Chorea (disease)

Definition

Also called St. Vitus' dance, Sydenham's chorea is a disorder effecting children and characterized by jerky, uncontrollable movements, either of the face or of the arms and legs.

Description

Sydenham's chorea is a disorder that occurs in children and is associated with rheumatic fever. Rheumatic fever is an acute infectious disease caused by certain types of streptococci bacteria. It usually starts with strep throat or tonsillitis. These types of streptococci are able to cause disease throughout the body. The most serious damage caused by rheumatic fever is to the valves in the heart. At one time, rheumatic fever was the most common cause of damaged heart valves, and it still is in most developing countries around the world. Rheumatic fever and rheumatic heart disease are still present in the industrialized countries, but the incidence has dropped substantially.

Rheumatic fever may appear in several different forms. Sydenham's chorea is one of five "major criteria" for the diagnosis of rheumatic fever. There are also four "minor criteria" and two types of laboratory tests associated with the disease. The "Jones criteria" define the diagnosis. They require laboratory evidence of a streptococcal infection plus two or more of the criteria. The laboratory evidence may be identification of streptococci from a sore throat or antibodies to streptococcus in the blood. The most common criteria are arthritis and heart disease, occurring in half to three-quarters of the patients. Sydenham's chorea, characteristic nodules under the skin, and a specific type of skin rash occur only 10% of the time.

Causes & symptoms

The cause is only certain types of streptococci, called "Lancefield Group A beta-hemolytic." These particular germs seem to be able to create an immune response that attacks the body's own tissues along with the germs. Those tissues are joints, heart valves, skin, and brain.

Many patients suffer from strep throat, just before developing this new set of symptoms. They may also have joint pains without swelling, a condition known as arthralgia. Sydenham's chorea will appear as uncontrollable twitching or jerking of any part of the body that is worse when trying to repress it but disappears with sleep.

Diagnosis

Because rheumatic fever is such a damaging disease, a complete evaluation should be done whenever it is suspected. This includes cultures for streptococci, blood tests, and usually an electrocardiogram (heartbeat mapping to detect abnormalities).

Treatment

Suspected streptococcus infections must be treated. All the other manifestations of rheumatic fever, including Sydenham's chorea and excluding heart valve damage, remit with the acute disease and do not require treatment. Sydenham's chorea generally lasts for several months.

Prognosis

Syndenham's chorea clears up without complications when the rheumatic fever is treated. The heart valve damage associated with rheumatic fever may lead to heart trouble and require a surgical valve repair or replacement.

Prevention

All strep throats should be treated with a full 10 days of antibiotics (penicillin or erythromycin). Treatment may best be delayed a day or two to allow the body to build up its own antibodies. In addition, for those who have had an episode of rheumatic fever or have damaged heart valves from any other cause, prophylactic antibiotics should be continued to prevent recurrence.

It is possible to eradicate dangerous streptococcus from a community by culturing everyone's throat and treating everyone who tests positive. This is worth doing wherever a case of rheumatic fever appears, but it is expensive and requires many resources.

Key Terms

Arthralgia

Joint pain.

Electrocardiogram

Mapping the electrical activity of the heart.

Rheumatic fever

Chiefly childhood disease marked by fever, inflammation, joint pain, and Syndenham's chorea. It is often recurrent and can lead to heart valve damage.

Tonsillitis

Inflammation of the tonsils, which are in the back of the throat.

Further Reading

For Your Information

Books

• Bisno, Alan L. "Rheumatic Fever." In Cecil Textbook of Medicine, edited by J. Claude Bennett and Fred Plum. Philadelphia: W. B. Saunders, 1996.
• Kaplan, Edward L. "Rheumatic Fever." In Harrison's Principles of Internal Medicine, edited by Kurt Isselbacher, et al. New York: McGraw-Hill, 1998.
• Todd, James. "Streptococcal Infections." In Nelson Textbook of Pediatrics, edited by Waldo E. Nelson, et al. Philadelphia: W. B. Saunders, 1996.

Gale Encyclopedia of Medicine. Gale Research, 1999.