168.1 Rheumatic Fever
There is considerable evidence to support the link between group A streptococcus upper respiratory tract infections and acute rheumatic fever and rheumatic heart disease. As many as two thirds of the patients with an acute episode of rheumatic fever have a history of an upper respiratory tract infection several weeks before, and the peak age and seasonal incidence of acute rheumatic fever closely parallel those of group A streptococcal infections. Patients with acute rheumatic fever almost always have serologic evidence of a recent group A streptococcal infection. In addition, their antibody titers are usually considerably higher than those seen in patients with group A streptococcal infections without acute rheumatic fever. Outbreaks of group A streptococcal pharyngitis in closed communities, such as boarding schools or military bases, may be followed by outbreaks of acute rheumatic fever. Finally, antimicrobial therapy that eliminates group A streptococcus from the pharynx also prevents initial episodes of acute rheumatic fever,
and long-term, continuous prophylaxis that prevents group A streptococcal pharyngitis also prevents recurrences of acute rheumatic fever.
Not all of the serotypes of group A streptococcus can cause rheumatic fever. When some strains (e.g., M type 4) were present in a very susceptible rheumatic population, no recurrences of rheumatic fever occurred. In contrast, episodes of pharyngitis with other serotypes prevalent in the same population were associated with frequent recurrences. The concept of rheumatogenicity is further supported by the observation that although serotypes of group A streptococcus frequently associated with skin infection are often isolated from the upper respiratory tract, they rarely cause recurrences of rheumatic fever in individuals with a previous history of rheumatic fever. In addition, certain serotypes of group A streptococcus (e.g., M types 1, 3, 5, 6, 18, 24) are more frequently isolated from patients with acute rheumatic fever than are other serotypes.
In some developing areas of the world, the annual incidence of acute rheumatic fever is currently as high as 282/100,000 population. Worldwide, rheumatic heart disease remains the most common form of acquired heart disease in all age groups, accounting for as much as 50% of all cardiovascular disease and as much as 50% of all cardiac admissions in many developing countries. However, striking differences are evident in the incidence of acute rheumatic fever and rheumatic heart disease among different ethnic groups within the same country; many, but not all, of these differences appear to be related to differences in socioeconomic status.
In the United States, at the beginning of the 20th century, acute rheumatic fever was the leading cause of death among children and adolescents, with annual incidence rates of 100–200/100,000 population. In addition, rheumatic heart disease was the leading cause of heart disease among adults <40 yr of age. At that time, as many as one fourth of the hospital beds in the United States were occupied by patients suffering from acute rheumatic fever or its complications. By the 1940s, the annual incidence of acute rheumatic fever had decreased to 50/100,000, and over the next 4 decades, the decline in incidence accelerated rapidly. By the early 1980s, the annual incidence in some areas of the United States was as low as 0.5/100,000 population. This sharp decline in the incidence of acute rheumatic fever has been observed in other industrialized countries as well.
The explanation for this dramatic decline in the incidence of acute rheumatic fever and rheumatic heart disease in the United States and other industrialized countries is not clear. Historically, acute rheumatic fever has been associated with poverty, particularly in urban areas. Much of the decline in the incidence of acute rheumatic fever in industrialized countries during the preantibiotic era can probably be attributed to improvements in living conditions. A number of studies have suggested that, of the various manifestations of poverty, crowding, which contributes to the spread of group A streptococcal infections, is the one most closely associated with the incidence of acute rheumatic fever. The decline in incidence of acute rheumatic fever in industrialized countries over the past 4 decades has also been attributable in large measure to the greater availability of medical care and to the widespread use of antibiotics. Antibiotic therapy of group A streptococcal pharyngitis has been important in preventing initial attacks and, particularly, recurrences of the disease. In addition, the decline can be attributed, at least in part, to a shift in the prevalent strains of group A streptococcus from rheumatogenic to nonrheumatogenic strains.
A dramatic outbreak of acute rheumatic fever in the Salt Lake City area began in early 1985, and 198 cases were reported by the end of 1989. Other outbreaks were reported between 1984 and 1988 in Columbus and Akron, OH; Pittsburgh, PA; Nashville and Memphis, TN; New York City, NY; Kansas City, MO; Dallas, TX; and among recruits at the San Diego Naval Training Center in California and at the Fort Leonard Wood Army Training Base in Missouri. Evidence suggests that this resurgence of acute rheumatic fever was focal and not nationwide.
