Symptoms and Treatment of Kawasaki Disease
Kawasaki disease is diagnosed by the presence of fever lasting at least 5 days plus 4 out of 5 principal clinical features: bilateral nonexudative conjunctival injection, oral mucosal changes, extremity changes, polymorphous rash, and cervical lymphadenopathy. 1
Principal Clinical Features
1. Fever
- High-spiking fever (>39°C/102.2°F) that typically persists for 1-3 weeks if untreated
- Fever usually resolves within 36 hours after IVIG treatment 1
- The first calendar day of fever is considered illness day 1
2. Oral Mucosal Changes
- Erythema and cracking of lips
- Strawberry tongue
- Diffuse erythema of oral and pharyngeal mucosa
- No ulcerations or exudates (would suggest alternative diagnosis) 1
3. Bilateral Conjunctival Injection
- Nonexudative (no pus)
- Typically bulbar with limbus sparing
- Often begins shortly after fever onset
- Anterior uveitis may be observed by slit-lamp examination 1
4. Polymorphous Rash
- Most commonly maculopapular, primarily involving trunk and extremities
- May appear as erythroderma, erythema multiforme-like, urticarial, or micropustular
- Accentuation in the groin with early desquamation is characteristic
- Bullous, vesicular, or petechial rashes are NOT consistent with Kawasaki disease 1
5. Changes in Extremities
- Acute phase: Erythema and edema of hands and feet with sharp demarcation at wrists/ankles
- Convalescent phase: Periungual desquamation (peeling) starting 2-3 weeks after onset 1
6. Cervical Lymphadenopathy
- Least common of the principal features
- Usually unilateral
- At least 1.5 cm in diameter
- Confined to anterior cervical triangle 1
Other Clinical and Laboratory Findings
Cardiovascular
- Coronary artery aneurysms develop in 15-25% of untreated children 1
- Gallop rhythm or distant heart sounds
- ECG changes (arrhythmias, abnormal Q waves, prolonged PR/QT intervals)
- Cardiomegaly on chest x-ray 1
Gastrointestinal
- Diarrhea, vomiting, abdominal pain
- Hydrops of gallbladder
- Mild jaundice
- Elevated liver enzymes 1
Laboratory Findings
- Elevated ESR and CRP
- Leukocytosis with left shift
- Hypoalbuminemia
- Mild anemia
- Thrombocytosis (typically in second week of illness)
- Sterile pyuria 1
Diagnosis
Classic Kawasaki Disease
- Fever for ≥5 days plus ≥4 of the 5 principal clinical features
- In the presence of ≥4 features, particularly with hand/foot changes, diagnosis can be made with only 4 days of fever 1
Incomplete (Atypical) Kawasaki Disease
- Fever for ≥5 days plus 2-3 principal features
- Consider in children with unexplained persistent fever
- Laboratory evaluation recommended: CRP, ESR, complete blood count, albumin, liver enzymes, urinalysis 1
- Echocardiography should be performed if laboratory findings support the diagnosis 1
Treatment
First-Line Treatment
- Intravenous immunoglobulin (IVIG) at 2 g/kg as a single infusion (Level A evidence) 1
- High-dose aspirin (80-100 mg/kg/day divided into four doses) given with IVIG during the acute phase 1
For IVIG-Resistant Cases
- Second dose of IVIG
- Consider corticosteroids, TNF-α antagonists, or other adjunctive treatments 1
Long-Term Management
- Based on degree of coronary involvement
- Antiplatelet therapy
- Regular cardiac follow-up with echocardiography
- Risk stratification for physical activity 1
Important Clinical Pearls
- Kawasaki disease is the leading cause of acquired heart disease in children in developed countries 1
- Clinical features may not all be present simultaneously; careful history is essential 1
- The diagnosis should be considered in any child with prolonged unexplained fever
- Early treatment (within 10 days of onset) significantly reduces the risk of coronary artery aneurysms 2
- Cervical lymphadenopathy can sometimes be the most prominent initial feature, leading to misdiagnosis as bacterial lymphadenitis 1, 3
Remember that prompt diagnosis and treatment are critical to prevent coronary complications, which are the major cause of morbidity and mortality in Kawasaki disease.