Acute Rheumatic Fever and Rheumatic Heart Disease

Question 1

who gets acute rhuematic fever

Answer 1

5-14yo
females diagnosed more frequently
ethnicity - indigenous australians, maori, pacific islanders, migrants from low/middle income countries
high risk of recurrance

Question 2

when does ARF develop

Answer 2

develops 1-5 weeks following infection with strep pyogenes

Question 3

initial strep infection may present as

Answer 3

Initial strep pyogenes infection usually presents as pharyngitis (strep throat) but may present as an infection of the skin (cellulitis)

Question 4

why does ARF develop following strep infection

Answer 4

Rheumatic fever develops in susceptible hosts (2% of the population) due to a hypersensitivity reaction against the bacteria (type 2 hypersensitivity)

Question 5

what kind of bacteria is strep pyogenes

Answer 5

group A strep
Gram positive coccus, aerobic/facultative anaeroabe
Catalase negative
Lancefeild group A
Beta-hemolytic
Bacitracin susceptible
100 serotypes defined by surface M protein

Question 6

clinical syndromes of strep A infection

Answer 6

noninvasive: skin, pharynngitis
invasive: bacteraemia, septicaemia, necrotising fascitis, bone/joint, empyema, meningitis
toxin-mediated: toxic shock, scarlett fever
immune-mediated: ARF, RHD, glomerulonephritis

Question 7

types of evidence of recent group A strep infection

Answer 7

positive throat swab
repid streptococcal antigen test
raised antistreptolysin O titre or Anti-DNase B titre
recent episode of scarlet fever

Question 8

when to use culture of group A strep

Answer 8

historic gold standard
most useful for acute infections, especially invasive GAS
less useful for post-infectious complications

Question 9

serology for group A strep is most useful for

Answer 9

most useful for the diagnosis of post-infectious complications

Question 10

Jones’ criteria

Answer 10

evidence of recent group A strep infection (culture or serology)
AND
two major criteria
OR
one major and two minor criteria

Question 11

major manifestations of acute rhuematic fever

Answer 11

polyarthritis
carditis
subcutaneous nodules
erythema marginatum
sydenham’s chorea

Question 12

acronym for Jones’ criteria

Answer 12

J = joints
<3 = heart
N = nodules
E = erythema marginatum
S = sydenham’s chorea

Question 13

arthritis in acute rheumatic fever

Answer 13

most common presentation
classically: asymmetric, migratory, large joints
very responsive to NSAIDs

Question 14

whats the difference between arthritis and arthralgia

Answer 14

arthrtis requres evidence of inflammation
arthritis: swollen, hot joint, with pain in movement
arthralgia: pain on joint movement, no joint swelling or heat

Question 15

carditis in acute rheumatic fever

Answer 15

2nd most common clinical feature
predominantly inflammation of the endocardium (as opposed to myocardium/pericardium) - especially left side valvulitis = mitral valve regurgitation

Question 16

clinical features of carditis

Answer 16

often subclinical
clinical features may include:
- cardiac murmur
- cardiac enlargement
- cardiac decompensation
- pericardial friction rub or effusion

Question 17

most common valve affected in carditis

Answer 17

mitral valve

Question 18

investigations for carditis

Answer 18

ECG: prolonged PR interval
Echo: valvulitis

Question 19

role of echocardiogram in valvulitis

Answer 19

define the severity of mitral aortic and/or tricuspid regurgitation
define the severity of mixed valve disease (mixed stenotic and regurgitant)
identify subclinical evidence of rheumatic valve damage
visualse valvular anatomy and define meechanism of reegurgitation (prolapse, flail leaflet, annular dilatation etc)

Question 20

role of echocardiogra, in cardiac function

Answer 20

assess left ventricular size and function

Question 21

chorea as a clinical feature of acute rheumatic fever

Answer 21

late presenting sign
if other causes of chorea are excluded, chorea is diagnostic for ARF
can occur after a period of latency
disappears during sleep

Question 22

clinical signs of chorea

Answer 22

milkmaids hands - rhythmic squeezing of examiners hands
spooning - flexion of the wrists and extension of the fingeer when the hands are extended
pronator sign - turning outward of the arms and palms when help above the head
inability to maintain protrusion of the tongue

