Rheumatic fever

Question 1

When is the peak incidence of rheumatic fever?

Answer 1

5-15 yo

Question 2

What triggers rheumatic fever and how long after the initial infection does rheumatic fever usually start?

Answer 2

Lancefield group A beta-haemolytic streptococci

Usually starts 2-4 weeks later

Question 3

How is rheumatic fever diagnosed?

Answer 3

Revised Jones criteria:
evidence of a recent strep infection plus 2 major criteria or 1 major and 2 minor

Evidence of group A beta-haemolytic strep
positive throat culture, rapid strep antigen test positive, elevated or rising strep antibody titre, recent scarlet fever

Major criteria:
carditis - tachycardia, murmurs, pericardial rub, CCF, cardiomegaly, conduction defects
arthritis - migratory, flitting ‘polyartheritis’ usually affects large joints
subcutaneous nodules - small mobile painless nodules on extensor surfaces of joints and spine
Erythema marginatum - rash with red raised edges and clear centre, mainly seen on trunk thighs and arms
sydenham’s chorea - occurs late, unilateral or bilateral involuntary semi-purposeful movements

Minor criteria:
fever
raised CRP or ESR
arthralgia (not if arthritis is major criteria)
prolonged PR interval (not if carditis is major criteria)
previous rheumatic fever

Question 4

What is the management of rheumatic fever?

Answer 4

bed rest until CRP normal for 2 weeks
benzylpenicillin 0.6-1.2g IV stat then penicillin V 250-500mg QDS for 10 days
analgesia for carditis/arthritis - add oral prednisolone if mod-severe carditis
immobilise joints in severe arthritis
Haloperidol or diazepam for chorea

Question 5

What is the order in which the valves are commonly affected?

Answer 5

mitral - 70%
aortic - 40%
tricuspid - 10%
pulmonary - 2%

Question 6

What is given as secondary prophylaxis to rheumatic fever and when should it be given?

Answer 6

Penicillin V 250mg/12h PO
if carditis for 10 years (if persistent valvular disease the continue until at least 40yo)
If no carditis, 5-year prophylaxis is sufficient