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Acute Rheumatic Fever

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acute rheumatic fever

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  • Acute Rheumatic Fever

  • Cause

    ARF is believed to be an immunologic lesion that occurs as a delayed sequela of group A streptococcal infection of the pharynx but not of the skin. The attack rate of ARF after streptococcal infection varies with the severity of the infection, ranging from 0.3% to 3%.

    Important predisposing factors include family history of rheumatic fever, low socioeconomic status (poverty, poor hygiene, medical deprivation), and age between 6 and 15 years (with a peak incidence at 8 years of age).

  • Pathology

    The inflammatory lesion is found in many parts of the body, most notably in the heart, brain, joints, and skin. Valvular damage most frequently involves the mitral, less commonly the aortic, and rarely the tricuspid and pulmonary valves.

    Aschoff bodies in the atrial myocardium are believed to be characteristic of rheumatic fever. These consist of inflammatory lesions associated with swelling, fragmentation of collagen fibers, and alterations in the staining characteristics of connective tissue.

  • Clinical Manifestations

    ARF is diagnosed by the use of revised Jones criteriaThe criteria are three groups of important clinical and laboratory findings: (1) five major manifestations (2) four minor manifestations (3) supporting evidence of an antecedent group A streptococcal infection.

  • HISTORY

    History of streptococcal pharyngitis, 1 to 5 weeks (average, 3 weeks) before the onset of symptoms, is common.

    The latent period may be as long as 2 to 6 months (average, 4 months) in cases of isolated chorea. Pallor, malaise, easy fatigability, and other history, such as epistaxis (5% to 10%) and abdominal pain, may be present.

    Family history of rheumatic fever frequently is positive.

  • MAJOR MANIFESTATIONSArthritis

    Arthritis, the most common manifestation of ARF (70% of cases) involves large joints (e.g., knees, ankles, elbows, wrists). Often more than one joint, either simultaneously or in succession, is involved

    characteristic migratory nature of the arthritis. Swelling, heat, redness, severe pain, tenderness, and limitation of motion are common. The arthritis responds dramatically to salicylate therapy; if patients treated with salicylates (with documented therapeutic levels) do not improve in 48 hours, the diagnosis of ARF probably is incorrect.

    Such patients have been categorized as having poststreptococcal reactive arthritis; the relationship of this disease to acute rheumatic fever remains undetermined.

  • Carditis

    Carditis occurs in 50% of patients:

    Tachycardia (out of proportion to the degree of fever) is common; its absence makes the diagnosis of myocarditis unlikely.

    A heart murmur of valvulitis (caused by mitral regurgitation [MR] and/or aortic regurgitation [AR]) is almost always present; without the murmurs of MR and/or AR, carditis should not be diagnosed.

    the presence of MR or AR by echo and Doppler studies, without accompanying auscultatory findings, cannot be taken as the sole criterion for valvulitis.

    Pericarditis (friction rub, pericardial effusion, chest pain, and ECG changes) may be present.

    Cardiomegaly on chest x-ray films is indicative of pericarditis, pancarditis, or congestive heart failure (CHF).

    Signs of CHF (gallop rhythm, distant heart sounds, cardiomegaly) are indications of severe carditis.

  • Erythema Marginatum

    Occurs in

  • Subcutaneous Nodules

    Found in 2% to 10% of patients, particularly in those with recurrences.

    Hard, painless, nonpruritic, freely movable, swelling, and 0.2 to 2 cm in diameter.

    Symmetris, singly or in clusters, on the extensor surfaces of both large and small joints, over the scalp, or along the spine.

    Not transient, lasting for weeks, and have a significant association with carditis.

  • Sydenham's Chorea

    Sydenham's chorea (St. Vitus' dance) is found in 15% of patients with ARF. more often in prepubertal girls (8 to 12 years) than in boys. neuropsychiatric disorder consisting of both neurologic signs (choreic movement and hypotonia) and psychiatric signs (e.g., emotional lability, hyperactivity, separation anxiety, obsessions and compulsions). begins with emotional lability and personality changes. spontaneous, purposeless movement of chorea (which lasts 4 to 18 months), followed by motor weakness.

