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 and kidneys.  

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

Clinical diagnosis

Jones criteria

Evidence of group A beta haemolytic streptococcus infection and

• 2 major OR
• 1 major and 2 minor criterias 

Major criteria

1. migratory polyarthritis
2. pancarditis
3. Sydenham's chorea
4. erythema marginatum
5. subcutaneous nodules

Minor criteria

1. fever
2. arthralgia
3. increase in acute phase reactants (e.g. CRP/ESR)
4. previous episode of rheumatic fever or inactive heart disease
5. leukocytosis
6. ECG changessuch such as a prolonged PR interval(not if carditis is present as a major symptom)

Musculoskeletal manifestations 

• see article: Jaccoud arthropathy

Pathology

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 120IU IM 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.