12th March 2024

Pathophysiology

Rheumatic fever is a multi-systemic inflammatory reaction instigated by a preceding streptococcal group A infection which was improperly or inadequately treated. The streptococcal infection typically occurs around two to three weeks prior to this syndrome. Principal organs involved include the heart, joints and skin. 

If left untreated, up to half of patients progress to chronic rheumatic heart disease, which predisposes the individual to arrhythmias, stroke and infective endocarditis. 

In developing countries, rheumatic fever continues to remain endemic and causes significant mortality and morbidity. In these nations, rheumatic heart disease is the leading cause of cardiovascular death in people aged 50 or less.  

Streptococcal pharyngitis is a relatively common infection with highest incidence between the ages of 5 to 15 years. When untreated, Group A streptococcus causes a pathological immune response. Streptococcal antibodies cross-react against myocardial tissue, synovial tissue and parts of the central nervous system. Cardiac valve involvement is caused by monoclonal antibodies initiating lymphocyte infiltration of the endothelium, further propagating the inflammatory response.