Rheumatic Fever:
Rheumatic fever is an autoimmune inflammatory disease that occurs after an untreated infection of the throat caused by Group A beta-hemolytic Streptococcus.
It usually affects children between 5 to 15 years of age.
Pathophysiology:
Group A Streptococcus (pharyngitis)
│
Immune response triggered
│
Molecular mimicry occurs
(The bacterial M protein resembles a protein in human tissue)
│
Autoimmune attack on host tissues
│
┌────────────┬────────────┬─────────────┐
Heart Joints Skin Brain
(Pancarditis, Migratory Erythema Sydenham
Aschoff bodies) polyarthritis) marginatum, chorea
nodules
Jones Criteria for Rheumatic Fever:
Evidence of Recent GAS Infection
At least one of the following must be present:
• Positive throat culture for GAS
• Positive rapid antigen test
• Elevated antistreptolysin O (ASO) or anti-DNase B titers.
Major Criteria
1. Carditis – can be clinical (murmur, heart failure) or subclinical (echocardiographic findings)
2. Polyarthritis – migratory arthritis, usually affecting large joints
3. Chorea (Sydenham’s chorea) – involuntary movements
4. Erythema marginatum – pink, non-pruritic, ring-shaped rash
5. Subcutaneous nodules – firm, painless nodules over joints, spine, or scalp
Minor Criteria
1. Fever
2. Arthralgia (joint pain without swelling)
3. Elevated acute phase reactants – ESR or CRP
4. Prolonged PR interval on ECG.
Diagnosis:
-With major manifestations: 2 major criteria or 1 major + 2 minor criteria
-Plus evidence of recent GAS infection.
Rheumatic Heart Disease (RHD):
It is the cardiac manifestation of rheumatic fever. It is associated with inflammation of all parts of the heart, but valvular inflammation and scarring produce the most clinical features.
Pathophysiology:
Group A Streptococcus Infection (Pharyngitis)
↓
Immune Response → production of antibodies cross-reacting with heart tissue (Molecular mimicry)
↓
Acute Rheumatic Fever (Inflammation)
Formation of Aschoff bodies (granulomatous lesions in h
Affects endocardium, myocardium, pericardium
↓
Valve Damage
↓
Inflammation and fibrinoid necrosis of valves
↓
Healing & Fibrosis
(Scarring, thickening, calcification of valves)
↓
Rheumatic Heart Disease (Chronic Valvular Lesions)
↓
Most commonly: Mitral valve → stenosis or regurgitation
(mitral valve>Aortic valve>tricuspid valve>pulmonary valve)
Complications:
Heart failure
Atrial fibrillation
Stroke (due to embolism from atrial fibrillation)
Infective endocarditis.
Conclusion:
Rheumatic fever is an autoimmune sequela of untreated or inadequately treated Group A streptococcal pharyngitis, presenting with multisystem inflammatory features. While acute rheumatic fever may resolve, repeated or severe episodes often result in chronic valvular damage, known as rheumatic heart disease. RHD is characterized by progressive fibrosis, thickening, and calcification of heart valves, most commonly affecting the mitral and aortic valves, leading to significant morbidity and mortality worldwide.
Early recognition and management of streptococcal infections, timely treatment of acute rheumatic fever, and long-term secondary prophylaxis remain the cornerstones of preventing rheumatic heart disease and its complications. Together, these conditions highlight the critical importance of infection control, early diagnosis, and preventive strategies in reducing the global burden of rheumatic heart disease.