Certain rheumatogenic serotypes (e.g., types 1, 3, 5, 6, and 18) that were isolated infrequently during the 1970s and early 1980s dramatically reappeared during these focal outbreaks. The appearance of these rheumatogenic strains in selected communities was probably a major factor in these outbreaks of acute rheumatic fever. Another property of group A streptococcus that has been associated with rheumatogenicity is the formation of highly mucoid colonies. Mucoid strains of group A streptococcus had only rarely been isolated from throat cultures in recent years. However, during these focal outbreaks of acute rheumatic fever, mucoid strains of group A streptococcus were commonly isolated from patients, family members, and members of the surrounding community.
In addition to the specific characteristics of the infecting group A streptococcus, the risk of a particular person developing acute rheumatic fever is also dependent upon various host factors. The incidence of both initial attacks and recurrences of acute rheumatic fever peaks in children aged 5–15 yr, the age of greatest risk for group A streptococcal pharyngitis. Patients who have had one attack of acute rheumatic fever tend to have recurrences, and the clinical features of the recurrences tend to mimic those of the initial attack. In addition, there appears to be a genetic predisposition to acute rheumatic fever. Studies in twins have shown a higher concordance rate of acute rheumatic fever in monozygotic than in dizygotic twin pairs. Recent investigations have also demonstrated an association between the presence of specific HLA markers and a B-cell alloantigen and susceptibility to acute rheumatic fever.
The pathogenic link between a group A streptococcal infection of the upper respiratory tract and an attack of acute rheumatic fever, characterized by organ and tissue involvement far removed from the pharynx, is still not clear. One of the major obstacles to understanding the pathogenesis of acute rheumatic fever and rheumatic heart disease has been the inability to establish an animal model. Several theories of the pathogenesis of acute rheumatic fever and rheumatic heart disease have been proposed, but only two are seriously considered: the cytotoxicity theory and the immunologic theory.
The cytotoxicity theory suggests that a group A streptococcal toxin may be involved in the pathogenesis of acute rheumatic fever and rheumatic heart disease. Group A streptococcus produces several enzymes that are cytotoxic for mammalian cardiac cells. For example, streptolysin O has a direct cytotoxic effect on mammalian cells in tissue culture, and most of the proponents of the cytotoxicity theory have focused on this enzyme. However, one of the major problems with the cytotoxicity hypothesis is its inability to explain the latent period between an episode of group A streptococcal pharyngitis and the onset of acute rheumatic fever.
An immune-mediated pathogenesis for acute rheumatic fever and rheumatic heart disease has been suggested by the clinical similarity of acute rheumatic fever to other illnesses produced by immunopathogenic processes and by the latent period between the group A streptococcal infection and the acute rheumatic fever. The antigenicity of a large variety of group A streptococcal products and constituents, as well as the immunologic cross-reactivity between group A streptococcal components and mammalian tissues, also lends support to this hypothesis. Common antigenic determinants are shared between certain components of group A streptococcus (e.g., M protein, protoplast membrane, cell wall group A carbohydrate, capsular hyaluronate) and specific mammalian tissues (e.g., heart, brain, joint). For example, certain M proteins (M1, M5, M6, and M19) share epitopes with human tropomyosin and myosin. Additionally, the involvement of group A streptococcal superantigens such as pyrogenic
exotoxins in the pathogenesis of acute rheumatic fever has been proposed.
Clinical Manifestations and Diagnosis.
Because no clinical or laboratory finding is pathognomonic for acute rheumatic fever, T. Duckett Jones in 1944 proposed guidelines to aid in diagnosis and to limit overdiagnosis. The Jones criteria, as revised in 1992 by the American Heart Association (Table 168–1 (Table Not Available) ), are intended only for the diagnosis of the initial attack of acute rheumatic fever and not for recurrences. There are five major and four minor criteria and an absolute requirement for evidence (microbiologic or serologic) of recent group A streptococcal infection. The diagnosis of acute rheumatic fever can be established by the Jones criteria when a patient fulfills two major criteria or one major and two minor criteria and meets the absolute requirement. Even with strict application of the Jones criteria, overdiagnosis as well as underdiagnosis of acute rheumatic fever may occur. There are three circumstances in which the diagnosis of acute rheumatic fever can be made without strict adherence to the Jones criteria. Chorea may occur as the only manifestation of acute rheumatic fever. Similarly, indolent carditis may be the only manifestation in patients who first come to medical attention months after the onset of acute rheumatic fever. Finally, although most patients with recurrences of acute rheumatic fever fulfill the Jones criteria, some may not.
