Rheumatic fever

Question 1

what is rheumatic fever?

Answer 1

common infectious disease until mid 20th century, incidence decline in developed countries but is common in developing countries and in indigenous populations

Question 2

what has caused the fall in rheumatic fever?

Answer 2

penicillin
reduced virulence in strains of the streptococcus infection
improved living conditions

Question 3

where is rheumatic fever common

Answer 3

areas of overcrowding and poor access to healthcare
higher incidence in winter
rare in developed countries

Question 4

who does it affect?

Answer 4

typically school age children - median age = 10.4

rare before 3 and after 21

Question 5

what countries/regions is it common?

Answer 5

indigenous populations of australia, new zealand, pacific island nations and south america

Question 6

what causes rheumatic fever?

Answer 6

poverty
overcrowding 
family history 
genetic factors 
caused by group A beta-haemolytic streptococci - most commonly those with the M antigen

Question 7

pathogenesis of rheumatic fever

Answer 7

organ damage due to a type 2 hypersensitivity reaction - cross-linking of antibodies
antibodies against streptococcal M protein act against cardiac myosin
heart valves are infiltrated by T cells which are against cardiac myosin as they were activated by M antigen
mitral valve most commonly affected in acute rheumatic heart disease, but all can be affected

Question 8

when do symptoms occur?

Answer 8

1-5 weeks after infection - e.g. after sore throat

this period is shorter in reoccurrence as there is a quicker immune response

Question 9

what are the symptoms?

Answer 9

fever - 1 week
arthritis 
neurological signs/symptoms - 30% of patients 
skin signs/symptoms 
cardiac signs/symptoms

Question 10

symptoms: arthritis

Answer 10

often severe pain
unable to walk if lower limbs affected
usually asymmetrical
polyarthritis

Question 11

neurological symptoms

Answer 11

syndenham’s chorea
tourette’s syndrome
symptoms cease during sleep

Question 12

syndenham’s chorea

Answer 12

rapid purposeless movements

affecting face and upper limbs

Question 13

skin symptoms

Answer 13

subcutaneous nodules
erythema marginatum
macular/papular rash on trunk and arms
face is spared

Question 14

cardiac signs/symptoms

Answer 14

aortic regurgitation 
carey coombs' sign 
pericardial rub
tachycardia
endocarditis 
myocarditis

Question 15

austin flint’s murmur

Answer 15

aortic regurgitation

Question 16

carey coombs’ sign

Answer 16

characteristic soft diastolic murmur due to mitral valve involvement

Question 17

signs on echo

Answer 17

mitral valve changes - 70%
aortic valve changes - 25%
tricuspid valve changes - 10%
pulmonary valve changes are rare

Question 18

diagnosis

Answer 18

The Jones criteria

Question 19

What is required for a diagnosis of rheumatic fever?

Answer 19

evidence of recent streptococcal infection

plus 2 major criteria or 1 major and 2 minor criteria

Question 20

what counts as recent streptococcal infection?

Answer 20

scarlet fever
positive throat/wound swab
serological confirmed streptococcal infection - raised anti-streptolysin O titre of 200U/ml

Question 21

Jones criteria: major criteria

Answer 21

arthritis 
signs of carditis - murmur and echo 
chorea 
subcutaneous nodules 
erythema marginatum/annulare

Question 22

Jones criteria:minor criteria

Answer 22

fever
raised CRP/ESR
arthralgia - not a sign if arthritis already counted as a major sign
prolonged PR interval - not a sign if carditis already counted as a major sign

Question 23

when to consider rheumatic fever

Answer 23

any patient with chorea or carditis that doesn’t have obvious cause

Question 24

differential diagnoses

Answer 24

rheumatoid arthritis 
henoch-schonlein purpura 
reactive arthritis 
erythema nodosum 
infective endocarditis 
cardiomyopathy
myocarditis 
drug reactions (metoclopramide)

Question 25

investigations

Answer 25

throat swab
blood tests
ECG
CXR
Echocardiography

Question 26

throat swab

Answer 26

often long time since acute infection so won’t be diagnostic
frequently performed

Question 27

blood tests

Answer 27

anti-streptolysin antibody titre - ASOT = >200 suggests rheumatic fever
anti-DNase B
antibody levels usually rise for first month of illness and remain stable for following 3-6 months

Question 28

ECG

Answer 28

prolonged PR interval

Question 29

CXR

Answer 29

signs of heart failure

Question 30

echocardiography

Answer 30

to detect signs of carditis

can result in earlier diagnosis as may be detected before symptoms develop

Question 31

management aims

Answer 31

treat any streptococcal infection that is still present
reduce inflammation
treat complications - carditis which are often the most life-threatening

Question 32

treating infection

Answer 32

penicillin
oral or IM
if penicillin allergy use cephalosporins or erythromycin

Question 33

treating complications

Answer 33

arthritis
cardiac
neurological

Question 34

treating complications: arthritis

Answer 34

aspirin
NSAIDs
high doses
don’t reduce carditis

Question 35

treating complications: cardiac

Answer 35

treat heart failure - ACE inhibitors, digoxin and diuretics

mitral valve replacement

Question 36

treating complications: neurological

Answer 36

chorea is self-limiting typically

diazepam can reduce symptoms long-term

Question 37

recovery

Answer 37

80% will recover from an acute episode within 12 weeks

Question 38

prognosis

Answer 38

recurrent episode can occur - associated with re-infection with streptococcus
usually occurs within 5 years of original diagnosis

Question 39

rheumatic heart disease

Answer 39

occurs in up to 45% of patients in the long-term

patients need life-long cardiology follow up

Question 40

what can trigger recurrent rheumatic fever?

Answer 40

repeat streptococcal infection
pregnancy
use of combined oral contraceptive pill

Question 41

how to prevent rheumatic fever

Answer 41

secondary prophylaxis only

Question 42

secondary prophylaxis

Answer 42

long term antibiotic use recommended for all patients
should be continued for minimum of 5 years/ until age of 21 - whichever is longest
recommended for 10 years in patients with carditis
life-long prophylaxis in patients with severe valvular disease