Sydenham chorea and investigations in acute rheumatic fever
THE CONTEXT
The passage continues the description of Sydenham chorea and outlines investigations for systemic illness, preceding streptococcal infection and carditis in acute rheumatic fever.
Sydenham chorea: features and outcome
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Sydenham chorea occurs in up to one-third of cases and is more common in females.
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Emotional lability may appear first, followed by purposeless, involuntary choreiform movements of the hands, feet or face.
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Speech may be explosive and halting.
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Spontaneous recovery usually occurs within a few months, but approximately one-quarter of affected patients subsequently develop chronic rheumatic valve disease.
Evidence of systemic illness and preceding infection
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Leucocytosis and raised erythrocyte sedimentation rate and C-reactive protein provide evidence of systemic illness.
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Throat swab culture may identify group A β-haemolytic streptococci; cultures may also be obtained from family members and contacts.
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Antistreptolysin O antibody evidence includes rising titres or levels above 200 U in adults or 300 U in children.
Evidence of carditis
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Chest X-ray may show cardiomegaly and pulmonary congestion.
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Electrocardiography may show first-degree and, rarely, second-degree atrioventricular block, features of pericarditis, T-wave inversion and reduced QRS voltages.
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Echocardiography may demonstrate cardiac dilatation and valve abnormalities.