ACUTE RHEUMATIC FEVER (Harrison)

Acute Rheumatic Fever
· Multisystem disease resulting from an autoimmune reaction to infection with
group A streptococcus.
· Cardiac valvular damage [rheumatic heart disease (RHD)
.
Epidemiology
· children aged 5–14 years
· RHD more commonly affects females, sometimes up to twice as frequently as
males.
Pathogenesis
.
Cross-reactive epitopes are present in the streptococcal M protein and the Nacetylglucosamine
of group A streptococcal carbohydrate and are immunologically
similar to molecules in human myosin, tropomyosin, keratin, actin, laminin,
vimentin, and N-acetylglucosamine..
Clinical Features
· latent period - 3 weeks (1–5 weeks
· The most common clinical presentation of ARF is polyarthritis and fever.
Polyarthritis ---- 60–75% of cases and
carditis ----- 50–60%.
chorea -------- <2% to 30%.
Erythema marginatum and subcutaneous nodules <5% of cases.
Heart Involvement
Valvular damage is the hallmark of rheumatic carditis. mitral valve > aortic valve;
Early valvular damage leads to regurgitation. Over ensuing years, usually as a result of
recurrent episodes, leaflet thickening, scarring, calcification, and valvular stenosis may
develop Myocardial inflammation may affect electrical conduction pathways, leading
to P-R interval prolongation (first-degree AV block or rarely higher-level block) and
softening of the first heart sound.
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Joint Involvement
· inflammation, with hot, swollen, red and/or tender joints,
· and involvement of more than one joint (i.e., polyarthritis)
· migratory,
· large joints—most commonly the knees, ankles, hips, and elbows
· —and is asymmetric.
· The pain is severe and usually disabling until anti-inflammatory medication is
commenced.
· highly responsive to salicylates and other nonsteroidal anti-inflammatory drugs
(NSAIDs).
Indeed, joint involvement that persists more than 1 or 2 days after starting salicylates is
unlikely to be due to ARF. Conversely, if salicylates are commenced early in the illness,
before fever and migratory polyarthritis have become manifest, it may be difficult to
make a diagnosis of ARF. For this reason, salicylates and other NSAIDs should be
withheld—and pain managed with acetaminophen or codeine—until the diagnosis is
confirmed.
Sydenham's Chorea
· mainly in females.
· The choreiform movements affect particularly the head (causing characteristic
darting movements of the tongue) and the upper limbs
· Chorea eventually resolves completely, usually within 6 weeks.
Skin Manifestations
· erythema marginatum, which begins as pink macules that clear centrally,
leaving a serpiginous, spreading edge. The rash is evanescent, appearing and
disappearing before the examiner's eyes. It occurs usually on the trunk,
sometimes on the limbs, but almost never on the face.
· Subcutaneous nodules occur as painless, small (0.5–2 cm), mobile lumps
beneath the skin overlying bony prominences, particularly of the hands, feet,
elbows, occiput, and occasionally the vertebrae. They are a delayed
manifestation, appearing 2–3 weeks after the onset of disease, last for just a few
days up to 3 weeks, and are commonly associated with carditis.
Other Features
1. Fever
2. . Although high-grade fever ( 39°C) is the rule, lower grade temperature
elevations are not uncommon.
3. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are often
dramatically elevated. Occasionally the peripheral leukocyte count is mildly
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elevated.
4. Evidence of a Preceding Group a Streptococcal Infection
5. preceding group A streptococcal infection is essential in making the diagnosis
of ARF. The most common serologic tests are the anti-streptolysin O (ASO)
and anti-DNase B (ADB) titers. Other Post-Streptococcal Syndromes that May
Be Confused with Rheumatic Fever
Post-streptococcal reactive arthritis (PSRA) is differentiated from ARF on the basis
of:
(1) small-joint involvement that is often symmetric;
(2) a short latent period following streptococcal infection (usually <1 week);
(3) occasional causation by nongroup A -hemolytic streptococcal infection;
(4) slower responsiveness to salicylates; and
(5) the absence of other features of ARF, particularly carditis.
Pediatric autoimmune neuropsychiatric disorders associated with streptococcal
infection (PANDAS) is a term that links a range of tic disorders and obsessivecompulsive
symptoms with group A streptococcal infections. People with PANDAS are
said not to be at risk of carditis, unlike patients with Sydenham's chorea. The diagnoses
of PANDAS and PSRA should rarely be made in populations with a high incidence of
ARF.
