Sydenhams 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. Sydenhams 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). Sydenhams 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 Sydenhams chorea is comparatively rare, and the majority of the adult cases are recurrences following childhood Sydenhams chorea. Signs and symptoms
Sydenhams chorea is characterized by the abrupt onset (sometimes within a few hours) of neurologic symptoms, classically chorea, which are non-rhythmic, writhing or explosive involuntary movements. Usually all four limbs are affected, but there are cases reported where just one side of the body is affected (hemichorea). Typical chorea includes repeated wrist hyperextension, grimacing, lip pouting. The fingers can move as if playing the piano. There may be tongue fasciculations ("bag of worms") and motor impersistence for example the "milk maid sign" (grip strength fluctuates, as if hand milking), or inability to sustain tongue protrusion or eye closure.
Intramuscular penicillin is given every 2–3 weeks superior to 4 weekly regime, and oral penicillin is also prescribed. Recurrences are sometimes associated with rise in ASO titre or other evidence of new streptococcal infection. There is no obvious clinical parameter that might predict those at risk of recurrence. More likely if failure to remit in initial 6 months, can recur with pregnancy (chorea gravidorum). Higher recurrence rates seen in longest follow up – can recur up to 10 years after the initial episode, so might be underestimated by series with shorter follow up. Recurrence is usually only chorea, even if the original case was associated with rheumatic fever. There are two total reports of heart disease worsening after recurrence of chorea. The Thailand study also had 2 cases where carditis, which had improved after initial diagnosis, came back again. Some suggest that recurrent chorea is a different disease altogether.10% reported long term tremor in one study (10 years follow up). Long term neuropsychiatric difficulties are increasingly recognized (49 studies so far, especially obsessive-compulsive disorder but also attention-deficit hyperactivity disorder, affective disorders, tic disorders, executive function disturbances, psychotic features, and language impairment).Heart involvement improves in about a third of cases (whether silent or not). [PMID 22734303]

Family support
Sydenhams Chorea Association

History
The incidence of acute rheumatic fever and rheumatic heart disease is not declining. Recent figures quote the incidence of Acute Rheumatic Fever as 0.6–0.7/1,000 population in the United States and Japan compared with 15–21/1,000 population in Asia and Africa.