  • The distractability and inattentiveness outlast the choreic movements.

    The adventitious movements, weakness, and hypotonia continue for an average of 7 months (up to 17 months) before slowly waning in severity.

    Recently, elevated titers of antineuronal antibodies recognizing basal ganglion tissues have been found in over 90% of patients. The levels of the antineuronal antibody titer are positively related to the severity of choreic movements.

    These findings suggest that chorea may be related to dysfunction of basal ganglia and cortical neuronal components.

    Sydenham's Chorea

  • MINOR MANIFESTATIONS

    Arthralgia refers to joint pain without the objective changes of arthritis. It must not be considered a minor manifestation when arthritis is present.

    Fever (usually with a temperature of at least 102F [38.8C]) is present early in the course of untreated rheumatic fever.

    In laboratory findings, elevated acute-phase reactants (elevated C-reactive protein levels and elevated erythrocyte sedimentation rate) are objective evidence of an inflammatory process.

    A prolonged PR interval on the ECG is neither specific for ARF nor an indication of active carditis.

  • EVIDENCE OF ANTECEDENT GROUP A STREPTOCOCCAL INFECTION

    A history of sore throat or of scarlet fever unsubstantiated by laboratory data is not adequate evidence of recent group A streptococcal infection. Positive throat cultures or rapid streptococcal antigen tests for group A streptococci are less reliable than antibody tests because they do not distinguish between recent infection and chronic pharyngeal carriage. Antigen detection tests are very specific but not very sensitive; a negative test result should be confirmed by a conventional throat culture.

    Streptococcal antibody tests are the most reliable laboratory evidence of antecedent streptococcal infection capable of producing ARF. The onset of the clinical manifestations of ARF coincides with the peak of the streptococcal antibody response.

  • Antistreptolysin O (ASO) titer is well standardized and therefore is the most widely used test. It is elevated in 80% of patients with ARF and in 20% of normal individuals.

    Only 67% of patients with isolated chorea have an elevated ASO titer. ASO titers of at least 333 Todd units in children and 250 Todd units in adults are considered elevated.

    A single low ASO titer does not exclude ARF. If three other antistreptococcal antibody tests (antideoxyribonuclease B, antistreptokinase, and antihyaluronidase tests) are obtained, a titer for at least one antibody test is elevated in about 95% of patients.

    The antideoxyribonuclease B test is favored over other tests. Titers of 240 Todd units or greater in children and 120 Todd units or greater in adults are considered elevated.

    The Streptozyme test (Wampole Laboratories) is a relatively simple slide agglutination test, but it is less standardized and less reproducible than the other antibody tests.

  • OTHER CLINICAL FEATURES

    Abdominal pain, rapid sleeping heart rate, tachycardia out of proportion to fever, malaise, anemia, epistaxis, and precordial pain are relatively common but not specific.

    A positive family history of rheumatic fever also may heighten the suspicion but cannot be used as a diagnostic manifestation.

  • Diagnosis

    The revised Jones criteria are used for the diagnosis of ARF.

    Only the major and minor criteria and evidence of an antecedent group A streptococcal infection are included in the criteria, although other findings play a supporting role.

    A diagnosis of ARF is highly probable when either two major manifestations or one major and two minor manifestations, plus evidence of antecedent streptococcal infection, are present.

    The absence of supporting evidence of a previous group A streptococcal infection makes the diagnosis doubtful.

    Exceptions to the Jones criteria include the following three specific situations:

    Chorea may occur as the only manifestation of rheumatic fever. Indolent carditis may be the only manifestation in patients who come to medical attention months after the onset of rheumatic fever. Occasionally, patients with rheumatic fever recurrences may not fulfill the Jones criteria.

  • Tips help in applying the Jones criteria:

    Two major manifestations are always stronger than one major plus two minor manifestations.

