The diagnosis of Acute Rheumatic Fever (ARF) is based on the Jones Criteria, revised by the American Heart Association (AHA). The criteria are divided into major and minor manifestations, supported by evidence of a preceding Group A Streptococcal infection.
1. Jones Criteria (Revised)
A. Major Criteria
- Carditis
- Inflammation of the heart, affecting any layer (endocarditis, myocarditis, or pericarditis).
- Signs include murmur, pericardial rub, heart failure, or cardiomegaly.
- Polyarthritis
- Migratory arthritis predominantly affecting large joints (knees, ankles, elbows, and wrists).
- Chorea (Sydenham chorea)
- Involuntary, irregular, and non-repetitive movements, often with emotional instability.
- Erythema Marginatum
- Non-pruritic rash with a red, serpiginous border and central clearing, mostly on the trunk and proximal limbs.
- Subcutaneous Nodules
- Small, firm, painless lumps over bony prominences or extensor tendons.
B. Minor Criteria
- Clinical Findings
- Arthralgia (joint pain without swelling).
- Laboratory Findings
- Fever (≥38.5°C/101.3°F for high-risk populations, ≥38°C/100.4°F for others).
- Elevated acute-phase reactants (e.g., erythrocyte sedimentation rate [ESR] or C-reactive protein [CRP]).
- Electrocardiographic Finding
- Prolonged PR interval (first-degree heart block), unless attributable to another cause.
C. Evidence of Preceding Group A Streptococcal (GAS) Infection
- Positive throat culture or rapid antigen test for GAS.
- Elevated or rising anti-streptolysin O (ASO) or anti-DNase B titers.
- Recent scarlet fever history.
2. Diagnostic Guidelines
To confirm ARF, the following combinations are required:
- Two major criteria OR
- One major and two minor criteria
AND
- Supporting evidence of preceding Group A Streptococcal infection.
3. Risk Stratification Modifications
For high-risk populations (e.g., developing countries with high incidence of ARF):
- Polyarthritis may be replaced by monoarthritis or polyarthralgia.
- Fever threshold lowered to ≥38°C.
- A lower cutoff for ESR and CRP may be applied.
4. Management
Early recognition and treatment of ARF are critical to prevent Rheumatic Heart Disease (RHD). Key interventions include:
- Antibiotics to eradicate GAS.
- Anti-inflammatory treatment (e.g., aspirin, corticosteroids).
- Secondary prophylaxis with long-term penicillin to prevent recurrence.
