Rheumatic Fever Flashcards
what is the definition of rheumatic fever
inflammatory multisystem disorder
autoimmune
following a beta-haemolytic streptococci infection
what group of strep is a beta-haemolytic streptococci infection
group A strep
what is the GAS (a beta-haemolytic strepococci infection) which causes rheumatic fever
s. pyogenes
initially a throat infection
what is the aetiology of rheumatic fever
initially a streptococcal pharyngeal infection
genetic susceptibility may be present
molecular mimicry plays an important role in initiation of tissue injury (antibodies against GAS antigens cross react with host antigens)
what is the epidemiology of rheumatic fever
peak incidence 5-15yrs
mean incidence is 20 per 100,000PA
common in far east, middle east, eastern europe, south america
less common in west
what history is associated with rheumatic fever
presentation 2-5wks post GAS infection general -fever -malaise -anorexia cardiac -SOB -chest pain -palpitations joints -painful -swollen -impaired function
what criteria is used for examination in suspected rheumatic fever
duckett jones criteria
what constitutes diagnosis using the duckett jones criteria
2 or more major criteria
1 major and 2 or more minor criteria
what are the duckett jones major criteria for rheumatic fever
CASES
Carditis -new murmur(Carey Coombs murmur) a mid diastolic murmur due to mitral valve inflammation -pericarditis -pericardial effusion/rub -cardiomegaly -HF Arthritis -migrating polyarthritis -swelling, redness, tenderness of large joints Sydenham's Chorea -rapid, involuntary, irregular movements -slurred speech -more common in females Erythema marginatum(20% of cases) -short periods of red rashes with raised edges -present on trunk and proximal limbs -form crescent/ring-shaped patches Subcutaneous nodules -small, firm, painless nodules - on joints and tendons
what are the duckett jones minor criteria for rheumatic fever
PEACH FEVER
Prolonged PR and QT intervals (if carditis not present)
ESR raised
Arthralgia (if arthritis or present)
Acute phase reactants raised (WCC, ESR, CRP)
CRP raised
History of previous RF/rheumatic heart disease/recent streptococcal infection
FEVER
what would indicate recent streptococcal infection
positive throat cultures
raised antistreptolysin O titre
what investigations would be performed in suspected rheumatic fever
1 bloods -FBC(raised WCC) -raised ESR/CRP -raised antistreptolysin O titre 2 throat swab -culture for GAS infection -streptococcal antigen test 3 ECG -'saddle shaped' ST elevation and PR segment depression(feature of pericarditis) -arrhythmias 4 echo -pericardial effusion -myocardial thickening/dysfunction -valvular dysfunction
what is the management for rheumatic fever
Conservative
-strict bed rest for 4wks
Medical
-anti-inflammatories (high dose aspirin, corticosteroids if severe)
-antibiotics (oral penicillin V for 10 days for strep infection, long term antibiotics to prevent recurrence such as benzathine penicillin G IM every 4wks)
-treat carditis by treating HF (diuretics)
-treat chorea with diazepam/haloperidol
Surgical
-only if medical therapy fails
what complications are associated with rheumatic fever
recurrence
-more common with cardiac damage
-precipitated by streptococcal infection
chronic rheumatic valvular disease
-more common when acute RF presents with carditis
-scarring, deformation, dysfunction of mitral/aortic valves after 10-20yrs
what is the prognosis associated with rheumatic fever
acute RF may last 3months if untreated
females more likely to develop mitral stenosis