There are five major criteria. The presence of two major criteria with evidence (microbiologic or serologic) of recent group A streptococcal infection fulfills the Jones criteria.
Migratory Polyarthritis. Arthritis occurs in about 75% of patients with acute rheumatic fever and typically involves larger joints, particularly the knees, ankles, wrists, and elbows. Involvement of the spine, small joints of the hands and feet, or hips is uncommon. Rheumatic joints are generally hot, red, swollen, and exquisitely tender; even the friction of bedclothes is uncomfortable. The pain can precede and can appear to be disproportionate to the other findings. The joint involvement is characteristically migratory in nature; a severely inflamed joint can become normal within 1–3 days without treatment, as one or more other large joints become involved. Severe arthritis can persist for several weeks in untreated patients. Monoarticular arthritis is unusual unless anti-inflammatory therapy is initiated prematurely, aborting the progression of the migratory polyarthritis. If a child with fever and arthritis is suspected of having acute rheumatic fever, it frequently is useful to withhold salicylates and observe for migratory progression. A dramatic response to even small doses of salicylates is another characteristic feature of the arthritis, and the absence of such a response should suggest an alternative diagnosis. Rheumatic arthritis is typically not deforming. Synovial fluid in acute rheumatic fever usually has 10,000–100,000 white blood cells/mm3 with a predominance of neutrophils, a protein of about 4?g/dL, a normal
TABLE 168.1-1 -- Guidelines for the Diagnosis of Initial Attack of Rheumatic Fever (Jones Criteria, Updated 1992)
Guidelines for the diagnosis of rheumatic fever: Jones criteria, updated 1992. JAMA 1992;268:2069–73. Copyright American Medical Association.
glucose, and forms a good mucin clot. Frequently, arthritis is the earliest manifestation of acute rheumatic fever and may correlate temporally with peak antistreptococcal antibody titers. There is an apparent inverse relationship between the severity of arthritis and the severity of cardiac involvement.
Carditis. Carditis and resultant chronic rheumatic heart disease are the most serious manifestations of acute rheumatic fever and account for essentially all of the associated morbidity and mortality. Rheumatic carditis is characterized by pancarditis, with active inflammation of myocardium, pericardium, and endocardium. Cardiac involvement during acute rheumatic fever varies in severity from fulminant, potentially fatal exudative pancarditis to mild, transient cardiac involvement. Endocarditis (valvulitis), which is manifest by one or more cardiac murmurs, is a universal finding in rheumatic carditis, whereas the presence of pericarditis or myocarditis is variable. Myocarditis and/or pericarditis without evidence of endocarditis is rarely due to rheumatic heart disease. Most cases consist of either isolated mitral valvular disease or combined aortic and mitral valvular disease. Isolated aortic or right-sided valvular involvement is uncommon. Serious and long-term illness is related entirely to valvular heart disease as a consequence of a single attack or recurrent attacks of acute rheumatic fever. Valvular insufficiency is characteristic of both acute and convalescent stages of acute rheumatic fever, whereas valvular stenosis usually appears several years or even decades after the acute illness. In developing countries, however, where acute rheumatic fever often occurs at a younger age, mitral stenosis and aortic stenosis may develop sooner after acute rheumatic fever than in developed countries, and can occur in young children.
Acute rheumatic carditis usually presents as tachycardia and cardiac murmurs, with or without evidence of myocardial or pericardial involvement. Moderate-to-severe rheumatic carditis can result in cardiomegaly and congestive heart failure with hepatomegaly and peripheral and pulmonary edema. Echocardiographic findings include pericardial effusion, decreased ventricular contractility, and aortic and/or mitral regurgitation. Mitral regurgitation is characterized by a high-pitched apical holosystolic murmur radiating to the axilla. In patients with significant mitral regurgitation, this may be associated with an apical mid-diastolic murmur of relative mitral stenosis. Aortic insufficiency is characterized by a high-pitched decrescendo diastolic murmur at the upper left sternal border. Echocardiographic demonstration of valvular regurgitation without accompanying auscultatory evidence does not satisfy the Jones criteria for carditis.
Carditis occurs in about 50–60% of all cases of acute rheumatic fever. Recurrent attacks of acute rheumatic fever in patients who had carditis with the initial attack are associated with high rates of carditis. The major consequence of acute rheumatic carditis is chronic, progressive valvular disease, particularly
valvular stenosis, which can require valve replacement and predispose to infective endocarditis.
