Acute Rheumatic Fever
Acute Rheumatic Fever
multisystem immunologic disorder that usually follows a strept infection Characterized by inflammatory reactions involving: heart, joints, basal ganglia
Chronic Rheumatic Heart Disease
occurs is first attack of ARF is severe or with recurrent attacks Chronically damaged valves show fishmouth or buttonhole deformity--> mitral and aortic stenosis- CHF
Aschoff Body
the pathognomonic lesion of RF Are reactive histiocytes- Fuse and form Aschoff multinucleated giant cells.
Jones Major Criteria for ARF
1. Migratory asymmetric Polyarthritis 2. Carditis 3. Sydenham's chorea due to involvement of Basal G 4. Subcutaneous nodules 5. Erythema marginatum
Complications of Chronic Rheumatic Heart Disease
Bacterial endocarditis- damaged valves are easily seeded by bacteria Mural thrombi: stasis of blood leads the the formation of thromboemboli- infarcts Congestive hear failure: due to aortic stenosis
Endocarditis
Characterized by inflammation of valve surfaces Leading to development of Sterile verrucoid appearing vegetations (platelet and fibrin clots) along the line of closure of the valve
Erythema marginatum
Circular ring of erythema with central clearing.
Diagnosis of ARF
Clinical history and Two of five major criteria or One Major and two minor criteria
Jones Minor Criteria for ARF
Fever , Arthralgia Leukocytosis, elevated ESR ,C-reactive protein (CRP) and antistreptolysin O (ASO titers). Previous rheumatic fever or rheumatic heart disease
Fibrinous pericarditis
Fibrin deposits on pericardium on visceral and parietal layers "bread and butter appearance" Precordial chest pain with friction rub for clinical diagnosis
Pathogenesis
Immune mediated- follows GAS infection Abs against the M protein cross react with human tissue(heart and joints) --> molecular mimcry
Migratory asymmetric Polyarthritis
MC (~ 75%) initial presentation of ARF Occurs in large joints (Knees) and small joints (wrists, ankles) Joints are tender and swollen- there is no permanent joint damage
What valve is most commonly involved?
Mitral Valve Can cause Mitral valve regurgitation or Aortic valve regurgitation May result in CHF.
What is the most common cause of death in Acute Rheumatic Fever
Myocarditis Myocardium becomes flabby with hypocontraction leading to heart failure
Do the vegetations embolize?
No
Epidemiology
Occurs at 5-15 years of ages Develops 1 - 5 wks after group A beta hemolytic streptococcal pharyngitis or tonsillits relapse may lead to rheumatic heart disease
What layers of the heart are affected?
Pancarditis: involves all 3 layers endocardium (especially valves), myocardium, and epicardium.
Sydenham's chorea
Reversible rapid, involuntary movements affecting all muscles Mainly due to the involvement of Basal Ganglia
What are the primary symptoms of acute rheumatic fever?
The major clinical manifestations of ARF are migratory polyarthritis, carditis, subcutaneous nodules, erythema marginatum, and Sydenham chorea. The attack rate for ARF is approximately 3% following infection with group A beta-hemolytic streptococci.
Subcutaneous nodules
They are painless, firm, movable nodules and are usually located on the extensor surface of joints Fibrinoid necrosis surrounded by histiocytes