    Arthralgia or a prolonged PR interval cannot be used as a minor manifestation in the presence of arthritis or carditis, respectively.

    The absence of evidence of an antecedent group A streptococcal infection is a warning that ARF is unlikely (except when chorea is present).

    The vibratory innocent (Still's) murmur is often misinterpreted as a murmur of MR and thereby is a frequent cause of misdiagnosis (or overdiagnosis) of ARF. The murmur of MR is a regurgitant-type systolic murmur (starting with the S1), but the innocent murmur is low pitched and an ejection type. A cardiology consultation during the acute phase minimizes the frequency of misdiagnosis.

    The possibility of the early suppression of full clinical manifestations should be sought during the history taking. Subtherapeutic doses of aspirin or salicylate-containing analgesics (e.g., Bufferin, Anacin) may suppress full manifestations.

  • Differential Diagnosis

    Juvenile rheumatoid arthritis (JRA) is often misdiagnosed as acute rheumatic fever. The following findings suggest JRA rather than ARF: involvement of peripheral small joints, symmetrical involvement of large joints without migratory arthritis, pallor of the involved joints, a more indolent course, no evidence of preceding streptococcal infection, and the absence of prompt response to salicylate therapy within 24 to 48 hours.

    Other collagen vascular diseases (systemic lupus erythematosus, mixed connective tissue disease); reactive arthritis, including poststreptococcal arthritis; serum sickness; and infectious arthritis (such as gonococcal) occasionally require differentiation.

    Virus-associated acute arthritis (rubella, parvovirus, hepatitis B virus, herpesvi ruses, enteroviruses) is much more common in adults.

    Hematologic disorders, such as sicklemia and leukemia, should be considered in the differential diagnosis.

  • Clinical Course

    Only carditis can cause permanent cardiac damage. Signs of mild carditis disappear rapidly in weeks, but those of severe carditis may last for 2 to 6 months.

    Arthritis subsides within a few days to several weeks, even without treatment, and does not cause permanent damage.

    Chorea gradually subsides in 6 to 7 months or longer and usually does not cause permanent neurologic sequelae.

  • Management

    When ARF is suggested by history and physical examination, one should obtain the following laboratory studies: complete blood count, acute-phase reactants (ESR and CRP), throat culture, ASO titer, chest x-ray films, and ECG.

    Cardiology consultation is indicated to clarify whether there is cardiac involvement; two-dimensional echo and Doppler studies are usually performed at that time.

    Benzathine penicillin G, 0.6 to 1.2 million IU/IM, is given to eradicate streptococci. This serves as the first dose of penicillin prophylaxis as well. In patients allergic to penicillin, erythromycin, 40 mg/kg per day in two to four doses for 10 days, may be substituted for penicillin.

  • Anti-inflammatory or suppressive therapy with salicylates or steroids must not be started until a definite diagnosis is made. Early suppressive therapy may interfere with a definite diagnosis of ARF by suppressing full development of joint manifestations and suppressing acute-phase reactants. When the diagnosis of ARF is confirmed, one must educate the patient and parents about the need to prevent subsequent streptococcal infection through continuous antibiotic prophylaxis. In patients with cardiac involvement, the need for prophylaxis against infective endocarditis also should be emphasized.

  • Bed rest of varying duration is recommended. The duration depends on the type and severity of the manifestations and may range from a week (for isolated arthritis) to several weeks for severe carditis. Bed rest is followed by a period of indoor ambulation of varying duration before the child is allowed to return to school.

  • The erythrocyte sedimentation rate is a helpful guide to the rheumatic activity and therefore to the duration of restriction of activities. Full activity is allowed when the erythrocyte sedimentation rate has returned to normal, except in children with significant cardiac involvement.

  • Therapy with anti-inflammatory agents should be started as soon as ARF has been diagnosed.

    Prednisone (2 mg/kg per day in four divided doses for 2 to 6 weeks) is indicated only in cases of severe carditis.

