Ineffective endocarditis and rheumatic fever Flashcards
What is rheumatic fever?
- A multisystem disease which occurs after a group A streptococcal infection
- Affects heart, skin, joints and central nervous system
Describe the aetiopathogenesis of rheumatic fever.
Occurs after Group A, beta haemolytic streptococcal infection.
2-6 week layent period before onset of rheumatic fever.
What are the risk factors for rheumatic fever?
- Patients from low socio-economic groups
- Overcrowded conditions
- HLA DR4 positive
How does rheumatic fever occur?
Occurs after repeated oropharyngeal streptococcal infections causing an exaggerated B lymphocyte response.
Streptococcal antigens cross react with connective tissue
What might people with rheumatic fever develop?
- Vasculitis affecting the connective tissue (inflammation of vessel walls)
- Aschoff’s body, consisting of an aggregate of large cells with polymorphs & basophils around a vascular fibrinoid core
- Pancarditis with the endocardium being the most severely involved (inflammation of all walls of the heart)
Chronic rheumatic fever may develop in 50% of patients with acute rheumatic fever
1% mortality in patients’ with carditis
How do you make a diagnosis of rheumatic fever?
-Duckett-Jones criteria
-Presence of 2 major & 1 minor criteria indicates high probability of rheumatic fever
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What is the prevalence of polyarthritis after the strep sore throat & what does it affect?
Polyarthritis occurs in 80-90% of patients but the arthritis is migratory & lasts for 4-6 weeks
It mainly affects the large joints such as the hip, knee, ankle, elbow & shoulder
The pain may last for a week in any particular joint
Describe carditis in rheumatic fever. (MAJOR)
occurs in 40-50% of patients
Happens 2 weeks after polyarthiritis and involves all the cardiac tissue
Lasts 3-6 months
Clinical features vary, it may be asymptomatic or may be present with congestive cardiac failure.
Asymptomatic cases are usually only recognised after the presentation of other clinical signs or cardiomegaly on the chest X-Ray
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Describe pericarditis in rheumatic fever. (MAJOR)
Occurs in 5-10% of patients
Inflammation of cardiac pericardium
Presents with fluid in the pericardial space and may give rise to an intermittent pericardial rub
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Describe myocarditis in rheumatic fever. (MAJOR)
- All of myocardium may be involved
- Patients present with left ventricular failure which may lead to right ventricular failure and subsequent congestive cardiac failure
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Describe endocarditis in rheumatic fever. (MAJOR)
- inflammation of inner lining of the heart chambers
-Mitral valve is most commonly affected
-May occur alone or in association with the aortic valve failure
-Mitral + aortic valve disease = fulminant (associated with high mortality rate)
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Describe chorea in rheumatic fever. (MAJOR)
- Late symptom, May occur 4 to 6 months after the other features of rheumatic fever
- Involuntary movement of face and limbs
-Disappears during sleep
-occurs in 10% of patients
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Describe subcutaneous nodules in rheumatic fever. (MAJOR)
- Subcutaneous nodules = rare
-Small (up to 0.5cm) are non- tender, mobile and firm - Occur over bony prominence
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Describe erythema nodusum in rheumatic fever. (MAJOR)
- May also occur over the shins
- Larger and more painful than subcutaneous nodules
-Deep pink/Red
-Nodules are tender on palpating
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Describe erythema marginatum in rheumatic fever:
- Occurs in 65% of patients
- Painless and non-pruritic rash (not itchy)
-It has a serpinginous edge with a fading centre and spreads over the trunk and limbs