Rheumatic Fever Flashcards
What is rheumatic fever?
- Acute rheumatic fever is a systemic disease of childhood, often recurrent that follows group A beta hemolytic streptococcal infection
- It is a delayed non-suppurative sequelae to URTI with GABH streptococci.
- It is a diffuse inflammatory disease of connective tissue, primarily involving heart, blood vessels, joints, subcutaneous tissue and CNS
Epidemiology?
- Ages 5-15 yrs are most susceptible
- Rare <3 yrs
- Girls>boys
- Common in 3rd world countries
- Environmental factors
e.g. overcrowding, poor sanitation, poverty - Incidence more during fall, winter & early spring
Organism causes?
When do you see the clinical features - latent period?
group A beta-streptococcus
- There is a latent period of ~3 weeks (1–5 weeks) between the group A streptococcal infection and the appearance of the clinical features of RF
Cases of rheumatic fever are often associated with?
Name the URTI?
All cases associated with recent infection (e.g. pharyngitis)
- Antibody and cellular immune response cross-reacts with human connective tissue
Pathogenesis of rheumatic fever?
- Rheumatic fever affect the peri-arteriolar connective tissue
- It is believed to be caused by antibodycross-reactivity
- This cross-reactivity is a Type II hypersensitivity reaction and is termedmolecular mimicry
- Delayed immune response to infection with group. A beta hemolytic streptococci. - After a latent period of 1-3 weeks, antibody induced immunological damage occur to heart valves, joints, subcutaneous tissue & basal ganglia of brain
Group A beta strep strains that produces rheumatic fever?
M types l, 3, 5, 6,18 & 24
Pharyngitis?
produced by GABHS can lead to:
1. acute rheumatic fever
2. rheumatic heart disease
3. post streptococcal glomerulonephritis
Skin infection?
produced by GABHS leads to post streptococcal glomerulonephritis only
- It will not result in Rheumatic Fever or carditis
Clinical manifestation?
Diagnosis of RHD?
Jones criteria for the diagnosis of acute rheumatic fever
- 2 major criteria
- 1 major & 2 minor criteria along with the absolute requirement
Note: There are 5 major and 4 minor criteria & an absolute requirement for evidence (microbiologic or serologic) of recent GABHS infection
Jones major criteria?
JONES
J - joint involvement
O - myocarditis
N - nodules, subcutaneous
E - erythema marginatum
S - sydenham chorea
Jones minor criteria?
CAFE PAL
C - CRP increased
A - arthralgia
F - fever
E - elevated ESR
P - prolonged PR interval
A - anamnesis of rheumatism
L - leukocytosis
Absolute diagnostic evidence?
- throat cultures growing GABHS
- elevated anti-streptolysin O titers
Describe arthritis?
- Migratory polyarthritis, involving major joints
- Commonly involved joints-knee, ankle, elbow & wrist
- Occur in 80%, involved joints are exquisitely tender
- In children below 5 yrs arthritis usually mild but carditis more prominent
- Arthritis do not progress to chronic disease
Describe carditis?
- Manifest as pancarditis
e.g. endocarditis, myocarditis and pericarditis - occur in 40-50% of cases - Carditis is the only manifestation of rheumatic fever that leaves a sequelae & permanent damage to the organ
Phases of carditis?
- Acute phase - valvulitis
- Chronic phase - fibrosis, calcification & stenosis of heart valves
Features of carditis?
- Consists of either isolated mitral valvular disease or combined aortic & mitral valvular disease
- Valvular insufficiency: characteristic of both acute & convalescent stages of acute rheumatic fever
Sydenhams chorea?
- The choreiform movements affect particularly the head and the upper limbs
- They may be generalized or restricted to one side of the body (hemi-chorea)
- Clinically manifest as-clumsiness, deterioration of handwriting, emotional lability or grimacing of face
Epidemiology of Sydenhams chorea?
occurs in children, rare in adults
Causes of Sydenhams chorea?
likely due to molecular mimicry, with autoantibodies reacting with brain ganglioside in the basal ganglia
- Chorea eventually resolves completely, usually within 6 weeks
Erythema marginatum?
- Unique, transient lesions of 1-2 inches in size
- It consists of erythematous, serpiginous, macular lesions with pale centers that are not pruritic
- Pale center with red irregular margin
- More on trunks & limbs & not on the face & it can be accentuated by warming the skin
Erythema marginatum is associated with?
Often associated with chronic carditis
Subcutaneous nodules?
