Also called St. Vitus' dance, Sydenham's chorea is a disorder of the central nervous system characterized by jerky, uncontrollable movements, either of the face or of the arms and legs. It occurs chiefly in children following an attack of rheumatic fever (an infectious disease caused by certain types of bacteria, usually beginning with a strep throat or tonsillitis).

Sydenham's chorea is rare in the United States today, although it is a common problem throughout the developing world.

Sydenham's chorea appears as uncontrollable twitching or jerking of any part of the body that gets worse if the patient tries to stop the movements, but disappears with sleep. The involuntary jerks are random, and voluntary movements are clumsy. Early signs of the problem include slurred speech and increasingly-poor handwriting.

Treatment includes bed rest and antibiotics; sedation may be needed if the involuntary movements are severe. Sydenham's chorea will go away as the patient recovers, and it doesn't usually require treatment, although it responds to mild sedatives. Typically, it lasts for several months before clearing up; there are no long-term problems associated with the condition.

It can be prevented only if rheumatic fever is prevented, by treating a bacterial infection with a full 10 days of antibiotics (penicillin or erythromycin).