Rheumatic fever and rheumatic heart disease
Often recurrent, acute rheumatic fever is a systemic inflammatory disease of childhood that follows a group A beta-hemolytic streptococcal infection. Rheumatic heart disease refers to the cardiac manifestations of rheumatic fever, including pancarditis (myocarditis, pericarditis, and endocarditis) during the early acute phase and chronic valvular disease later.
Long-term antibiotic therapy can minimize recurrence of rheumatic fever, reducing the risk of permanent cardiac damage and eventual valvular deformity. However, severe pancarditis occasionally produces fatal heart failure during the acute phase. Of the patients who survive this complication, about 20% die within 10 years.
Rheumatic fever appears to be a hypersensitivity reaction to a group A beta-hemolytic streptococcal infection, in which antibodies manufactured to combat streptococci react and produce characteristic lesions at specific tissue sites, especially in the heart and joints. About 3% of patients with untreated streptococcal infections develop rheumatic fever.
Although rheumatic fever tends to run in families, this may merely reflect contributing environmental factors. It primarily affects children between ages 6 and 15, usually within 1 to 5 weeks after strep throat or scarlet fever. The disease strikes most often during cool, damp weather in winter and early spring. In the United States, it’s most common in the northern states.
Signs and symptoms
In 95% of patients, rheumatic fever characteristically follows a streptococcal infection that appeared a few days to 6 weeks earlier. A temperature of at least 100.4° F (38° C) occurs.
Most patients complain of migratory joint pain or polyarthritis. Swelling, redness, and signs of effusion usually accompany such pain, which most commonly affects the knees, ankles, elbows, or hips.
Skin lesions and nodules
In 5% of patients (generally those with carditis), rheumatic fever causes skin lesions, such as erythema marginatum. This nonpruritic, macular, transient rash gives rise to red lesions with blanched centers.
Rheumatic fever may also produce firm, movable, nontender, subcutaneous nodules 1/8″ to ¾″ (0.5 to 2 cm) in diameter, usually near tendons or bony prominences of joints (especially the elbows, knuckles, wrists, and knees) and less commonly on the scalp and backs of the hands. These nodules persist for a few days to several weeks and, like erythema marginatum, often accompany carditis.
Later, rheumatic fever may cause transient chorea, which develops up to 6 months after the original streptococcal infection.
Mild chorea may produce hyperirritability, a deterioration in handwriting, or an inability to concentrate. Severe chorea causes purposeless, nonrepetitive, involuntary muscle spasms; poor muscle coordination; and weakness. Chorea always resolves without residual neurologic damage.
The most destructive effect of rheumatic fever is carditis, which develops in up to 50% of patients. It may affect the endocardium, myocardium, pericardium, or the heart valves.