Sydenham's chorea, also known as chorea minor and historically and occasionally referred to as St Vitus' dance, is a disorder characterized by rapid, uncoordinated jerking movements primarily affecting the face, hands and feet. Sydenham's chorea is an autoimmune disease that results from childhood infection with Group A beta-haemolytic Streptococcus. It is reported to occur in 20–30% of people with acute rheumatic fever and is one of the major criteria for it, although it sometimes occurs in isolation. The disease occurs typically a few weeks, but up to 6 months, after the acute infection, which may have been a simple sore throat (pharyngitis).
Sydenham's chorea is more common in females than males and most cases affect children between the ages of 5 and 15 years of age. Adult onset of Sydenham's chorea is comparatively rare, and the majority of the adult cases are recurrences following childhood Sydenham's chorea.