acute rheumatic fever, by dr. emmanuel rusingiza. my name is emmanuel rusingiza. i am a pediatriccardiologist at kigali university teaching hospital. this morning i'm going to talk aboutthe diagnosis and management or acute rheumatic fever. as outlined, we will go through thedefinition and overview of acute rheumatic fever, the epidemiology, pathophysiology,diagnosis, investigations, differential diagnosis, and management. overview. acute rheumatic fever is defined as a delayedautoimmune response to an untreated group a streptococcal infection, mainly affectingthe throat. acute rheumatic fever may involve
the heart, the joints, the central nervoussystem, and/or the skin. the signs and symptoms may include any or all of the following: arthritis,fever, carditis, rash, sydenham's chorea, and subcutaneous nodules. group a streptococcal throat infections occurin children throughout the world, with peak ages between 5 and 15 years. the number ofchildren affected in each region varies depending on environmental conditions, level of poverty,quality and availability of health care. over the past century, acute rheumatic fever andrheumatic heart disease have become rare in developed countries as living conditions havebecome more hygienic and less crowded with improved nutrition and access to appropriatemedical care.
repeated group a streptococcal infectionsand recurrent acute rheumatic fever can lead to chronic heart valve damage that is calledrheumatic heart disease. rheumatic heart disease requires expensive heart valve surgery. ifdamaged heart valves are not repaired or replaced by major open heart surgery, the conditionis often fatal. epidemiology. it is estimated that about 15.6million people are affected world-wide, and among them, 2.4 million are children between5 and 14 years old in developing countries. acute rheumatic fever and rheumatic heartdisease are the disease of poverty but they are indicated in industrialized countriessince 20th century, as thought previously. the following factors increase the risk ofdeveloping acute rheumatic fever: overcrowding
and poor standards of housing, reduced accessto health care, and living in tropical climates. acute rheumatic fever is most common in childrenbetween the ages of 5 and 15 years. it is less common after the age of 35 years andis rare under 4 years and over 40 years of age. pathophysiology. as pathophysiology, not everyoneis susceptible to acute rheumatic fever, and not all group a streptococcus strains arecapable of causing acute rheumatic fever in a susceptible host. it is likely that 3-5%of people in any population have an inherent susceptibility to acute rheumatic fever, althoughthe basis of susceptibility is unknown. some strains of group a streptococcus are calledrheumatogenic, particularly streptococcal
m-protein, although the basis of rheumatogenicityis also unknown. this is a picture of a patient who presentstonsillopharynx infection by group a streptococcus. it shows severely inflamed tonsils with presenceof pus. and the culture has revealed group a streptococcus. so acute rheumatic feveris sequela of untreated or inadequately treated group a streptococcus infection of the tonsillopharynx. studies have concluded that there is a molecularmimicry between group a streptococcus antigens and human host tissue that is believed tobe the basis of pathogen host cross-reactivity, best documented with cardiac proteins suchas myosin, laminin, and vimentin. point of clarification. in acute rheumaticfever, the patient's immune system produces
antibodies against the m-protein of the groupa streptococcus bacterium. these antibodies appropriately bind to the antigen on the surfaceof the bacteria to eradicate the primary infection. but occasionally, these same antibodies cross-reactwith the patient's own cardiac proteins, given the structural similarities between thoseproteins and the end protein of group a strep. this molecular mimicry is believed to be thebasis for cardiac pathology related to acute rheumatic fever and rheumatic heart disease. the patient's immune response is initiatedafter initial exposure to the bacteria. however, there is a latency period of about three weeksbefore the patient develops symptoms of acute rheumatic fever. this is due to the lag betweeninitial antibody production and the cross-reactivity
of these antibodies with the patient's owntissue proteins. at the time of development of acute rheumatic fever symptoms, the hostimmune system has eradicated the initial group a strep infection. the progression of the disease is done asfollowing. it starts initially by a group a streptococcus throat infection which, dueto a certain number or factors, leads to acute rheumatic fever. and during repetitive episodesof group a streptococcus infection in the future, it causes recurrent acute rheumaticfever. that leads to rheumatic heart disease with all its complications. diagnosis. the diagnosis of acute rheumaticfever remains a clinical decision. it's the
original specific laboratory test. it is knownthat overdiagnosis of acute rheumatic fever will lead to unnecessary treatment over along time, while underdiagnosis leads to further attacks of acute rheumatic fever, cardiacdamage, and premature death. the diagnosis of acute rheumatic fever isusually guided by jones criteria developed in 1944 and adopted most recently by the worldhealth organization. the jones criteria include major criteria and minor manifestations, plusevidence of preceding group a streptococcus infection. this table summarizes the jones criteria.and the first column shows the major manifestations that include, arthritis, carditis, subcutaneousnodules, erythema marginatum, and sydenham's
chorea. the column in the middle shows minormanifestations, which are fever, arthralgia, prolonged pr interval on ecg, and raised ecror crp. the evidence of recent group a streptococcusinfection include the positive culture of the throat swab, the raised anti-streptolysino titer, and the raised anti-dnase b. arthritis is the common symptom, and it is characterizedby pain, redness, and swelling in the joints. and it affects commonly the big joints, likethe ankles, the knees, the wrists, the elbow, and less commonly the small joints. it isoften the first complaint, and arthritis is usually migratory, disappearing in one jointas it begins in another. the carditis, which is defined as an inflammationof the heart, is commonly present as a heart
murmur. chest pain and/or difficulty breathingmay be present in severe cases. less commonly, people with acute rheumatic fever presentwith subcutaneous nodules and erythema marginatum with specific characteristics. subcutaneous nodules are painless lumps seenon the outside surfaces of major joints. they are often present for about one to two weeksduration, and are more commonly present when the patient also has evidence of carditits.erythema marginatum starts out as painless, flat, pink patches on the skin that spreadoutward in a circular pattern. this is often an early symptom of acute rheumatic feverand often spares the face. this rash may be present for months after the onset of acuterheumatic fever.
