To describe the epidemiology and clinical features of Sydenham's chorea in
the Aboriginal population of northern Australia a review was conducted of 1
58 episodes in 108 people: 106 were Aborigines, 79 were female, and the mea
n age was 10.9 years at first episode. Chorea occurred in 28% of cases of a
cute rheumatic fever, carditis occurred in 25% of episodes of chorea, and a
rthritis in 8%. Patients with carditis or arthritis tended to have raised a
cute phase reactants and streptococcal serology. Two episodes lasted at lea
st 30 months. Mean time to first recurrence of chorea was 2.1 years compare
d with 1.2 years to second recurrence. Established rheumatic heart disease
developed in 58% of cases and was more likely in those presenting with acut
e carditis, although most people who developed rheumatic heart disease did
not have evidence of acute carditis with chorea. Differences in the pattern
s of chorea and other manifestations of acute rheumatic fever in different
populations may hold clues to its pathogenesis. Long term adherence to seco
ndary prophylaxis is crucial following all episodes of acute rheumatic feve
r, including chorea, to prevent recurrence.