Rheumatic fever

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Rheumatic fever is a multisystem autoimmune vasculitic disease triggered by infection by group A streptococci (GAS), which is relapsing in nature. [1] It is becoming rare in the UK, probably because of improvements in public health, hygiene and housing. It has been thought to be largely a disease of poor areas areas such as the Maori, Australian Aborigines [2] and Soweto, South Africa but recently there have been occurrences in middle income areas of the USA. It is the commonest cause globally of acquired heart disease in childhood and adolescence.[3]

Contents

Aetiology

Recent infection with particularly virulent Group A streptococcus strains. These are typically related to throat infection, although in Australia skin infection seems to be more important. Strains that cause acute rheumatic fever seem to be distinct from those that cause post-streptococcal acute glomerulonephritis. There is an association with the HLA gene groupings of the patient. M-proteins on the bacterium cross sensitize with human proteins. Some of these have superantigen properties.

Clinical

Some 3-4 weeks after a sore throat the patient develops a fever, sweating, fatigue and joint pains, which are classically in the large joints. The tachycardia may be out of proportion to the fever, indicating carditis and a new heart murmur may be present (classically the Carey-Coombs murmur) as may be a pericardial friction rub.

There is no one specific test for diagnosis but criteria originally devised by Dr T Duckett Jones in 1944 are used [4]

Jones criteria

These have been upgraded several times [5]

Major Criteria

  • Carditis - A pancarditis, leading to valve damage, heart block, cardiomyopathy. Pericarditis may be present but is never an isolated finding.
  • Polyarthritis - major joints “fleeting and flitting”
  • Sydenham's Chorea - (75%) but may not appear for 6 months
  • Subcutaneous nodules – (5-7%) over extensor surfaces, seen in chronic phase
  • Erythema marginatum - characteristic serpiginous non-pruritic rash

Minor criteria

2 major else 1 major and 2 minor criteria are required for formal diagnosis, plus supporting evidence of recent Group A streptococcus infection:

  • Positive throat culture or rapid antigen test - <25% may be present by diagnosis
  • Increasing streptococcal antibody ASO titre or similar.

Strict adherence to the criteria may not be useful in certain circumstances eg chorea appearing many months after the initial illness.

Investigations

Blood tests

Imaging

Chest X-ray may give an indication of enlargement of the heart. Echo can sometimes show subclinical carditis - although not included in the criteria, most would consider it as significant.

Biopsy

Endomyocardial biopsy may be available. Aschoff nodules are characteristic.

Electrocardiography

Examine for rhythm disturbance and evidence of carditis or pericarditis.

Treatment

Medical

  • bed rest is advised to reduce the work of the heart and relieve the joints. It has probably been more strict than needed.
  • NSAIDs are given for arthralgia/arthritis. Aspirin is given at high dose but there is not a great deal of evidence that this affects the progress of the disease. Aspirin would not normally be used in children because of the risk of Reye’s syndrome.
  • penicillin should be given to eliminate all streptococcus still present even if swabs are negative (10 day course of phenoxypenicillin, else single dose IM benzathine penicillin. Erythromycin for penicillin allergic.
  • steroids are often given if there is evidence of severe inflammation, but Cochrane concluded that if anything, outcome is worse after steroids.
  • heart failure and chorea if present should be treated appropriately.
  • See prophylaxis below

Complications

  • heart damage – valve scarring
  • Subacute bacterial endocarditis may cause emboli to be released from infected vegetations forming on damaged valves. This is more likely in recurrent bouts where valve damage has occurred as a result of the original episode(s)
  • chorea

Surgical

Nothing initially. Valve surgery may be required in later years.

Prevention

Penicillin prophylaxis prevents second or subsequent bouts. IM benzathine penicillin 3-4 weekly is preferred else oral penicillin can be used. Even if carditis is not present at presentation, it may develop as part of a relapse hence prophylaxis is still indicated. The risk of relapse is highest in the first 5 years after presentation. Prophylaxis should be continued lifelong if there is carditis.

NB - note US guidelines were updated in 2009.[6]

Vaccination

An M-protein vaccine is being developed, however there is concern that it may actually prime for rheumatic fever rather than preventing it. [7]

Isolation

The disease is not infectious, but the initiating strain is, of course.

Notification

Is not required in the UK, but it is probably important to know if there is a virulent GAS strain circulating. Mass prophylaxis campaigns have been undertaken successfully in the past.

Prognosis

Just under half of patients will develop second and subsequent bouts. Those with severe carditis at presentation and with relapses have the worse prognosis. Young children (under 5 yrs) are more likely to get carditis, and more likely to get long term valve disease.

References

  1. Stollerman GH (1997) Rheumatic fever, Lancet ;349, 935–42.
  2. Acute rheumatic fever and rheumatic heart disease in the top end of Australia's Northern Territory Med J Aust. 1996;164(3):146-9
  3. Davidson’s Principles and Practice of Medicine. 2006 Boon NA (ed) Churchill Livingstone Elsevier, Edinburgh
  4. Oxford Textbook of Medicine Warrell, David, Cox, Timothy M, Firth, John D, Benz, Edward J Oxford University Press 2004 ISBN: 0198529988 2004
  5. Guidelines for the Diagnosis of Rheumatic Fever: Jones Criteria, Updated 1992 JAMA 268: 2069-2073
  6. Gerber MA, Baltimore RS, Eaton CB, Gewitz M, Rowley AH, Shulman ST, Taubert KA. Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. Circulation. 2009 Mar 24; 119(11):1541-51.(Link to article – subscription may be required.) (full text available here)
  7. Guilherme L, Faé KC, Higa F, Chaves L, Oshiro SE, Freschi de Barros S, Puschel C, Juliano MA, Tanaka AC, Spina G, Kalil J. Towards a vaccine against rheumatic fever. Clinical & developmental immunology. 2006 Jun-Dec; 13(2-4):125-32.(Link to article – subscription may be required.)
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