A Primer on Rheumatic Fever and its Complications
Acute rheumatic fever is a complication of streptococcal sore throat, usually in childhood. Every strep throat is a potential case of rheumatic fever, but the probability of this complication, even without treatment, is only one to three in a hundred. The best way to prevent rheumatic fever is to treat the strep throat early and adequately. Most sore throats are caused not by strep but by cold viruses. However, many physicians give an antibiotic anyway for fear of missing a strep infection. Children who have had rheumatic fever are at high risk of recurrence with future strep throats. To protect them against this danger they receive penicillin continuously for the remainder of their childhood.
While rheumatic fever typically causes intense pain in the joints — hence its name — its real danger is to the heart. Inflammation of the heart, carditis, may cause heart failure, which is sometimes fatal, but most children recover and regain normal heart function. However, a residual process continues after recovery from carditis that slowly deforms the valves. The process typically takes years. The most vulnerable valves are the mitral and aortic, both on the left side of the heart. Unlike the attack that started the process, valve deformity is irreversible, leading to the chronic condition known as rheumatic heart disease. The affected valves may fail to open all the way (stenosis) or close tight (insufficiency, regurgitation) or both. Typical murmurs, sounds of abnormal blood flow, allow the physician to identify each of these lesions.
When the valves don’t work properly, the heart has to pump harder with each beat. After many years the heart muscle may first hypertrophy, then fail from the strain. Unlike the heart failure of acute rheumatic fever, that due to valve malfunction is incapable of spontaneous recovery. The only remedy is surgery to repair or replace the diseased valves.
Deformed valves are also vulnerable to infection by bacteria accidentally entering the blood stream. Such an infection, known as bacterial endocarditis (because the valves are extensions of the endocardium, the heart’s inner lining), damages the valves even further. Ultrasound examination may reveal masses of bacteria and inflamed tissue, termed vegetations, on infected valves. To protect against endocarditis, people with rheumatic heart disease receive extra antibiotics for procedures, particularly on oral tissues and teeth, in which bacteria are known to enter the blood stream. Normal valves easily shed these showers of bacteria without sustaining any damage.
Drug allergy, especially to penicillin, complicates the treatment of people who have had rheumatic fever. Other antibiotics must be used in penicillin-allergic patients. Anaphylaxis is the most serious allergic reaction. Among other effects, it constricts the airways and in extreme cases makes breathing impossible.
Common Abbreviations
| ARF | Acute rheumatic fever |
| RHD | Rheumatic heart disease |
| AS, AI (AR) | Aortic stenosis, aortic insufficiency (regurgitation) |
| MS, MI (MR) | Mitral stenosis, mitral insufficiency (regurgitation) |
| (A/S)BE | (Acute/subacute) bacterial endocarditis |