An illness that follows an upper respiratory infection with the group A streptococcus (Streptococcus pyogenes) and is characterized by inflammation of the joints (arthritis) and the heart (carditis). Arthritis typically involves multiple joints and may migrate from one joint to another. The carditis may involve the outer lining of the heart (pericarditis), the heart muscle itself (myocarditis), or the inner lining of the heart (endocarditis). A minority of affected individuals also develop a rash (erythema marginatum), nodules under the skin, or Sydenham's chorea (a neurologic disorder characterized by involuntary, uncoordinated movements of the legs, arms, and face). These clinical manifestations may occur singly or in combination, and although most disappear completely, damage to heart valves may be permanent and progressive, leading to severe disability or death from rheumatic heart disease years after the initial attack.