sydenham's chorea is a twitching, jerkingmovements and muscle weakness most obvious in the face, hands, and feet. it is more commonin teenagers and females. it may begin up to three to four months after the streptococcalinfection. it may appear on both sides or only one side of the body, and often appearswithout other symptoms. point of clarification. the mean durationof chorea is documented in the literature as 12-15 weeks, but please note that someepisodes may persist for as long as 6-12 months. the fever is defined as a core temperaturegreater than 38 degrees, and it can go up to high values. the evidence of group a streptococcusinfection is required to confirm a case of acute rheumatic fever with the above signsand symptoms. group a streptococcus may not
be found on a throat swab, since the infectionmay be resolved at the time of onset of acute rheumatic fever symptoms. serum anti-streptolysin o titer reaches thepeak level around three to six weeks after infection and starts to fall at six to eightweeks. serum anti-dnase b reaches a peak level up to six to eight weeks after infection,and starts to fall at around three months after the infection. the first episode of acute rheumatic fevercan be confirmed if there are two major criteria, or one major criteria and two minor manifestationsplus an evidence of preceding group a streptococcus infection. recurrent acute rheumatic feverwithout rheumatic heart disease can be confirmed
as the previous first episode. the recurrentacute rheumatic fever with existing rheumatic heart disease can be confirmed if there aretwo minor manifestations, plus evidence of preceding group a streptococcus infection. however, different regions have slightly modifiedguidelines to assist clinicians with local variations in acute rheumatic fever presentation.in this regard, the involvement of only one joint, also called monoarthritis, polyarthralgiain children who are at high risk of acute rheumatic fever, and subclinical carditisproved by echocardiogram have been proposed to be among the major criteria. the differential diagnosis is made with septicarthritis, connective tissue, valvular arthropathy,
sickle cell anemia, mitral valve prolapse,infective endocarditis, and many other diseases which present the similar clinical manifestationslike acute rheumatic fever. investigations. the investigations shouldbe fbc, esr, crp, blood cultures if febrile-- especially for the differential diagnosiswith infective endocarditis-- the immunologic markers of group a streptococcus infection,which are aso and anti-dnase b, throat swab, ekg, chest x-ray-- if there is an evidenceof colitis-- and echocardiogram. this echocardiography image shows a severelydamaged mitral valve which is thickened. look at the posterior leaflet which is also retracted.and during systole, there is a very bad coaptation of the mitral leaflets that results in massivemitral regurgitaiton and dilation of the left
atrium. this patient was admitted for severeheart failure due to rheumatic heart disease. management. the treatment of the acute illnessincludes benzathine penicillin g, single injection, or oral penicillin for 10 days. and in caseof allergy, erythromycin is indicated. relief of symptoms and signs with non-steroid anti-inflammatorydrugs, especially aspirin or corticosteroids. carbamazepine and valproic acid can be givenfor severe cases of sydenham's chorea. the management of acute rheumatic fever shouldbe based on the following principles: admission for acute diagnosis, receive clinical care,and education about preventing further episodes of acute rheumatic fever. initial echocardiogramis very important to identify and measure the heart valve damage. long-term preventivemanagement should be organized before this
discharge. the long term management includes regularsecondary prophylaxis, regular medical review, regular dental review, echocardiogram followingeach episode of acute rheumatic fever, and routine echocardiogram. secondary prophylaxisshould be done by benzathine penicillin g im every three to four weeks. and the standarddose is 1.2 million units for patients who weigh 30 kgs or greater. and the half doseof 600,000 units for patients who are under 30 kgs. penicillin v can be used if benzathine penicillin injectionsare not tolerated or injections are contraindicated. the standard dose is one tab of 250 milligramsoral, twice daily. here, i would like to insist
on the necessity to give the injectable formof penicillin because it has shown better results compared to the oral form of penicillin.erythromycin is given if there is proven allergy to penicillin. the standard dose is 250 milligramsoral twice daily. the duration of secondary prophylaxis should be done as following. when acute rheumatic fever is identified withoutproven carditis, the minimum duration should be five years after the last episode of acuterheumatic fever, or until 18 years. for the mild to moderate forms of rheumatic heartdisease, the minimum duration should be 10 years after the last acute rheumatic feveror until the age of 25 years. for severe rheumatic heart disease and following cardiac surgeryfor rheumatic heart disease, patients should
continue medication for life. thank you for watching. please help us improve the content by providingus with some feedback.
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