Rheumatic fever

Question 1

What is acute rheumatic fever?

Answer 1

Systemic multiorgan illness

Question 2

When does acute rheumatic fever tend to occur?

Answer 2

2-4weeks after pharyngitis

Question 3

Why does acute rheumatic fever occur?

Answer 3

Cross reactivity to group A beta haemolytic streptococcus (strep pyogenes)

B cells stimulated to produce anti-M protein antibodies against the infection that cross react with other tissues (heart, brain, joints and skin)

Question 4

How many children worldwide are affected by rheumatic fever?

Answer 4

4 million

Question 5

Where is the incidence of rheumatic fever highest?

Answer 5

Less developed tropical countries - overcrowding

Question 6

Which sex experiences more rheumatic fever?

Answer 6

Female

Question 7

What gram stain is Streptococcus pyogenes?

Answer 7

Gram positive cocci

Question 8

Name the two cytolytic toxins that streptococcus pyogenes produces

Answer 8

Streptolysin O and S

Question 9

What proteins do rheumatogenic strains contain in their cell walls?

Answer 9

M proteins

Question 10

Which criteria is used to diagnose rheumatic fever?

Answer 10

Revised Jones diagnostic criteria

Question 11

What is the clue in the history that someone may be presenting with rheumatic fever?

Answer 11

Recent sore throat or scarlet fever

Question 12

What clinical sign may be present in severe acute rheumatic fever

Answer 12

Heart murmur

Question 13

Which valve is most often affected in rheumatic fever?

Answer 13

Mitral

Question 14

Describe the diagnostic requirements of rheumatic fever

Answer 14

Positive throat culture for group A beta haemolytic streptococcus or elevated anti-Streptolysin O (ASO) or anti-deoxyribonuclease B titre

Question 15

Describe the diagnostic requirements of rheumatic fever

Answer 15

Positive throat culture for group A beta haemolytic streptococcus or elevated anti-Streptolysin O (ASO) or anti-deoxyribonuclease B titre

AND

2 major criteria or 1 major and 2 minor criteria present for initial ARF

Question 16

List the major criteria for acute rheumatic fever

Answer 16

SPECS
Sydenham's chorea 
Polyarthritis 
Erythema marginatum 
Carditis
Subcutaneous nodules

Question 17

List the minor criteria for initial ARF diagnosis

Answer 17

CRP/ESR
Arthralgia
Pyrexia/fever
ECG

Question 18

What is seen on ECG of someone with ARF

Answer 18

Prolonged PR interval

Question 19

List the differential diagnosis for acute rheumatic fever

Answer 19

Septic arthritis
Reactive arthropathy
Infective endocarditis
Myocarditis

Question 20

What investigations are done for rheumatic fever?

Answer 20

Bloods - CRP, ESR, FBC (WCC)
Blood cultures - exclude sepsis
Rapid antigen detection test
Throat culture
Anti-streptococcal serology - ASO and anti-DNASE B titres 
ECG - prolonged PR interval 
CXR - if carditis suspected, heart failure may be seen due to valvular damage
Echo

Question 21

What is the initial management of rheumatic fever?

Answer 21

Antibiotics - benzathine benzylpenicillin, phenoxymethylpenicillin, amoxicillin. In confirmed penicillin allergy, use alternatives such as cephalosporins, macrolides and clindamycin

Aspirin and NSAIDs - naproxen and ibuprofen

Assess for emergency valve replacement

In severe carditis - glucocorticosteroids and diuretics

Question 22

What is the secondary prophylaxis of rheumatic fever?

Answer 22

IM benzathine benzylpenicillin every 3-4weeks
Oral phenoxymethylpenicillin BD
Oral sulfadiazine daily or oral azithromycin in penicillin allergy

Question 23

What percentage of the population get chronic rheumatic heart disease and valvular damage from rheumatic fever?

Answer 23

2%

Question 24

How long should ARF resolve with treatment?

Answer 24

2 weeks but cardiac inflammation may take months to fully resolve and relapse is common