What is the recommended treatment for pediatric Kawasaki disease?

Treatment of Pediatric Kawasaki Disease

The recommended first-line treatment for pediatric Kawasaki disease is intravenous immunoglobulin (IVIG) at a dose of 2 g/kg as a single infusion, combined with aspirin therapy. 1, 2

Initial Treatment Protocol

• IVIG should be administered at 2 g/kg as a single infusion within the first 10 days of illness, preferably within 7 days, to reduce the risk of coronary artery abnormalities 1
• High-dose aspirin (80-100 mg/kg/day divided into 4 doses) should be given concurrently with IVIG until the patient is afebrile for at least 48 hours 1, 2
• After fever resolution for 48-72 hours, transition to low-dose aspirin (3-5 mg/kg/day) as a single daily dose for its antiplatelet effects 1, 2
• Low-dose aspirin should be continued until 6-8 weeks after disease onset if no coronary abnormalities develop 1
• For children who develop coronary abnormalities, aspirin may be continued indefinitely 1

Management of IVIG-Resistant Disease

• Approximately 10% of patients fail to respond to initial IVIG therapy (defined as persistent or recrudescent fever 36 hours after completion of initial IVIG) 1, 2
• For IVIG-resistant cases, a second dose of IVIG (2 g/kg) is recommended as the first-line treatment 1, 2
• If fever persists after two doses of IVIG, corticosteroid therapy should be considered 1, 2
• The most commonly used steroid regimen is intravenous pulse methylprednisolone (30 mg/kg) administered once daily for 1-3 days 1

Long-term Antiplatelet/Anticoagulation Management Based on Coronary Status

• For patients with no coronary abnormalities: discontinue aspirin after 6-8 weeks 1
• For patients with small coronary aneurysms: continue low-dose aspirin (3-5 mg/kg/day) indefinitely 1, 2
• For patients with moderate-sized aneurysms (4-6 mm): consider aspirin plus a second antiplatelet agent that antagonizes adenosine diphosphate-mediated activation, such as clopidogrel 1, 2
• For patients with giant aneurysms (≥8 mm): use low-dose aspirin plus warfarin (target INR 2.0-3.0) or aspirin plus therapeutic doses of low-molecular-weight heparin in infants or children where warfarin is difficult to regulate 1, 2

Important Clinical Considerations

• Ibuprofen should be avoided in children with coronary aneurysms taking aspirin for its antiplatelet effects, as it antagonizes the irreversible platelet inhibition induced by aspirin 1
• Children on long-term aspirin therapy should receive annual influenza vaccination to reduce the risk of Reye syndrome 1
• Measles and varicella immunizations should be deferred for 11 months after high-dose IVIG administration 1, 2
• Even with optimal treatment within the first 10 days of illness, approximately 5% of children develop transient coronary artery dilation and 1% develop giant aneurysms 1

Recent Evidence on Aspirin Use

• A 2025 randomized clinical trial found that IVIG alone was non-inferior to IVIG plus high-dose aspirin for reducing coronary artery lesions in Kawasaki disease, suggesting that high-dose aspirin may not provide additional benefit for coronary outcomes 3
• However, this single study does not yet override the established guidelines recommending combination therapy with IVIG and aspirin 1, 2

Common Pitfalls and Caveats

• Delaying treatment beyond 10 days significantly increases the risk of coronary artery abnormalities 2
• Incomplete Kawasaki disease (fewer than 4 classic criteria) is more common in children under 1 year of age, who paradoxically have higher rates of coronary aneurysms if not treated 2
• The highest risk for coronary artery thrombosis occurs within the first 3 months after diagnosis, with peak incidence in the first 15-45 days 2
• IVIG should be administered over 10-12 hours to minimize the risk of adverse effects and potentially improve outcomes 4