Confirming the Diagnosis
Diagnostic Categories Criteria
Primary episode of rheumatic fevera · Two major plus evidence of preceding
group A streptococcal infection
· or one major and two minor
manifestations plus evidence of
preceding group A streptococcal
infection
Recurrent attack of rheumatic fever
in a patient without established
rheumatic heart disease
· Two major plus evidence of preceding
group A streptococcal infection
· or one major and two minor
manifestations plus evidence of
preceding group A streptococcal
infection
Major manifestations Joints (polyarthritis)
Obvious Carditis
Erythema marginatum
Nodules (Subcutaneous )
Sydneham’s Chorea
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Minor manifestations Prolonged P-R interval
Elevated erythrocyte sedimentation rate or
leukocyte counte
Arthralgia(poly)
CRP Raised
Elevated temperature
Supporting evidence of a preceding
streptococcal infection within the last
45 days
Elevated or rising anti-streptolysin O or other
streptococcal antibody, or
A positive throat culture, or
Rapid antigen test for group A streptococcus,
or
Recent scarlet fevere
Treatment: Acute Rheumatic Fever
Table 322-2 Recommended Tests in Cases of Possible Acute Rheumatic Fever
Recommended for all cases
· White blood cell count
· Erythrocyte sedimentation rate
· C-reactive protein
· Blood cultures if febrile
· Electrocardiogram (repeat in 2 weeks and 2 months if prolonged P-R interval
or other rhythm abnormality)
· Chest x-ray if clinical or echocardiographic evidence of carditis
· Echocardiogram (consider repeating after 1 month if negative)
· Throat swab (preferably before giving antibiotics)–culture for group A
streptococcus
· Anti-streptococcal serology: both anti-streptolysin O and anti-DNase B titres,
if available (repeat 10–14 days later if 1st test not confirmatory)
Tests for alternative diagnoses, depending on clinical features
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· Repeated blood cultures if possible endocarditis
· Joint aspirate (microscopy and culture) for possible septic arthritis
· Copper, ceruloplasmin, anti-nuclear antibody, drug screen for choreiform
movements
· Serology and auto-immune markers for arboviral, auto-immune or reactive
arthritis
treatment of ARF is symptomatic.
1. Antibiotics
· Penicillin is the drug of choice and can be given orally
· [as phenoxymethyl penicillin, 500 mg (250 mg for children 27 kg) PO twice
daily,
· or amoxicillin 50 mg/kg (max 1 g) daily, for 10 days]
· or as a single dose of 1.2 million units (600,000 units for children 27 kg) IM
benzathine penicillin G.
2. Salicylates and NSAIDs
for the treatment of arthritis, arthralgia, and fever, once the diagnosis is confirmed.
They are of no proven value in the treatment of carditis or chorea.
Aspirin is the drug of choice.
An initial dose of 80–100 mg/kg per day in children (4–8 g/d in adults) in 4–5 divided
doses is often needed for the first few days up to 2 weeks. the dose can be reduced to
60–70 mg/kg per day for a further 2–4 weeks. Although less well studied, naproxen at a
dose of 10–20 mg/kg per day has been reported to lead to good symptomatic response.
3. Congestive Heart Failure
Glucocorticoids
If used, prednisone or prednisolone are recommended at doses of 1–2 mg/kg per day
(maximum, 80 mg). Glucocorticoids are often only required for a few days or up to a
maximum of 3 weeks.
4. Management of Heart Failure
See Chap. 234.
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5. Bed Rest
When arthritis and arthralgia are present, and for patients with heart failure..
6. Chorea
· Carbamazepine
· or sodium valproate
7. Intravenous Immunoglobulin (Ivig)
may lead to more rapid resolution of chorea
not recommended except in cases of severe chorea refractory to other treatments.
Prognosis
Untreated, ARF lasts on average 12 weeks. With treatment, patients are usually
discharged from hospital within 1–2 weeks. Inflammatory markers should be monitored
every 1–2 weeks until they have normalized (usually within 4–6 weeks), and an
echocardiogram should be performed after 1 month to determine if there has been
progression of carditis. Cases with more severe carditis need close clinical and
echocardiographic monitoring in the longer term.
Secondary Prevention
· The best antibiotic for secondary prophylaxis is benzathine penicillin G (1.2
million units, or 600,000 units if 27 kg) delivered every 4 weeks. It can be
given every 3 weeks, or even every 2 weeks, to persons considered to be at
particularly high risk, although in settings where good compliance with 4-
weekly dosing can be achieved, more frequent dosing is rarely needed.
· Oral penicillin V (250 mg) can be given twice-daily instead but is somewhat
less effective than benzathine penicillin G.
· Penicillin allergic patients can receive erythromycin (250 mg) twice daily.
Category of Patient Duration of Prophylaxis
Rheumatic fever without carditis For 5 years after the last attack or 21 years
of age (whichever is longer)
Rheumatic fever with carditis but no
residual valvular disease
For 10 years after the last attack, or 21
years of age (whichever is longer)
Rheumatic fever with persistent valvular
disease, evident clinically or on
echocardiography
For 10 years after the last attack, or 40
years of age (whichever is longer).
Sometimes lifelong prophylaxis.
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· The McGraw-Hill Companies.
· Dr.Shami Bhagat (SKIMS)
· All rights reserved.