The valves may become thickened with scar tissue, so that the amount of blood that can flow through the heart is restricted. Until the introduction of antibiotics and steroids, the chief medications were aspirin and other salicylates. Penicillin is prescribed if there is evidence of an ongoing streptococcal infection or the chance of exposure to streptococcal infection. Prednisone may be prescribed to reduce the pain and swelling in the joints, but its effect on the ultimate course of the disease is controversial. If pain is severe, analgesic drugs may be given.
Bed rest is an important part of the treatment, particularly if the disease has caused heart damage.
Depending upon the severity of the disease, the patient may be kept in bed for months, and prolonged convalescence may be needed. In the acute phase of rheumatic fever rest is most important to reduce the work load of the heart. The patient should be made as comfortable as possible and disturbed only when necessary. The care should be planned so that long periods of complete rest are possible. Proper positioning with adequate support of the limbs and maintenance of good body alignment is essential to rest and the prevention of complications.