Rheumatic Fever/ Rheumatic Heart Disease: 
Rheumatic Fever is an acute, immune mediated disease that occurs after an episode of beta hemolytic streptococcal pharyngitis and often involves the heart.
Major Clinical Manifestations/ Criteria for Diagnosis.
1. Migratory poly arthritis of large joints.
2. Carditis
3. Subcutaneous nodules
4. Erythma marginatum
5. Sydenhom chorea ( it is a neurological disorder with involuntary purpose less movements.)

Minor Clinical manifestations/ Diagnostic criteria
1. Fever
2. Arthralgias.
3. Elevated acute phase reactants.

Jones Criteria for diagnosis of Rheumatic Fever.
Physician should diagnose Rheumatic fever if there is
1. History of beta hemolytic streptococcal infection.
2. Presence of Two major manifestations or one major and two minor manifestations.

1. Aschoff bodies (foci of fibrinoid necrosis)
2. Anitschkow cells (these are plasma cells surrounded by macrophages)
3. Pancarditis
4. Bread and butter perecarditis (because of serofibrinous pericardial exudate)
5. Verrucae or valvular vegetations (fibrinoid necrosis within the cusps of valves)
6. Maccullum plaques.
7. Thickening of leaflets of valves.
8. Fibrous bridging across commisural fusions called fish mouth button hole stenosis.

9. Sub endocardial thickening usually in left atrium.

Antibodies directed against M protein of certain strains of streptococci cross react with tissue strains of streptococci cross react with tissue glycoprotein of heart, joints and other tissues, thus initiating the inflammation and tissue damage.