalls

• Echocardiography is now recommended for all patients with suspected rheumatic fever, even without clinical signs of carditis, to detect subclinical carditis 2
• The concept of "exceptions to Jones Criteria" applies to patients with chorea, indolent carditis, and those with previous history of rheumatic fever 3
• Clinical judgment remains important, as strict adherence to criteria may result in underdiagnosis in high-prevalence regions 3
• Differential diagnosis should consider conditions with overlapping features such as Lyme disease, serum sickness, drug reactions, and post-streptococcal reactive arthritis 4

Laboratory Findings

• Leukocytosis (>10,000 white blood cells/mm³)
• Anemia may be present
• Elevated inflammatory markers (ESR, CRP) 1

The diagnosis of rheumatic fever remains primarily clinical, supported by laboratory evidence of recent streptococcal infection. The 2015 revised Jones criteria represent the most current diagnostic framework, with important modifications including the recognition of subclinical carditis and population-specific diagnostic thresholds 1, 5.