Chorea. Sydenham chorea occurs in about 10–15% of patients with acute rheumatic fever and usually presents as an isolated, frequently subtle, neurologic behavior disorder. Emotional lability, incoordination, poor school performance, uncontrollable movements, and facial grimacing, exacerbated by stress and disappearing with sleep, are characteristic. Chorea occasionally is unilateral. The latent period from acute group A streptococcal infection to chorea is usually longer than for arthritis or carditis and can be months. Onset can be insidious, with symptoms being present for several months before recognition. Clinical maneuvers to elicit features of chorea include (1) demonstration of milkmaid's grip (irregular contractions of the muscles of the hands while squeezing the examiner's fingers), (2) spooning and pronation of the hands when the patient's arms are extended, (3) wormian movements of the tongue upon protrusion, and (4) examination of handwriting to evaluate fine motor movements. Diagnosis is based on clinical findings with supportive evidence of group A streptococcal antibodies. However, in patients with a long latent period from the inciting streptococcal infection, antibody levels may have declined to normal. Although the acute illness is distressing, chorea rarely if ever leads to permanent neurologic sequelae.
Erythema Marginatum. Erythema marginatum is a rare (<3% of patients with acute rheumatic fever) but characteristic rash of acute rheumatic fever. It consists of erythematous, serpiginous, macular lesions with pale centers that are not pruritic. It occurs primarily on the trunk and extremities, but not on the face, and it can be accentuated by warming the skin.
Subcutaneous Nodules. Subcutaneous nodules are a rare (=1% of patients with acute rheumatic fever) and consist of firm nodules approximately 1?cm in diameter along the extensor surfaces of tendons near bony prominences. There is a correlation between the presence of these nodules and significant rheumatic heart disease.
The two clinical minor manifestations are arthralgia (in the absence of polyarthritis as a major criterion) and fever (typically temperature =102°F and occurring early in the course of illness). The two laboratory minor manifestations are elevated acute-phase reactants (e.g., C-reactive protein, erythrocyte sedimentation rate) and prolonged PR interval on electrocardiogram (first-degree heart block). However, a prolonged PR interval alone does not constitute evidence of carditis or predict long-term cardiac sequelae.
RECENT GROUP A STREPTOCOCCUS INFECTION.
An absolute requirement for the diagnosis of acute rheumatic fever is supporting evidence of a recent group A streptococcal infection. Acute rheumatic fever typically develops 2–4 wk after an acute episode of group A streptococcal pharyngitis at a time when clinical findings of pharyngitis are no longer present and when only 10–20% of the throat culture or rapid streptococcal antigen test results are positive. One third of patients have no history of an antecedent pharyngitis. Therefore, evidence of an antecedent group A streptococcal infection is usually based on elevated or increasing serum antistreptococcal antibody titers. A slide agglutination test (Streptozyme) has been introduced, and it is purported to detect antibodies against five different group A streptococcal antigens. Although this test is rapid, relatively simple to perform, and widely available, it is less standardized and less reproducible than other tests and should not be used as a diagnostic test for evidence of an antecedent group A streptococcal infection. If only a single antibody is measured (usually antistreptolysin O), only 80–85% of patients with acute rheumatic fever have an elevated titer; however, 95–100% have an elevation if three different antibodies (antistreptolysin O, anti-DNase B, antihyaluronidase) are measured. Therefore, when acute rheumatic fever is suspected clinically, multiple antibody tests are performed. Except for patients with chorea, clinical findings of acute rheumatic fever generally coincide with peak antistreptococcal antibody responses. Most patients with chorea have elevation of antibodies to one or more group A streptococcal antigens, although these antibodies may be waning. The diagnosis of acute rheumatic fever should not be made in patients with elevated or increasing streptococcal antibody titers who do not fulfill the Jones criteria because such titer changes may be coincidental. This is most often true in younger, school-aged children, many of whom have group A streptococcal pyoderma in the summer or unrelated group A streptococcal pharyngitis during the winter and spring months.
The differential diagnoses of rheumatic fever include many infectious as well as noninfectious illnesses ( Table 168–2 ). When children present with arthritis, a collagen vascular disease must be considered. Rheumatoid arthritis in particular must be distinguished from acute rheumatic fever. Children with rheumatoid arthritis tend to be younger and usually have less joint pain relative to their other clinical findings than those with acute rheumatic fever. Spiking fevers, lymphadenopathy, and splenomegaly are more suggestive of rheumatoid arthritis than acute rheumatic fever. The response to salicylate therapy is also much less dramatic with rheumatoid arthritis than with acute rheumatic fever. Systemic lupus erythematosus can usually be distinguished from acute rheumatic fever on the basis of the presence of antinuclear antibodies with systemic lupus erythematosus. Other causes of arthritis, such as gonococcal arthritis, malignancies, serum sickness, Lyme disease, sickle cell disease, and reactive arthritis related to gastrointestinal infections (e.g., Shigella, Salmonella, Yersinia) should also be considered.