    For mild to moderate carditis, aspirin alone is recommended in a dose of 90 to 100 mg/kg per day in four to six divided doses. An adequate blood level of salicylates is 20 to 25 mg/100 mL. This dose is continued for 4 to 8 weeks, depending on the clinical response. After improvement, the therapy is with drawn gradually over 4 to 6 weeks while monitoring acute-phase reactants.

    For arthritis, aspirin therapy is continued for 2 weeks and gradually withdrawn over the following 2 to 3 weeks. Rapid resolution of joint symptoms with aspirin within 24 to 36 hours is supportive evidence of the arthritis of ARF.

  • Treatment of CHF includes some or all of the following:Complete bed rest with orthopneic position and moist, cool oxygen. Morphine sulfate, 0.2 mg/kg, at 4-hour intervals for severe CHF with respiratory distress. Restriction of sodium and fluid intake. Prednisone for severe carditis of recent onset. Digoxin (used with caution, because certain patients with rheumatic carditis are supersensitive to digitalis), beginning with half the usual recommended dose. Furosemide, 1 mg/kg every 6 to 12 hours, if indicated.

  • Management of Sydenham's chorea:

    Reduce physical and emotional stress and use protective measures as indicated. Give benzathine penicillin G, 1.2 million units, initially for eradication of streptococcus and also every 28 days for prevention of recurrence, just as in patients with other rheumatic manifestations. Without the prophylaxis, about 25% of patients with isolated chorea (without carditis) develop rheumatic valvular heart disease in 20-year follow-up.

    Anti-inflammatory agents are not needed in patients with isolated chorea.

    For severe cases, any of the following drugs may be used: phenobarbital (15 to 30 mg every 6 to 8 hours), haloperidol (starting at 0.5 mg and increasing every 8 hours to 2 g), valproic acid, chlorpromazine (Thorazine), diazepam (Valium), or steroids.

    Plasma exchange (to remove antineuronal antibodies) and IV immune globulin therapy (to inactivate the effects of the antineuronal antibodies) are in the experimental stages (by the National Institutes of Health), but the preliminary results are promising in reducing the duration of chorea.

  • Prognosis

    The presence or absence of permanent cardiac damage determines the prognosis. The development of residual heart disease is influenced by the following three factors:

    Cardiac status at the start of treatment: The more severe the cardiac involvement at the time the patient is first seen, the greater the incidence of residual heart disease.

    Recurrence of rheumatic fever: The severity of valvular involvement increases with each recurrence.

    Regression of heart disease: Evidence of cardiac involvement at the first attack may disappear in 10% to 25% of patients 10 years after the initial attack. Valvular disease resolves more frequently when prophylaxis is followed.

  • Prevention

    POPULATIONPatients with documented histories of rheumatic fever, including those with isolated chorea and those without evidence of rheumatic heart disease, must receive prophylaxis.

    DURATIONIdeally, patients should receive prophylaxis indefinitely.Many cardiologists recommend discontinuing the prophylaxis at age 21 to 25 years, provided the patient does not have evidence of valvular involvement and is not in a high-risk occupation (e.g., schoolteachers, physicians, nurses). If the patient has rheumatic valvular disease, the prophylaxis should be continued longer, possibly for life. The chance of recurrence is highest in the first 5 years after the ARF.

  • METHODS

    The method of choice for secondary prevention is benzathine penicillin G, 1.2 million units given intramuscularly every 28 days (not once a month). Alternative methods, although not as effective, are the following:

    Oral penicillin V, 250 mg, twice daily. Oral sulfadiazine, 1 g once daily (note that the sulfonamides are not effective for the prophylaxis of infective endocarditis). Oral erythromycin ethyl succinate, 250 mg, twice daily.

    PRIMARY PREVENTION

    Primary prevention of rheumatic fever is possible with a 10-day course of penicillin therapy for streptococcal pharyngitis. Primary prevention is not possible in patients who develop subclinical pharyngitis and therefore do not seek medical treatment (30%) and in patients who develop ARF without symptoms of strepto coccal pharyngitis (30%).

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