Rheumatic fever

Rheumatic fever is a multisystemic inflammatory disorder caused by type II hypersensitivity reaction following group A beta haemolytic streptococcus pharyngeal infection. Cross reaction of antibodies against protein M with other cells glycoproteins leads to involvement of other organs such as heart.  

Pathology

It principally involves the heart (pancarditis can result), joints (see article: Jaccoud arthropathy), central nervous system, skin, and subcutaneous tissue. 

Diagnosis

Jones criteria

Evidence of group A beta haemolytic streptococcus infection and 2 major or 1 major and 2 minor criterias.

• major criteria
  • migratory polyarthritis
  • pancarditis
  • Sydenham's chorea
  • erythema marginatum
  • subcutaneous nodules
• minor criteria
  • fever
  • arthralgia
  • increase in acute phase reactants (e.g. CRP/ESR)
  • previous episode of rheumatic fever or inactive heart disease
  • leukocytosis
  • ECG changes such as a prolonged PR interval (not if carditis is present as a major symptom)

Histology

• Aschoff bodies
• lymphocytes
• swollen collagen
• plump macrophages (Anitschkow cells): pathognomonic
• Anitschkow cells can fuse to become multinucleated cells (Aschoff cells)

Treatment and prognosis

Benzathine penicillin 120 IU intramusacular injuection is the drug of choice to eliminate group A streptococci. While good supportive therapy can reduce the mortality and morbidity of the disease.

The clinical course can varies greatly, but in general, ~75% of acute rheumatic attacks subside within 6 weeks.