definition: acute, immunologically mediated multisystemic inflammatory disease following group a...
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Definition: Acute, immunologically mediated multisystemic inflammatory disease following group A streptococcal pharyngitis .affecting joints, skin, heart and brain
•Occures in 3% of patients with group A
streptococcal pharyngitis.
•Increase risk of reactivation with new
pharyngeal infections
Diagrammatic structure of the group A beta hemolytic streptococcus
Capsule
Cell wall
Protein antigens
Group carbohydrate
Peptidoglycan
Cyto.membrane
Cytoplasm
…………………………………………………...
Antigen of outer protein cell wall of GABHS induces antibody response in victim which result in autoimmune damage to heart valves, sub cutaneous tissue,tendons, joints & basal ganglia of brain
Pathogenesis of rheumatic feverPathogenesis of rheumatic fever
ARF is a hyper sensitivity reaction induced by group A streptococci.
Antibodies directed against M proteins of streptococci cross-react with glycoproteins of heart,joints,skin and brain.
Oncet of symptoms is 2-3 weeks after infection,and absence of bacteria in leasions.
Multinucleated giant cells, macrophages
And T lymphpcytes seen only in the heart
Found in myocardial biopsy
Multinucleated giant cells, macrophages
And T lymphpcytes seen only in the heart
Found in myocardial biopsy
Clinical featuresClinical features
Fever ,anorexia ,Lethargy ,joint pain 2-3 weeks after an episode of streptococcal pharingitis
Arthritis : migratory ,asymmetrical affecting large joints {elbows ,wrists, knees ,ankles }
Skin lesions: Erythema marginatum , subcutaneous nodules
Cardites : usually pancarditis ,cardiomegaly , murmurs, tachycardia ,chest pain ,
Sydenhams chorea :occurs 3 m after acute RF
Rare manifestations: pleurisy ,pleural effusion ,pneomonia
Peak incidence 5-15 years
Migratory asymmetrical non -deforming
Polyarthritis affects large joints
Responds quickly to aspirin
Occurs in 75%
Joints are painful, red and warm
For 1-7 days
Transient skin rash red macules over trunk proximal part of extremities pale center red margins which coalesce as snake like appearance, non pruritic, >10%
10%-15% ,painless mobile over joints with normal skin color, small and transient
0.5-2mm in size, occures 3w after onset
Associated with carditis
Dyspnoea, crdiomegaly, pericarditis, murmers, tachycardia, chest pain
May be pancarditis incidence decrease with age 30% in adults
ECG changes
Occures in 10% of patients, it is late manifestation of RF 3m
Nonpurpossive, nonrepititive involantory movement of hands, face, or feet, more in females ,
Explosive speech ..Emotional liability ………………. last 2-6m , spontaneous recovery is usual
25% go on to develop chronic RVD
TR : halloperidole, phenobarbitone, Na-vlproate
Carbimezapine
St.Vitus`s danceSt.Vitus`s dance
Major manifestations :*Cardtids *Polyarthritis * Chorea
*Erythema marginatum *Subcutaneous nodules
Minor manifestations :*Fever *Arthralgia *Previous RF Raised ESR or CR-protein * Leukocytosis * 1st an 2nd AV block
Evidence of preceding streptococcal infection: *Raised ASO titer * Positive throat swab culture For diagnosis of RF: 2 Major or { 1 Major + 2 Minor } + Evidence of recent streptococcal Infection.
Jones criteria for diagnosis of RF
IInvestigationsnvestigations::
*Nonspecific : raised ESR, CRP, WBC * Evidence of preceeding strept. Infection:
_ Throat swab culture for group A beta haemolytic strept.
_ ASO titer > 200 u { adults }, and > 300 u { children}* Evidence of carditis:
_ Chest XR : cardiomegaly, pulmonary congestion _ ECG : 1st and 2nd AV block , ST , T , changes
_ ECHO. : chamber dilatation , valve abnormalities
Treatment of acute rheumatic feverTreatment of acute rheumatic fever * Benzathine penicillin 1.2m units i.m to eliminate residual
Strepto. infection
* Bed rest and supportive measures : rest till symptoms improve
* Aspirin 60-120mg /kg b.w in 6 doses for 3-4 ws * Corticosteroids in cases of carditis or severe arthritis
prednisolone 1-2 mg/kg b.w in divided doses 2-3 ws tapering 20%/w
* Secondary prevention _ Benzathine penicillin 1.2 million units i.m monthly
or phenoxymethylpenicillin 250mg b.d or erythromycin until 21 year at least 5 years after last attack of acute
RF
Chronic rheumatic carditisChronic rheumatic carditis *occurs in 50% of those affected with RF with carditis
*History of RF or chorea elicited only in 5o% of patients with chronic RVD
*MV is affected in 90% of cases ,AV next most frequent then TV and least frequently PV
isolated MS occurs in 25% of all cases* Symptoms usually delayed for years or decades after acute
RF * Predominant pathology is progressive fibrosis mainly
affecting the valves causing thickening ,deformity and calcification ending in varying degree of stenosis and /or
regurgitation *Clinical features and complications depend on valves
involved and include * Cardiac murmurs *Cardiac hypertrophy and dilatation
* Congestive heart failure * Thromboembolic incidents* Infective endocarditis * Arrhythmias mainly AF