- Painless, pea-sized, palpable nodules
- Mainly over extensor surfaces of joints, spine, scapulae & scalp
Subcutaneous nodules are associated with?
- Associated with strong seropositivity
- Always associated with severe carditis
Minor features of rheumatic fever?
- Fever – Low grade
- Arthralgia
- Pallor
- Anorexia
- Loss of weight
Labaratory findings?
- High ESR
- Anemia, leucocytosis
- Elevated C-reactive protein
- ASO titre >200.
- Peak value attained at 3 weeks, then comes down to normal by 6 weeks - Anti-DNAse B test
- Throat culture-GABH streptococci
- ECG - prolonged PR interval
- Echo
Echo results?
- valve edema
- mitral regurgitation
- LA & LV dilatation
- pericardial effusion
- decreased contractility
Ddx for RHD?
Patients with infective endocarditis
- present with both joint and cardiac manifestations
Differentiating between infective endocarditis vs RHD?
- blood cultures
- the presence of associated findings
- hematuria, splenomegaly, splinter hemorrhages
Treatment of rheumatic fever?
- bed rest
- antibiotic therapy
- anti-inflammatory therapy
Antibiotic therapy?
- 10 days of orally administered penicillin or erythromycin
or - a single intramuscular injection of benzathine penicillin to eradicate GABHS from the upper respiratory tract
- Afterwards, the patient should be started on long-term antibiotic prophylaxis
Anti-inflammatory therapy?
- salicylates, corticosteroids
- should be withheld if arthralgia or atypical arthritis is the only clinical manifestation of presumed acute rheumatic fever - Acetaminophen can be used
Treatment of Patients with typical migratory polyarthritis & with carditis without cardiomegaly or congestive heart failure?
Treatment with oral salicylates
- 100mg/kg/day in 4 divided doses PO for 3-5 days
- followed by 75mg/kg/day in 4 divided doses PO for 4-8wk
Treatment of Patients with carditis & cardiomegaly or congestive heart failure?
- treatment with corticosteroids
- Prednisone 2mg/kg/day in 4 divided doses for 2-6wk followed by a tapering of the dose that reduces the dose by 5mg/24hr every 2-3 days
- At the beginning of the tapering of the prednisone dose, aspirin should be started at 75mg/kg/day in 4 divided doses to complete 12wk of therapy
Supportive therapy for patients with moderate to severe carditis?
- digoxin
- fluid & salt restriction
- diuretics & oxygen
Note: The cardiac toxicity of digoxin is enhanced with myocarditis
Treatment of Sydenham Chorea?
- Anti-inflammatory agents are usually not indicated
- Sedatives: phenobarbital (16-32mg every 6-8hr PO) is the drug of choice
- If phenobarbital is ineffective, then haloperidol (0.01-0.03mg/kg/24hr divided bid PO) or chlorpromazine (0.5mg/kg every 4-6hr PO) should be initiated
- Long-term antibiotic prophylaxis
Primary prevention in rheumatic fever?
10 days course of penicillin therapy
- about 30% of patients with acute rheumatic fever do not recall a preceding episode of pharyngitis
Secondary prevention of rheumatic fever?
Secondary prevention is directed at preventing acute GABHS pharyngitis in patients at substantial risk of recurrent acute rheumatic fever
Who should receive prophylaxis in secondary prevention?
Patients with documented history of rheumatic fever, including those with isolated chorea & those without evidence of rheumatic heart disease MUST receive prophylaxis
Secondary prevention in rheumatic fever without carditis?
How long to give Prophylaxis treatment?
at least for 5 year or until age 21 year, whichever is longer
Secondary prevention in rheumatic fever with carditis but without residual heart disease (no valvular disease)?
at least for 10 years or well into adulthood, whichever is longer
Secondary prevention in rheumatic fever with carditis and residual heart disease (persistent valvular disease)?
How long to give prophylactic treatment for?
at least 10 years since last episode and at least until age 40 years: sometimes lifelong
Drugs used in secondary prevention as prophylaxis?
- penicilin G benzathine
- 600,000U for children, ≤27 kg
-1.2 million U for children >27 kg, every 3wk
- intramuscular - penicilin V
- 250mg twice a day
- oral - sulfadiazine or sulfisoxazole
- 0.5g, once a day for patients ≤60lb; 1.0g, once a day for patients >60lb
- oral
Alternative for penicillin allergic patients?
- Cephalexin 500mg iv stat
- Azithromycin 500mg iv stat
- Clarithromycin 500mg iv stat or
- Clindamycin 900mg iv stat
