Final answer:
Rheumatic fever is an autoimmune disease that can follow untreated streptococcal infections, characterized by carditis, arthritis, and a history of a preceding streptococcal infection. Damage to the heart valves from carditis is a serious complication, and prevention is crucial through early treatment of streptococcal pharyngitis.
Step-by-step explanation:
Three major criteria for diagnosing rheumatic fever include:
- Carditis: Inflammation of the heart that can lead to valvular disorders and a characteristic heart murmur.
- Joint pain and swelling: Symptomatic of arthritis, a reversible damage to joints caused by rheumatic fever.
- Evidence of a preceding streptococcal infection: Shown through elevated acute-phase proteins or a history of pharyngitis caused by S. pyogenes.
Rheumatic fever typically follows an untreated or inadequately treated streptococcal pharyngitis. This autoimmune response, mediated by molecular mimicry, causes the antibodies produced against streptococcal bacteria to cross-react with cardiac, neuronal, and synovial tissues.
One of the most serious consequences is carditis, which can result in irreversible damage to heart valves. Prevention and early treatment of the initial streptococcal infection are pivotal in reducing the risk of developing rheumatic fever and its complications.