What is Rheumatic Fever
Rheumatic fever is an inflammatory illness that occurs as a delayed autoimmune sequela of group A streptococcal (GAS) pharyngitis, developing 14-21 days after the initial throat infection in genetically susceptible individuals. 1, 2
Pathophysiology and Timing
- Rheumatic fever develops through molecular mimicry following Lancefield group A streptococcus pharyngitis, occurring after a symptom-free interval of 2-4 weeks after the initial infection 2, 3, 4
- The disease is an immunologically mediated inflammatory response that affects multiple organ systems 5, 4
- At least one-third of rheumatic fever cases result from asymptomatic GAS infections, meaning patients never had recognized pharyngitis 2, 6
Clinical Manifestations
The diagnosis requires two major criteria OR one major and two minor criteria, plus evidence of preceding GAS infection 1, 2:
Major Criteria:
- Carditis (most significant for long-term morbidity and mortality) 1, 2
- Polyarthritis 1, 2
- Chorea (Sydenham's chorea) 1, 4
- Subcutaneous nodules 1, 4
- Erythema marginatum 1, 4
Minor Criteria:
- Previous rheumatic fever or rheumatic heart disease 1
- Arthralgia 1
- Fever 1
- Elevated inflammatory markers (ESR, CRP, or leukocytosis) 1
- Prolonged PR interval on ECG 1
Critical Clinical Implications
Rheumatic fever carries significant risk of permanent cardiac damage, with potential for severe rheumatic heart disease and lifelong disability. 2
- Rheumatic heart disease remains the largest global cause of cardiovascular disease in people under 25 years of age 3
- Valvular heart disease may require lifelong prophylaxis and can worsen with recurrent attacks 2
- Individuals who have had one attack of rheumatic fever are at very high risk (substantially elevated) for recurrent attacks after subsequent GAS pharyngitis 1
- Recurrent attacks can worsen the severity of existing rheumatic heart disease or cause new-onset cardiac disease in those who did not develop cardiac manifestations during the first attack 1
Prevention Context
Primary prevention is accomplished by proper identification and adequate antibiotic treatment of GAS pharyngitis before rheumatic fever develops. 1
- During historical epidemics, up to 3% of untreated acute streptococcal pharyngitis was followed by rheumatic fever 1
- Appropriate antibiotic treatment of streptococcal pharyngitis prevents acute rheumatic fever in most cases 1
- However, rheumatic fever can occur even when GAS pharyngitis is treated optimally, highlighting the importance of continuous prophylaxis in those with prior disease 6
Common Pitfall
The most critical pitfall is that rheumatic fever is not an acute infection itself—it is a delayed inflammatory complication that occurs weeks after the initial streptococcal throat infection has resolved. 2, 5 This distinguishes it fundamentally from scarlet fever, which is the acute manifestation of GAS infection with characteristic rash occurring during active infection 2.