When carditis is the sole major manifestation of suspected acute rheumatic fever, viral myocarditis, viral pericarditis, Kawasaki disease, and infective endocarditis should also be considered. Patients with infective endocarditis may present with both joint and cardiac manifestations. These patients can usually be distinguished from patients with acute rheumatic fever by blood cultures and the presence of associated findings (e.g., hematuria, splenomegaly, splinter hemorrhages). In general, the absence of auscultatory evidence of a significant cardiac murmur excludes the diagnosis of acute rheumatic carditis.
When chorea is the sole major manifestation of suspected acute rheumatic fever, Huntington chorea, Wilson disease, systemic lupus erythematosus, and various encephalitides should also be considered. These other diseases are usually identified by the history, laboratory studies, and clinical findings.
All patients with acute rheumatic fever should be placed on bed rest and monitored closely for evidence of carditis. They can be allowed to ambulate as soon as the signs of acute inflammation have subsided. However, patients with carditis require longer periods of bed rest.
Once the diagnosis of acute rheumatic fever has been established and regardless of the throat
TABLE 168.1-2 -- Differential Diagnosis of Acute Rheumatic Fever
Reactive arthritis (e.g., Shigella, Salmonella, Yersinia)
Systemic lupus erythematosus
Sickle cell disease
Congenital heart disease
Systemic lupus erythematosus
Mitral valve prolapse
culture results, the patient should receive 10 days of orally administered penicillin or erythromycin, or a single intramuscular injection of benzathine penicillin to eradicate group A streptococcus from the upper respiratory tract. After this initial course of antibiotic therapy, the patient should be started on long-term antibiotic prophylaxis.
Anti-inflammatory agents (e.g., salicylates, corticosteroids) should be withheld if arthralgia or atypical arthritis is the only clinical manifestation of presumed acute rheumatic fever. Premature treatment with one of these agents may interfere with the development of the characteristic migratory polyarthritis and thus obscure the diagnosis of acute rheumatic fever. Agents such as acetaminophen can be used to control pain and fever while the patient is being observed for more definite signs of acute rheumatic fever or for evidence of another disease.
Patients with typical migratory polyarthritis and those with carditis without cardiomegaly or congestive heart failure should be treated with oral salicylates. The usual dose of aspirin is 100?mg/kg/24?hr divided qid PO for 3–5 days, followed by 75?mg/kg/24?hr divided qid PO for 4 wk. Determination of the serum salicylate level is not necessary unless the arthritis does not respond or signs of salicylate toxicity (e.g., tinnitus, hyperventilation) develop. There is no evidence that nonsteroidal anti-inflammatory agents are any more effective than salicylates.
Patients with carditis and cardiomegaly or congestive heart failure should receive corticosteroids. The usual dose of prednisone is 2?mg/kg/24?hr in 4 divided doses for 2–3 wk followed by a tapering of the dose that reduces the dose by 5?mg/24?hr every 2–3 days. At the beginning of the tapering of the prednisone dose, aspirin should be started at 75?mg/kg/24?hr in 4 divided doses for 6 wk. Supportive therapies for patients with moderate-to-severe carditis include digoxin, fluid and salt restriction, diuretics, and oxygen. The cardiac toxicity of digoxin is enhanced with myocarditis.
Termination of the anti-inflammatory therapy may be followed by the reappearance of clinical manifestations or of laboratory abnormalities. These “rebounds” are best left untreated unless the clinical manifestations are severe; salicylates or steroids should be reinstated in such cases.
Because chorea often occurs as an isolated manifestation after the resolution of the acute phase of the disease, anti-inflammatory agents are usually not indicated. Sedatives may be helpful early in the course of chorea; phenobarbital (16–32?mg q 6–8?hr PO) is the drug of choice. If phenobarbital is ineffective, then haloperidol (0.01–0.03?mg/kg/ 24?hr divided bid PO) or chlorpromazine (0.5?mg/kg q 4–6?hr PO) should be initiated.
The arthritis and chorea of acute rheumatic fever resolve completely without sequelae. Therefore, the long-term sequelae of rheumatic fever are usually limited to the heart.
