Rheumatic fever is an inflammatory disease triggered by infections with Lancefield group A streptococci (S. pyogenes). It is an inappropriate immune response to streptococcal antigens and may affect the heart, joints and central nervous system.
Age: Usually occurs in children.
Region: Rare in Europe and North America. Endemic in Asia, Africa and South America
Triggered by an immune-mediated, delayed response to infection from Strep. pyogenes.
Streptococcal antigens can cross-react with cardiac myosin and sarcolemmal membrane protein. Thus, antibodies are produced that can target the endocardium, myocardium and pericardium, as well as skin and joints.
Histology: Fibrinoid degeneration in collagen. Aschoff nodules, multinucleated giant cells surrounded by macrophages and T cells, may be present in cardiac tissue.
Multisystem disorder that present 2-3 weeks after an episode of Streptococcal pyogenes with symptoms including:
- Joint pain (75% of presentations)
Jones criteria can be used to aid in the clinical diagnosis of rheumatic fever. Rheumatic fever can be diagnosed if there is proven streptococcal infection (e.g. ASOT, throat swab, scarlet fever) with either:
- 2 major criteria met
- 1 major and 2 minor criteria met
- Bloods: raised CRP/ESR, leucocytosis
- ECG: 1st degree heart block
- Pericardial effusions
- Cardiac dilation (carditis)
- Valve abnormalities
- Chest x-ray: cardiomegaly, pulmonary congestions
- Antistreptolysin O titre (ASOT) and throat swab cultures.
Bed rest until CRP normalises, which may take weeks to months.
Provide medical therapy in the form of:
- Antibiotics: single dose IM benzylpenicillin
- Aspirin for arthritis
- Steroids for carditis or severe arthritis
- Haloperidol for chorea
- Carditis can lead to pericarditis, myocarditis, endocarditis and valvulitis. These can lead to valvular lesions, particularly mitral stenosis
- Sydenham’s chorea: disorder of movement lasting 3-6 months, producing involuntary movements of the face and limbs
50% of patients with carditis develop chronic rheumatic heart disease. The most common outcome is mitral stenosis, although aortic stenosis and tricuspid stenosis may occur. Stenosed valves may become regurgitant later in life.