In other cases, it appears that only the joints are affected. Not everyone with a strep throat gets rheumatic fever because it may be only certain strains of the strep bacteria that cause it in people who may be predisposed to have a reaction to it. Some people have the strep bacteria in their throats all the time, called colonization, and do not get rheumatic fever. The pain in the joints is usually very severe so that even touching the joints lightly is intolerable. The joint problems eventually disappear with no long term damage.
Some people develop uncontrollable twitches or movements of muscles in the face, arms, and legs.
The medical name for these movements is chorea, but it is commonly known as St. Vitus' dance. The twitches and joint pains usually disappear after a few weeks without any long-term damage. When the heart muscle is involved, the problem becomes more serious. The heart muscle cells may be weakened due to inflammation, interfering with the heart's ability to pump. The inflammation also affects the heart valves, but this may not be evident until years later.