Rheumatic Fever
Definition
•Diffuse non suppurative inflammatory disease of connective tissue as a sequalae to Group A beta hemolytic streptococcal infection of the throat by rheumatogenic strains, primarily involving heart, blood vessels, joints, subcut. tissue and CNS
Magnitude of Pattern
•Common cause of CV morbidity and mortality in underdeveloped and developing countries
•Less in developed world
Prevalence of RHD in school children
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•
•
•
6 / 1000 (5 CITIES – 1 Cm2)
Aetiopathogenesis
Incompletely understood
•Non suppurative sequelea to ‘GAS’
•Repeated infection important
•Genetic predisposition ?
•Autoimmunity – Antigenic mimicry between st.cell wall component and human myocardium, valvular glycoprotein etc.
•Delayed immune response to infection with group.A beta hemolytic streptococci.
•After a latent period of 1-3 weeks, antibody induced immunological damage occur to heart valves, joints, subcutaneous tissue & basal ganglia of brain
Determinants
•Severity of throat infection
–Severe exudative infection - upto 3%
–Mild sporadic – 0.5 to 1%
•Immune response (ASO) – 1 to 5%
•GAS persisting in throat
•Previous RF : many times
•Established RHD – very high
–Recurrence rate – 50% - 1st year
10% after 5 years
Pathologic Lesions
•Fibrinoid degeneration of connective tissue,inflammatory edema, inflammatory cell infiltration & proliferation of specific cells resulting in formation of Aschoff nodules, resulting in
-Pancarditis in the heart
-Arthritis in the joints
-Aschoff nodules in the subcutaneous tissue
-Basal gangliar lesions resulting in chorea
•Rheumatic fever licks the joint & bites the heart
Incubation period
•1 to 5 weeks
•Shortest for Arthritis
•Longest for Chorea
Clinical features
Commonest age – 5- 15 years
Arthritis
•Migratory polyarthritis
•Mainly - major joints, no residual deformity
•Usually mild in young children esp. <>
•Prominent in older children and adolescents
•Occur upto 30%, more in girls
•May appear even 6 m after the attack of RF
•Clumsiness, deterioration of handwriting, emotional lability or grimacing of face
•Clinical signs- pronator sign, jack in the box sign, milking sign of hands
•Occur in 2 %
•Painless, pea-sized, palpable nodules:- 0.5 - 2 cm, mainly over extensor surfaces of
joints, spine, scapulae & scalp
•Typically appear > 3 wk after the onset
•Always associated with severe carditis
•Rarely seen in our population -.5 to 2%
•Transient, serpiginous, non-itchy, pale center with red irregular margin, mainly trunks/ limbs
•Often associated with carditis
Carditis - Pancarditis
Endocarditis – Valvulitis, Mitral & /or aortic
•Significant murmur – MR, AR, Carey Coombs
Myocarditis
Cardiomegaly–Clinical, X-Ray CCF, Prolonged PR, relative Tachycardia, Soft S1, S3
Pericarditis
•Pericardial rub ± effusion
Diagnosis of RF
•No single symptom
•No single sign
•No single lab test
Revised Jones Criteria for Guidance in Diagnosis
•1994 – by Dr. T. Duckett Jones
•Modified by AHA in 1956, 1965, 1982, 1992
•1987 – WHO study group accepted 1982 AHA criteria
Revised Jones Criteria, AHA 1992
Major:
Carditis
Arthritis
Chorea
Erythema marginatum
Subcutaneous nodules
Minor:
Clinical: Arthralgia
Fever
Lab: level of acute phase reactants –ESR & C-reactive protein
Prolonged PR interval
Essential criteria:
Evidence of antecedent group A Streptococcal infection
Diagnosis of rheumatic fever highly probable
If
Two major criteria
or
One major & two minor criteria
With
Essential criteria satisfied
Relaxation of Criteria
•Chorea as sole manifestation (other causes excluded)
•Insidious onset / Late onset carditis
•Established RHD
–One major criteria
–Fever with arthralgia + increased acute phase reactants
If evidence of recent GAS infection present
Acute Carditis in Chronic RHD often difficult
•New murmur
•Sudden increase in heart size
•Recent onset CHF
•Pericardial rub
•Erythema marginatum / Subcutaneous nodules
Previous carditis – recurrence of RF ® Carditis almost always present
Supportive evidence of Streptococcal infection
•ASO + others
•Throat culture – positive
•Recent scarlet fever
•History of sore throat – commonest viral
Laboratory Findings
•High ESR, Elevated C-reactive protein
•Anemia, leucocytosis
•ECG - prolonged PR interval, non specific ST-T changes rarely heart blocks
•2D Echo cardiography - valve edema, mitral regurgitation, LA &
Streptococcal antibody tests
ASO - most commonly used
•> 200 IU suggestive, rising titre in 2 to 4 wks
•Peaks in 4to 6 wks , remain high for 4 to 6 wks and comes down
•Sensitivity- 80%
•Specificity low – skin infection, other strep. Inf.
Others
–Antistreptokinase, Antihyaluronidase
–Anti DNAse, Antistreptozyme(most sensitive)
Throat Culture
•Positive in minority (latency, antibiotic Use)
•About 20 % school children – carrier state
Differential Diagnosis
•Rheumatoid Arthritis
•SLE
•Infective Endocarditis
•Serum sickness
•Gonococcal Arthritis
•Tuberculosis
•Viral myopericarditis
•Leukaemias
Overdiagnosis - Problems
•Trauma + anxiety – parent + children
•Unnecessary prophylaxis – risk
•Missing another disease
Under Diagnosis
No prophylaxis
Risk of reactivation
Natural History of RF
•Period of activity
75% - 6 weeks
90% - 12 weeks
< style="mso-spacerun:yes"> - upto 6 months (Chronic RF)
•Arthritis
> 12 years – 80%
3 to 6 years – 50%
•Carditis
<>
14 to 17 years – 30%
Natural History – RF with Carditis
•Initial attack, no carditis – excellent prognosis
•Initial attack, mild carditis – 70% normal heart after 10 years
•Initial attack, severe carditis – 40% normal heart at 10 years
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