Patients with cardiac valvular disease secondary to acute rheumatic fever are at increased risk of developing infective endocarditis during episodes of transient bacteremia. The antibiotic regimens used to prevent recurrences of acute rheumatic fever are inadequate for protection against infective endocarditis. Therefore, these patients require short-term antibiotic prophylaxis before surgical or dental procedures that are associated with transient bacteremia. The current recommendations of the American Heart Association regarding infective endocarditis prophylaxis should be followed ( Chapter 429 ). The importance of good dental hygiene in the prevention of infective endocarditis should also be stressed. Patients who have had rheumatic fever but have no evidence of residual valvular disease do not require endocarditis prophylaxis.
The prognosis for patients with acute rheumatic fever depends on the clinical manifestations present at the time of the initial episode, the severity of the initial episode, and the presence of recurrences. Approximately 70% of the patients with carditis during the initial episode of acute rheumatic fever recover with no residual heart disease; the more severe the initial cardiac involvement, the greater the risk of residual heart disease. Patients without carditis during the initial episode are unlikely to have carditis with recurrences. In contrast, patients with carditis during the initial episode are likely to have carditis with recurrences, and the risk of permanent heart damage increases with each recurrence. Patients who have had acute rheumatic fever are susceptible to recurrent attacks following reinfection of the upper respiratory tract with group A streptococcus. Therefore, these patients require long-term continuous chemoprophylaxis.
Before antibiotic prophylaxis was available, 75% of patients who had an initial episode of acute rheumatic fever had one or more recurrences during their lifetime. These recurrences were a major source of morbidity and mortality. The risk of recurrence is highest immediately after the initial episode and decreases with time.
Approximately 20% of patients who present with “pure” chorea who are not put on secondary prophylaxis develop rheumatic heart disease within 20 yr. Therefore, patients with chorea, even in the absence of other manifestations of rheumatic fever, require long-term antibiotic prophylaxis.
Prevention of both initial and recurrent episodes of acute rheumatic fever depends on controlling group A streptococcal infections of the upper respiratory tract. Prevention of initial attacks (primary prevention) depends on identification and eradication of the group A streptococcus that produces episodes of acute pharyngitis. Individuals who have already suffered an attack of acute rheumatic fever are particularly susceptible to recurrences of rheumatic fever with any subsequent group A streptococcus upper respiratory tract infection, whether or not they are symptomatic. Therefore, these patients should receive continuous antibiotic prophylaxis to prevent recurrences (secondary prevention).
Appropriate antibiotic therapy instituted before the 9th day of symptoms of acute group A streptococcal pharyngitis is highly effective in preventing first attacks of acute rheumatic fever from that episode. However, about one third of patients with acute rheumatic fever do not recall a preceding episode of pharyngitis.
Secondary prevention is directed at preventing acute group A streptococcal pharyngitis in patients at substantial risk of recurrent acute rheumatic fever. Secondary prevention requires continuous antibiotic prophylaxis, which should begin as soon as the diagnosis of acute rheumatic fever has been made and immediately after a full course of antibiotic therapy has been completed. Because patients who have had carditis with their initial episode of acute rheumatic fever are at a relatively high risk of having carditis with recurrences and of sustaining additional cardiac damage, they should receive antibiotic prophylaxis well into adulthood and perhaps for life.
Patients who did not have carditis with their initial episode of acute rheumatic fever have a relatively low risk of carditis with recurrences. Antibiotic prophylaxis may be discontinued in these patients when they reach their early 20s and after at least 5 yr have elapsed since their last episode of acute rheumatic fever. The decision to discontinue prophylactic antibiotics should be made only after careful consideration of potential risks and benefits and of epidemiologic factors such as the risk of exposure to group A streptococcal infections.
The regimen of choice for secondary prevention is a single intramuscular injection of benzathine penicillin G (1.2 million IU) every 4 wk (Table 168–3 (Table Not Available) ). In certain high-risk patients, and in certain areas of the world where the incidence of rheumatic fever is particularly high, use of benzathine penicillin G every 3 wk may be necessary because levels of penicillin may decrease to marginally effective amounts after 3 wk. In compliant patients, continuous oral antimicrobial prophylaxis can be
TABLE 168.1-3 -- Secondary Prevention of Rheumatic Fever
used. Penicillin V given twice daily and sulfadiazine given once daily are equally effective when used in such patients. For the exceptional patient who is allergic to both penicillin and sulfonamides, erythromycin given twice daily may be used. REFERENCE