Acute rheumatic fever

Question 1

What is acute rheumatic fever? What is the causative agent?

Answer 1

Inflammatory autoimmune disease secondary to infection from streptococcus pyogenes from previous pharyngitis or tonsilitis

Question 2

How is the autoimmune response seen in acute rheumatic fever created?

Answer 2

Streptococcus pyogenes has surface “M” proteins. These M proteins have a region which is very similar to a region in heart myosin proteins (Shared epitope)

Antibodies created to react to this region in the M proteins also can react to the similar region in the heart myosin proteins, resulting in the immune system targeting myosin as well, causing carditis (molecular mimicry)

Question 3

What are the symptoms of Pharyngitis/Tonsilitis?

Answer 3

• Red and/or swollen tonsils with yellow patches
• Sore throat
• Headache
• Fever

Question 4

What are the symptoms of carditis?

What can it develop into?

What can multiple untreated episodes of acute rheumatic fever lead to?

Answer 4

• Shortness of breath
• Heart murmur

Carditis can develop into congestive heart failure

Multiple untreated episodes of acute rheumatic fever can result in rheumatic heart disease

Question 5

What are the two pieces of evidence required for diagnosis of acute rheumatic fever?

Answer 5

• Two major criteria or one major and two minor criteria
• Evidence of previous Streptoccocus pyogenes infection

Question 6

What are the major criteria/symptoms for diagnosing acute rheumatic fever?

Answer 6

Migratory polyarthritis
- Joint inflammation and pain that can shift location
- Monoarthritis with history of NSAID use

Carditis
- Inflammation and damage of heart tissue
- Echocardiographic evidence is acceptable

Nodules
- Subcutaneous and painless

Erythema marginatum rash
- Looks like octopus attack

Syndham’s chorea (St Vitus Dance)
- Uncontrolled muscle movement due to autoimmune neuron damage

Question 7

What are the minor criteria for diagnosing acute rheumatic fever?

Answer 7

Fever
Raised C reactive protein
Prolonged PR interval without carditis

Question 8

What is the treatment for acute rheumatic fever?

Answer 8

Reduce inflammation
- Aspirin
- NSAIDS

Eradicate streptococcus pyogenes infection
- Amoxicillin for 10 days
- Erythromycin or Clindamycin if allergic to penicillin

Prophylactic antibiotics to prevent reinfection for following years
- Oral amoxicillin
- Benzathine penicillin (Intramuscular)