Rheumatic Fever - intrinsic Flashcards
What is rheumatic fever?
Acute RF is:
- an autoimmune disease
- may occur following group A strep throat infection.
It can affect multiple systems, including:
- joints,
- heart,
- brain,
- skin.
Only the effects on the heart –> to permanent illness;
What is ‘chronic rheumatic heart disease?
Chronic changes to heart valves (as a complicaion of repeated bouts of acute rheumatic fever)
What is the prophylactic Tx for repeated bouts of acute rheumatic fever?
long-term penicillin secondary prophylaxis
without this:
- acute RF can recur,
- –> to cumulative damage to cardiac valvular tissue.
What is the cause of rhuematic fever?
- acute RF = autoimmune disease
- is the result of group A streptococcal infection –> an AI response in a susceptible host
Summarise the pathophysiology of rheumatic fever
The interaction between group A strep and a susceptible host
–> AI response directed against:
- cardiac
- synovial
- subcutaneous
- epidermal
- neuronal tissues.
It is believed that both cross-reactive Abs & cross-reactive T cells play a role in the disease.
- Molecular mimicry between group A strep pyogenes antigens and human host tissue is thought to be the basis of this cross-reactivity.
What are the risk factors for rheumatic fever?
- Poverty
- Overcrowded living quarters
- FHx of rheumatic fever
- D8/17 B cell antigen positivity
- HLA association
- Genetic susceptibility
- Indigenous populations; Aboriginal Australian, Asian, and Pacific Islanders
Summarise the epidemiology of rheumatic fever
- Primary episodes of acute RF:
- in children 5-14yr
- rare in people 30+yrs
- 2.4m+ children have rheumatic heart disease worldwide;
- 94% of these are in developing countries
- Worldwide there are 330,000+ new cases of acute RF annualy
- Recurrent episodes
- relatively common in adolescents & young adults
- but uncommon in those 35+yrs
What are the presenting symptoms of rheumatic fever?
- Fever
- Joint pain
- Swollen joints
- Recent sore throat or scarlet fever
-
Chest pain
- symptom of severe carditis
-
SOB
- symptom of severe carditis
-
Palpitations
- rheumatic carditis –> palpitations in associated w advanced heart block
- longstanding rheumatic heart disease + left atrial dilatation –> palpitations associated w AF
- signs of cardiac failure
Describe the joint pain (one of presenting symptoms of RF)
- extreme
- asymmetrical
- may be affected for a period of hours or a couple of days.
most commonly affected joints:
- knees
- ankles
- wrists
- elbows
- hips
What are the characteristics of arthritic pain vs arthralgia?
when accompanied by:
- tenderness
- warmth,
- restricted movement
–> indicates arthritis rather than arthrlagia
What are the signs of rheumatic fever O/E?
-
Carditis
- Mitral regurgitation is the most clinical manifestation of carditis and can be heard as a pan-systolic murmur loudest at the apex
- Pericardial rub
- Signs of cardiac failure
-
Arthritis
- Swollen joints
-
Chorea
- Jerky, uncoordinated choreiform movements
- Inability to maintain protrusion of the tongue
- Milkmaid’s grip
- Erythema marginatum
- Subcutaneous nodules
What is milkmaid’s grip?
- sign of chorea
- rhythmic squeezing when patient grasps the examiner’s hand
How long post-initial infection might rheumatic chorea occur?
It can occur up to 6 months after the initial infection
Describe the rash seen in rheumatic fever
Erythema marginatum
pink serpinginous rash with a well-defined edge
Describe the subcutaneous nodules seen in rheumatic fever
- firm, painless lumps
- 0.5-2cm in diameter
- found mainly over extensor surfaces / bony protuberances
- particularly on the extensor surfaces of the elbows, hands, feet, and over the occiput and upper back
What are the major and minor criteria for rheumatic fever?
