What are the diagnostic criteria and treatment for rheumatic fever?

Rheumatic Fever Diagnosis

Diagnose acute rheumatic fever using the 2015 revised Jones Criteria, which requires documented evidence of preceding Group A Streptococcal infection PLUS either 2 major manifestations OR 1 major plus 2 minor manifestations, with different thresholds for low-risk versus moderate-to-high-risk populations. 1, 2

Diagnostic Framework

The diagnosis is fundamentally clinical and stratified by population risk 1, 2:

• Low-risk populations: ARF incidence ≤2 per 100,000 school-aged children or rheumatic heart disease prevalence ≤1 per 1000 population 1
• Moderate-to-high-risk populations: All other regions, including most developing countries 1, 3

Major Criteria (Population-Specific)

Low-Risk Populations 1, 2:

• Carditis (clinical and/or subclinical detected by echocardiography)
• Polyarthritis only (not monoarthritis)
• Chorea
• Erythema marginatum
• Subcutaneous nodules

Moderate-to-High-Risk Populations 1, 2, 4:

• Carditis (clinical and/or subclinical)
• Monoarthritis OR polyarthritis (expanded from low-risk)
• Polyarthralgia (after excluding other causes—this is a critical 2015 addition)
• Chorea
• Erythema marginatum
• Subcutaneous nodules

Minor Criteria (Population-Specific)

Low-Risk Populations 1, 2:

• Polyarthralgia
• Fever ≥38.5°C
• ESR ≥60 mm/h and/or CRP ≥3.0 mg/dL
• Prolonged PR interval (unless carditis is already a major criterion)

Moderate-to-High-Risk Populations 1, 2, 4:

• Monoarthralgia (lower threshold than low-risk)
• Fever ≥38.0°C (lower threshold)
• ESR ≥30 mm/h and/or CRP ≥3.0 mg/dL (lower threshold)
• Prolonged PR interval (unless carditis is already a major criterion)

Essential Diagnostic Testing

Mandatory Tests 2, 5:

• Evidence of preceding GAS infection (required except in rare cases of isolated chorea or indolent carditis): positive throat culture, elevated or rising anti-streptolysin O titer, or other streptococcal antibody tests 5, 6
• Standard echocardiography with Doppler in ALL suspected cases, regardless of auscultation findings 2
• ECG to assess for PR prolongation 2

Echocardiographic Criteria for Pathological Valvulitis 1, 4:

Mitral regurgitation:

• Jet visible in 2 planes
• Length >1 cm
• Holosystolic
• Peak velocity >2.5 m/s 4

Aortic regurgitation:

• Jet visible in 2 planes
• Holodiastolic
• Peak velocity >2.5 m/s 4

Diagnostic Algorithm for Initial Attack

1. Document GAS infection (throat culture or elevated streptococcal antibodies) 5, 6
2. Perform echocardiography with Doppler on all suspected cases—subclinical carditis is now a major criterion and cardiac auscultation alone has very low sensitivity 2
3. Apply population-specific Jones Criteria:
   • Low-risk: 2 major OR 1 major + 2 minor 1
   • Moderate-to-high-risk: Same requirements but with expanded criteria 1

Recurrent Attacks 1, 2, 4:

In patients with prior rheumatic fever or established rheumatic heart disease, diagnosis requires documented GAS infection PLUS:

• 2 major manifestations, OR
• 1 major + 2 minor manifestations, OR
• 3 minor manifestations (new lower threshold for recurrences) 2, 4

Critical Pitfalls to Avoid

• Never rely on cardiac auscultation alone—it has very low sensitivity for detecting carditis; echocardiography is mandatory 2
• Do not diagnose ARF without documented streptococcal infection except in rare cases of isolated chorea or indolent carditis 2, 5
• Distinguish physiological from pathological valve regurgitation—use the specific echocardiographic criteria above; signals that are not holosystolic and peak velocity <3.0 m/s are more likely physiological 1
• Exclude other diagnoses when using monoarthritis or polyarthralgia as major criteria in moderate-to-high-risk populations—consider Lyme disease, serum sickness, drug reactions, post-streptococcal reactive arthritis, endocarditis, and systemic lupus erythematosus 1, 5, 3
• Joint manifestations can only count in either major OR minor categories, never both in the same patient 1

"Possible" Rheumatic Fever 2, 4:

When diagnostic uncertainty exists but clinical suspicion is high:

• Initiate secondary antibiotic prophylaxis for 12 months 2, 4
• Perform detailed clinical history, physical examination, and control echocardiogram at 12 months 4
• Reassess whether to continue or discontinue prophylaxis based on findings 2, 3

Treatment Considerations

The 2015 revision fundamentally changed diagnosis by:

• Incorporating subclinical carditis detected by echocardiography as a major criterion 1, 2
• Stratifying populations by risk with different diagnostic thresholds 1
• Expanding joint manifestations in moderate-to-high-risk populations to include monoarthritis and polyarthralgia as major criteria 1, 3

These changes significantly increase diagnostic sensitivity, particularly in endemic regions where rheumatic fever remains a major cause of acquired heart disease in children 5, 7.