Transcript ACUTE RHEUMATIC FEVER - Welcome to Selam Higher Clinic

ACUTE
RHEUMATIC FEVER
By:Dawit Ayele
Definition
 Rheumatic fever is an inflammatory disease
that occurs as a delayed, non-suppurative
sequela of upper respiratory infection with
group A streptococci.
Etiology
 Antecedent infection with specific
microorganism- Gp A streptococci
 At specific site- upper respiratory tract-nowhere
else
 Heavily encapsulated, as evidenced by their
growth as mucoid colonies on blood agar plates.
 Predominant strains 3, 5, 18, 24, and others
Epidemiology
 3% of individuals with untreated gp A
streptococci will develop RF.
 Most often occurs in children; the peak agerelated incidence is b/n 5 and 15 years.
 Risk factors for outbreak:
-lower standards of living esp.crowding,
-the organism itself
-the degree of host/herd immunity to the
prevalent M-types in an affected community
Pathogenesis
 Study Hypothesis of ‘antigenic mimicry’:
1)Similarity between the group-specific CHO of the
gp A streptococcus & the glycoprotein of heart
valves,
-2)the molecular similarity among the
streptococcal cell membrane, strept M ptn
sarcolemma,& other moieties of human
myocardial cell.
 Possiblity of predisposing genetic
influencedifferences in immune response to
strept
Clinical feature
-- most notably affect the heart, joints, skin,
subcutaneous tissue, and central nervous system.
POSSIBLE FEATURES
 High fever, prostration, crippling polyarthritis
 Lassitude, tachycardia, new cardiac murmurs
 Acute pericarditis
 Fulminant heart failure
 Sydenham's chorea without fever or toxicity
 Acute abdominal pain mimicking appendicitis
 Varying combinations of the above
Diagnosis
 No specific test to establish Dx
 *Clinical+supportive evidence from
microbiology & clinical immunology lab
 1944 Jones proposed standard criteria
 1992 updated Jones published by AHA
 To fullfill the dx requires either 2 major or 1
major & 2 minor + evidence of antecedent
streptococcal infection
The Jones Criteria





Major
Carditis
Migratory polyarthritis
Sydenham’s chorea
Subcutaneous nodules
Erythema marginatum
+ Supporting evidence of
a recent gp A strept
infection(throat culture
or rapid antigen /ab
test ASO-80%+)
Minor
 Clinical-fever
-arthralgia
 Lab-↑acute phase
reactants- (↑ ESR)
-prolonged PR
Carditis
 40-60% of RF cases have evidence of carditis
 Pancarditis involve- pericardium, myocardium&
endocardium
 Cx-sinus tachycardia,
-murmur of MR
-S3 gallop
-pericardial friction rub
-cardiomegaly
20%-subtle mitral valve abnormality w/o audible
murmur(echo dx)
Carditis…
 Commonly affected valves:
-Mitral(pure ms or ms/mr)
-Aortic-isolated is rare-mitral valve is almost
always simultaneously affected
-tricuspid & pulmonic –not commonly
affected
Migratory Polyarthritis
 In as many as 75% of cases
 Extremely painful joint pain & swelling
 Most often affects-ankles, wrists,knees&
elbows
 Not usually affected-small joints of hands or
feet;seldom involves hip joints
Sydenham’s chorea
 CNS d/o
 <10% of patients
 It may happen in as long as several months
from initial strept infection
Subcutaneous nodules & erythema
marginatum
 Uncommon manifestations
 Nodules found over extensor surface of joints
 Are seen most often in patients with long
standing Rheumatic heart dis.
 EM usually concentrated on the trunk as
evanescent macular eruption with rounded
borders
Treatment
Two necessary therapeutic approach to ARF pts
1)Anti –Strept antibiotic treatment:for all patients
with ARF whether culture is +/Conventional-10 days course of oral penicillin v
5oo mg po bid or erythromycin for penicillin
allergy
Choise of many-Benz. Penicillin G 1.2 mill IU
2)Treatment for clinical manifestation of the
disease-arthritis-ASA upto 2 gm qid
-CHF –conventional medical measures
-Chorea-reassurance for most-resolves in
6wks to 6 mths
2o prophylaxis
 AHA recommendations- Benzanthine penicillin
1.2 million IU IM Q 4 weeks or for oral penicillin
V(250mg 2x/day)or oral sulfadiazine 1 gm daily.
 For those with higher risk Benz. Penicillin q 3 wks
is more effective in decreasing risk of recurrence.
 Risk of recurrence is highest during the 1st 5 yrs
after attack—2ry prophylaxis is always given for at
least these period.
 Continued rx for high risk exposure gpstudents,teachers,medical& military personnel.
 Many believe documented recurrences &/or
documented RVD should receive 20 px for life!!
THANK YOU