Kawasaki Disease: Symptoms and Treatment
Kawasaki disease is diagnosed by the presence of fever lasting at least 5 days plus 4 of 5 principal clinical features: bilateral non-exudative conjunctival injection, oral mucosal changes, polymorphous rash, extremity changes, and cervical lymphadenopathy, with treatment consisting of intravenous immunoglobulin (IVIG) and aspirin to prevent coronary artery complications. 1, 2
Diagnostic Criteria and Clinical Features
Principal Clinical Features
- Fever: Typically high-spiking (>39°C to 40°C) and remittent, persisting for 1-3 weeks if untreated 1
- Bilateral bulbar conjunctival injection: Non-exudative, often sparing the limbus, without photophobia or eye pain 1, 2
- Changes in lips and oral mucosa: Erythema and cracking of lips, strawberry tongue, diffuse oral and pharyngeal redness 1
- Polymorphous exanthem/rash: Most commonly diffuse maculopapular eruption, scarlatiniform erythroderma, or erythema multiforme-like; typically involves trunk and extremities with accentuation in the groin 1
- Changes in extremities: Acute phase - erythema and edema of hands and feet; subacute phase - periungual desquamation beginning 2-3 weeks after fever onset 1, 2
- Cervical lymphadenopathy: Usually unilateral, ≥1.5 cm diameter, confined to the anterior cervical triangle; least common of the principal features 1
Diagnostic Algorithm
- Classic KD: Fever ≥5 days plus ≥4 principal clinical features 1
- In the presence of ≥4 principal features (particularly with hand/foot changes), diagnosis can be made with only 4 days of fever 1
- Experienced clinicians may diagnose with only 3 days of fever in classic presentations 1
- If coronary artery abnormalities are detected, diagnosis is confirmed even with fewer clinical features 2
Treatment Protocol
Initial Treatment
- IVIG: 2 g/kg as a single infusion, administered within 10 days of fever onset 3
- Aspirin: High-dose (80-100 mg/kg/day divided into four doses) until afebrile for 48 hours, then low-dose (3-5 mg/kg/day) as a single daily dose 3
- Treatment should be initiated promptly as delay beyond 10 days increases risk of coronary artery abnormalities 3
Management of IVIG-Resistant Disease (10-20% of cases)
- Second dose of IVIG (2 g/kg) for persistent or recrudescent fever at least 36 hours after initial IVIG 3
- Alternative options include infliximab or corticosteroids 3
Long-term Management
- Based on degree of coronary involvement 3:
Common Pitfalls and Special Considerations
Diagnostic Challenges
- Clinical features may not all be present simultaneously; careful history-taking is essential 1, 2
- Incomplete (atypical) KD should be considered in children with fever ≥5 days and only 2-3 principal features, especially in infants <6 months and children >5 years 4
- Exudative conjunctivitis, exudative pharyngitis, oral ulcerations, splenomegaly, and vesiculobullous or petechial rashes suggest alternative diagnoses 1
High-Risk Groups
- Infants <6 months often present with incomplete features yet have higher risk of coronary abnormalities 3
- Older children/adolescents frequently have delayed diagnosis and higher prevalence of coronary complications 4
Monitoring
- Echocardiography is recommended at diagnosis, 1-2 weeks, and 4-6 weeks after treatment for uncomplicated cases 3
- More frequent cardiac evaluation is needed for patients with coronary abnormalities 3
- Annual influenza vaccination is recommended for children on long-term aspirin therapy 3
- Measles and varicella immunizations should be deferred for 11 months after IVIG administration 3