Rheumatic fever Flashcards
Define:
An inflammatory disorder occurring following group A beta-haemolytic streptococci infection (GAS)
Aetiology:
Not fully understood
Occurs 2-5 weeks following pharyngeal infection - only 2%.
There is antigenic mimicry leads to cross reaction of GAS antigen to heart valves
Risk factors:
Genetic susceptibility
Malnutrition
Poverty
Epidemiology:
Common in developing countries but rare in the west
peaks from 5-15 year olds
mean incidence 19/100,000
symptoms:
2-5 weeks after the throat infection
General:
malaise
fever
anorexia
Joints:
painful swollen
reduced movement and function
cardiac:
breathlessness
chest pain
palpitation
Signs:
Has to have the jones criteria: evidence of strept infection and 2 major or one major and one minor.
Evidence of GAS - positive throat culture, strept antigen test, elevated strept antibody titre and recent scarlet fever
what is the major criteria:
CASES
Carditis: tachycardia, murmurs (mitral/aortic regurgitation), pericardial rub, cardiomegaly, conduction defects
Arthritis: usually affects larger joints
Subcutaneous nodules: small firm painless nodules seen on extensor surfaces, joints and tendons
Erythema marginatum: geographical-type rash with red, raised edges and clear centre mainly on trunk and proximal limbs
Sydenham’s chorea: rapid, involuntary, irregular movements with flowing/dancing quality
what is the minor criteria:
Pyrexia
Raised ESR/CRP
Arthralgia (only if arthritis not present as major criteria)
Prolonged PR interval (only if carditis not present as major criteria)
Previous rheumatic fever
Investigations:
Bloods: FBC (inc WCC), inc ESR/CRP, rising antistreptolysin O titre
Throat swab: culture for GAS, rapid streptococcal antigen test
ECG: saddle-shaped ST elevation and PR segment depression (features of pericarditis), arrhythmias
Echocardiogram: pericardial effusion, myocardial thickening or dysfunction, valvular dysfunction
