Understanding Acute Rheumatic Fever: Causes and Symptoms

Acute rheumatic fever (ARF) is an autoimmune sequela of untreated/undertreated Group A Streptococcal (GAS) pharyngitis.

Pathogenesis

1. GAS infection (strep throat, scarlet fever)
2. Antibodies against M-protein cross-react with host tissues (molecular mimicry)
3. Inflammation in heart (carditis), joints (polyarthritis), CNS (Sydenham chorea), skin (erythema marginatum, subcutaneous nodules)

Jones Criteria (Diagnosis)

Major: Carditis, polyarthritis, chorea, erythema marginatum, subcutaneous nodules.
Minor: Fever, arthralgia, elevated acute-phase reactants, prolonged PR interval.
Requires 2 major or 1 major + 2 minor + evidence of antecedent GAS.

Prevention

Penicillin (or alternative) for GAS pharyngitis within 9 days prevents ARF. Secondary prophylaxis prevents recurrence.