KAWASAKI'S SYNDROME
DEFINITION:
A vasculitic syndrome of large-medium vessels classically
characterized as an acute febrile illness associated with a systemic
vasculitis.
EPIDEMIOLOGY:
- incidence: 1-10/100,000
- age of onset:
- peak age is 1-3 years
- 80-85% <5 years; seldom >7 years; rare >11 years
- risk factors:
- M > F (1.5:1)
- endemic but increased in late winter to early spring
- seasonal epidemics every 2-3 years
- Orientals > Blacks > Whites
- secondary case contacts are rare (<1% to 2.1%)
- increased risk in a sibling (2.1% vs 0.19%) and in 54% of
these cases, the illness occurs within 10 days of onset in the
1st
- only 2-3% recurrence rate
PATHOGENESIS:
- expression of the syndrome seems to be dependent upon a
susceptible host being exposed to specific triggers:
- Orientals > Blacks > Whites
- ? HLA-Bw22
2. Specific Triggers
- bacterial - Strep. sanguis, Proprionibacterium acnes
- viral - retrovirus
CLINICAL FEATURES:
- from onset of symptoms til resolution of fever
- lasts from 5 to 21 days (mean = 11 days)
- earliest symptom
- remittent (39.5-40.5 C), high spiking, prolonged
- does not respond to antibiotic therapy
- resolves within 2-3 days of starting high dose ASA
2. Bilateral Conjunctival Exanthem
- begins shortly after onset of fever, lasts 1-2 weeks
- bulbar conjunctivitis with vascular dilation but no
exudate or palpebral involvement
3. Oral Mucosal Changes
- red, swollen, dry, fissured lips
- "strawberry tongue"
- diffuse erythema of oral & pharyngeal mucosa
4. Cervical Lymphadenopathy
- posterior cervical lymphadenopathy (50-75%)
- acute and nonpurulent; at least one node >1.5 cm
- tender, rarely red, fluctuant, torticollis
5. Peripheral Extremity Changes (acute stage)
- reddening of palms and soles
- indurative edema & tenderness of hands and feet
6. Polymorphous Rash
- begins within 5 days after onset of fever
- fine, erythematous, morbilliform generalized rash
- intense, desquamating rash in perineum (25-50%)
2. Subacute
- from resolution of fever to disappearance of all clinical
symptoms
- occurs by the 3rd to 4th week after onset
- lasts for 2 to 4 weeks
- membranous desquamation of fingertips & toetips
- noted at days 10-20 after onset of fever
- Beau's lines - deep transverse grooves across nails
3. Convalescent
- ends when the ESR & platelet count return to normal
- usually lasts 10 to 12 weeks
3. Complications
- extreme irritability and lethargy
- aseptic meningitis (25%) +\- meningismus
- hemiparesis or paralysis of extremities, ataxia
- pseudotumor cerebri
- increased intracranial pressure with papilledema
- cranial nerve and facial palsies; seizures
- mild sensorineuronal hearing loss
2. Respiratory Manifestations
- tympanitis
- rhinorrhea
- pneumonitis, pneumonia or pleural effusion
3. Cardiovascular Manifestations (20%)
- arrhythmias, gallop rhythm, CHF with shock
2. Pericarditis
- pericardial effusion
- cardiac tamponade (Beck's Triad - hypotension,
distended neck veins, diminished heart sounds)
3. Mitral/Aortic Regurgitation
- murmers, congestive heart failure (CHF)
2. Subacute Stage
- dilatation +/- aneurysms (20-40%)
- first detected at a mean of 10 days
- peak occurrence at 3-4 weeks after onset
- very rare to occur after 4 weeks
- 50% of aneurysms resolve by 18 months
- thrombosis and stenotic lesions -> angina, MI
- ruptured coronary aneurysm -> hemopericardium
2. Systemic Vasculitis (1-2%)
- cerebral vasculitis
- aneurysms of subclavian, axillary, brachial, and/or
hepatic arteries
- peripheral ischemia of hands & feet -> gangrene
4. Gastrointestinal Manifestations
- abdominal pain
- diarrhea
- hepatitis
- hydrops of gall bladder (5%)
- mild obstructive jaundice
- nausea/vomiting
- paralytic ileus
- RUQ mass or fullness
5. Genitourinary Manifestations
- priapism
- proteinuria
- hematuria with interstitial nephritis
- pyuria
- urethritis
6. Musculoskeletal Manifestatons
- polyarticular: knees, ankles, hands
- onset 1st week & lasts for 3 weeks
2. Subacute
- pauciarticular: weight-bearing joints
- onset 2nd-3rd week & lasts for 2-12 weeks
7. Others
- ocular - mild anterior uveitis (80%)
INVESTIGATIONS:
- increased ESR & alpha-1 antitrypsin, positive CRP
- elevated at onset of fever and persists for 6-10 weeks
2. CBC
- anemia - mild-moderate normochromic normocytic
- resolves during convalescent phase
- thrombocytosis - normal during 1st week, increases during
2nd week, peaks at 3 weeks
- leukocytosis - mild-moderate (12-18) but as high as 30
- predominance of neutrophils
- left shift with increase in bands
3. Others
- hypoalbuminemia (as low as 20 g/L)
- normal immunoglobulins, C3, C4, elevated IgE
- positive circulating immune complexes
- negative cultures, serologic assays, ANA, Rf
- liver function tests - mildly to moderately elevated
2. CSF
- mononuclear pleocytosis (25-100 WBC)
- normal or slightly elevated protein
- normal glucose
3. EKG
- arrhythmias - 1st & 2nd degree heart block, PVC, prolonged
QT interval, non-specific ST-T segment changes
4. Urinalysis
- pyuria, microscopic hematuria
- minimal proteinuria
5. Imaging Studies
- at 3-4 weeks then again at 6-8 weeks after onset
2. Coronary Angiograms
- to detect impaired perfusion from coronary stenosis or
thrombosis
MANAGEMENT:
- hydration therapy if dehydrated
- pain control
2. Medications
- 2 gm/kg IV in one infusion
2. High Dose ASA
- 100 mg/kg/day po qid until afebrile for 24-36 hours
- institution of IVGG and ASA within 10 days of fever
onset reduces the incidence of coronary artery lesions from
18% to 4%
2. Subacute Phase
- 3-5 mg/kg/day po od
- begin after afebrile for 24-36 hours
- no cardiac involvement
- continue until ESR and platelet count are normal (6-8
weeks) or 2D Echo normal at 8 weeks
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