Rheumatic Fever

13/09/2013 by admin | Cardiology

Definition

  1. Haemolytic inflammatory disease that occurs following a Group A streptococcal infection, (such as strep throat or scarlet fever).
  2. caused by antibody cross-reactivity that can complicate the heart, joints, skin, and brain, the illness typically develops two to three weeks after a streptococcal infection.
  3. Complications seen in 2% of all RF patients.

 

Incidence

  1. Acute rheumatic fever commonly appears in children between the ages of 5 and 15, with only 20% of first-time attacks occurring in adults

 

Epidemiology

Rheumatic fever is common worldwide and responsible for many cases of damaged heart valves. In Western countries, it became fairly rare in the western world since the 1960s, probably due to widespread use of antibiotics to treat streptococcus infections

Presenting complaint

  1. Non-descript flu like symptoms – although can cause cross reactivity as mentioned above

 

Diagnostic tools/investigations

  1. Modified ‘Duckett-Jones criteria’
  2. According to revised Jones criteria, the diagnosis of rheumatic fever can be made when two of the major criteria, or one major criterion plus two minor criteria, are present along with evidence of streptococcal infection. Exceptions are chorea and indolent carditis, each of which by itself can indicate rheumatic fever.

 

Major criteria

  1. Migratory polyarthritis: a temporary migrating inflammation of the large joints, usually starting in the legs and migrating upwards.
  2. Carditis: inflammation of the heart muscle which can manifest as congestive heart failure with shortness of breath, pericarditis with a rub, or a new heart murmur due to vegetations on valve (order of prevelance of valve failure: M[R]>A>T>P).
  3. Subcutaneous nodules(‘Aschoff bodies’): painless, firm collections of collagen fibers over bones or tendons. They commonly appear on the back of the wrist, the outside elbow, and the front of the knees.
  4. Erythema marginatum: a long lasting rash that begins on the trunk or arms as macules and spreads outward to form a snake like ring while clearing in the middle. This rash never starts on the face and it is made worse with heat.
  5. Sydenham’s chorea (St. Vitus’ dance): a characteristic series of rapid movements without purpose of the face and arms. This can occur very late in the disease.

 

Minor criteria

  1. Fever
  2. Arthralgia: Joint pain without swelling
  3. Raised ESR / CRP
  4. Leukocytosis
  5. ECG showing features of heart block, such as a prolonged PR interval
  6. Supporting evidence of Streptococcal infection: elevated or rising Antistreptolysin O titre or DNAase
  7. Previous episode of rheumatic fever or inactive heart disease

 

Other signs and symptoms

  1. Abdominal pain
  2. Nose bleeds

 

Aetiology

Auto-immune dysregulation post-infection with group A streptococcus.

Pathophysiology

  1. This cross-reactivity is a Type II hypersensitivity reaction and is termed molecular mimicry.
  2. Strep infection causes T2 cells to activate the B cells to become plasma cells and induce the production of antibodies against the cell wall of Streptococcus. However the antibodies may also react against the myocardium and joints producing the symptoms of rheumatic fever.
  3. Characteristic Aschoff bodies, composed of swollen eosinophilic collagen surrounded by lymphocytes and macrophages can be seen on light microscopy. The larger macrophages may become Aschoff giant cells.

 

Hereditary? Infective? How does it spread?

Treatment and management (conservative/medical/surgical)

  1. Prevention of recurrence is achieved by eradicating the acute infection and prophylaxis with antibiotics.
  2. The American Heart Association recommends daily or monthly prophylaxis continue long-term, perhaps for life (ie penicillin)
  3. Aspirin (and steroids) is the drug of choice and should be given at high doses of 100 mg/kg/day (s/e’s = and salicylate poisoning, and Reye’s syndrome in children)

 

Prognosis

  1. Although the disease seldom occurs, it is serious and has a mortality of 2–5%  
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