Question 23

subcutenous nodules

Answer 23

rare
highly specific for ARF
strong association with carditis
crops of small, round, painless nodules
usually on extensor surfaces - over the lebows, wrists, knees, ankles, achillies tendon, occiput and posterior spinal processes of the vertebrae

Question 24

erythema marginatum

Answer 24

extremely rare
diifficult to see in dark skinned populations
occurs as circular patterns of bright ppink macules or pappules on the trunk and proximal extremities, face usually spared
called geogrphical rash - looks like borders on a map with pale centre

Question 25

is erythema marginatum painful

Answer 25

not pruritic or painful

Question 26

time course of erythema marginatum

Answer 26

evanescent - waxes and wanes during the course of a day can recur for weeks/months

Question 27

are NSAIDs effective for erythema marginatum

Answer 27

NSAIDs and steroids not effective

Question 28

minor JONES criteria

Answer 28

polyarthralgia prolonged PR interval on ECG Hx of rheumatic fever fever raised inflammatory markers - CRP, ESR, leuks

Question 29

investigations for acute rheumatic fever

Answer 29

bedside: vitals and ECG- for prolonged PR interval Labs: FBC - raised WCC ESR, CRP - raised troponin - raised in carditis strep serology (ASOT, antiDNaseB) dependant on context: throat swab, skin sore swab, blood culture, synovial fluid aspirate rheumatoid and anti-CCP to rule out other diagnoses imaging: Echo to aid carditis diagnosis chest x-ray to rule out heart failure

Question 30

ddx for joint symptoms

Answer 30

juvenile idiopathic arthritis reactive arthritis HSP- henoch-schonlein purpura

Question 31

cardiac disease might otherwise be explained by

Answer 31

cardiomyopathy kawasaki disease infective endocarditis

Question 32

chorea may be otherwise explained by

Answer 32

wilson's disease adverse drug reactions huntington's disease (very rare in children)

Question 33

skin changes may be otherwise explained by

Answer 33

advserse drug reactions Lyme disease/erythema migrans erythema multiforme

Question 34

treatment for strep throat infection in high risk groups

Answer 34

bed rest strongly recommended especilly if myocarditis is present IM benzaathine benzylpenecillin G (BPG) is the antibiotic of choice, single dose

Question 35

treatment for arthritis

Answer 35

paracetamol, tramadol if diagnosis unclear NSAID if diagnosis confirmed immobilise

Question 36

carditis treatment

Answer 36

diuretics, ACEI pericardiocentesis to remove fluid collections around the heart (in presence of pericardial effusions) may be needed treat heart failure as required

Question 37

chorea treatment

Answer 37

dizepam, haloperidol, carbamazepine, valpproate if functional impairment but this symptom is self limiting

Question 38

complications of acute rheumatic fever

Answer 38

carditis heart fialure pericardial effusions valvular disease (especially the mitral valve) atrial fibrilltion pulmonary hypertension thromboembolic events refractory chorea (plasmapheresis may be required

Question 39

what causes rheumatic heart disease

Answer 39

similarities between the streptococcal bacteria and human heart valve tissue lead to autoimmune damage to the hert valves

Question 40

prevelence of rheumatic heart disease

Answer 40

peak prevalence in thrid or forth deecades more common in females mitral valve most commonly affected echo: gold standard for diagnosis

Question 41

symptoms of rheumatic heart disease

Answer 41

may be asymtpomatic dyspnoea: on exertion, orthopnoea, paroxysmal nocturnal dyspnoea fatigue, weakness angina syncope

Question 42

signs of rheumatic heart disease

Answer 42

heart murmur heart failure arrythmia

Question 43

natural history of rheumatic heart disease

Answer 43

Question 44

primordial prevention of rheumatic heart disease

Answer 44

disease of poverty overcrowding washing facilities for people, clothing, bedding

Question 45

primary prevention of rheumatic heart disease

Answer 45

regognise strep throat and skin infections and treat with antibiotics

Question 46

secondary prevention of rheumatic heart disease

Answer 46

consistent and regular administration of antibiotics to people who have had ARF or RHD, to prevent future GAS infections, ARF recurrence, and thus limit RHD development/progression use long-acting intramuscular benzathine penicillin G (BPG) duration depends on: ARF classification, presence of RHD (and its classification), age