Prevention of Recurrent Rheumatic Fever
The initial episode of rheumatic fever can usually be prevented by early treatment of streptococcal pharyngitis.  Prevention of recurrent episodes is critical. Recurrences of rheumatic fever are most common in patients who have had carditis during their initial episode and in children, 20% of whom will have a second episode within 5 years. Recurrences are uncommon after 5 years and in patients over 25 years of age. Prophylaxis is usually discontinued after these times except in groups with a high risk of streptococcal infection - parents or teachers of young children, nurses, military recruits, etc.

A. Penicillin
The preferred method of prophylaxis is with benzathine penicillin G, 1.2 million units intramuscularly every 4 weeks. Oral penicillin (200,000-250,000 units twice daily) is less reliable.

B. Sulfonamides or Erythromycin
If the patient is allergic to penicillin, sulfadiazine (or sulfisoxazole), 1 g daily, or erythromycin, 250 mg orally twice daily, may be substituted.

Prognosis
Initial episodes of rheumatic fever may last months in children and weeks in adults. The immediate mortality rate is 1-2%. Persistent rheumatic carditis with cardiomegaly, heart failure, and pericarditis implies a poor prognosis; 30% of children thus affected die within 10 years after the initial attack. After 10 years, two-thirds of patients will have detectable valvular abnormalities (usually thickened valves with limited mobility), but significant symptomatic valvular heart disease or persistent cardiomyopathy occurs in less than 10% of patients with a single episode. In developing countries, acute rheumatic fever occurs earlier in life, recurs more frequently, and the evolution to chronic valvular disease is both accelerated and more severe.