Introduction

First described in 1684 (Comrie, 1922), Sydenham chorea (SC) is now known to be a major manifestation of rheumatic fever (RF) and occurs in 20 to 40% of RF cases. The disorder is still common in some parts of the world, occurring in as many as 1% of children in Australian Aboriginal communities (Carapetis & Currie, 1997), although it is uncommon in non-Aboriginal communities of Australia and in other developed countries. The disorder appears to have recently resurfaced in the United States with increasing numbers of sporadic cases nationwide (Bisno et al., 1988; Kaplan & Markowitz, 1988) and scattered epidemics in regions such as Ohio River valley, and the intermountain region of Utah (Veasy et al., 1987, 1994; Leads from the MMWR, 1998a, b; Hosier et al., 1987). The diagnosis of rheumatic fever requires the presence of two major, or one major and two minor manifestations, as well as evidence of a recent streptococcal infection (Special Writing Group of the Committee on Rheumatic Fever, 1992). SC is an exception to these criteria, because it is known to occur up to 9 months after a streptococcal infection (Berrios et al., 1985), in the absence of any other manifestations of RF. Thus, SC is frequently a diagnosis of exclusion.