What is the treatment for Kawasaki disease in children?

Treatment of Kawasaki Disease in Children

The standard treatment for Kawasaki disease in children consists of intravenous immunoglobulin (IVIG) 2 g/kg as a single infusion combined with aspirin, which should be administered as soon as possible within the first 10 days of illness to reduce the risk of coronary artery abnormalities. 1, 2

Initial Treatment Protocol

• IVIG should be administered at a dose of 2 g/kg as a single infusion, typically given over 10-12 hours, which has been shown to be the most effective regimen in reducing coronary artery abnormalities 1
• High-dose aspirin (80-100 mg/kg/day divided into 4 doses) should be given concurrently with IVIG during the acute phase for its anti-inflammatory effect 1, 2
• Treatment should be initiated as soon as possible after diagnosis, ideally within the first 7 days of illness, although treatment before day 5 may be associated with increased need for IVIG retreatment 1
• Even patients diagnosed after the 10th day of illness should receive IVIG if they have persistent fever without other explanation or have coronary artery abnormalities with ongoing systemic inflammation (elevated ESR or CRP) 1

Aspirin Dosing and Duration

• After the acute phase, when the patient has been afebrile for 48-72 hours, high-dose aspirin should be reduced to low-dose aspirin (3-5 mg/kg/day) for its antiplatelet effect 1, 2
• Low-dose aspirin should be continued until 6-8 weeks after illness onset if there are no coronary abnormalities 1
• For children who develop coronary abnormalities, aspirin may need to be continued indefinitely 1, 2
• Ibuprofen should be avoided in children taking aspirin for antiplatelet effects as it antagonizes the irreversible platelet inhibition induced by aspirin 1

Management of IVIG-Resistant Disease

• Approximately 10-20% of patients develop recrudescent or persistent fever at least 36 hours after initial IVIG infusion 2
• For IVIG-resistant cases, a second dose of IVIG (2 g/kg) should be considered as the first option 2, 1
• Alternative therapies for persistent IVIG resistance include corticosteroids, infliximab, or in rare cases, methotrexate 2, 3

Long-term Antiplatelet/Anticoagulation Management

• For patients with no coronary abnormalities, low-dose aspirin can be discontinued after 6-8 weeks 1
• Patients with small coronary aneurysms should continue low-dose aspirin indefinitely 2
• For moderate-sized aneurysms (4-6 mm), aspirin plus a second antiplatelet agent is recommended 2
• Patients with giant aneurysms (≥8 mm) require more intensive anticoagulation with low-dose aspirin plus warfarin (target INR 2.0-3.0) or low-molecular-weight heparin 2

Important Considerations and Potential Complications

• Children on long-term aspirin therapy should receive annual influenza vaccination due to the risk of Reye syndrome with concurrent influenza infection 1, 2
• Measles and varicella immunizations should be deferred for 11 months after high-dose IVIG administration 1, 2
• IVIG administration can occasionally be associated with adverse effects including aseptic meningitis and, rarely, thromboembolism due to increased blood viscosity 1, 4
• Coombs-positive hemolytic anemia has been reported as a complication of IVIG, especially in individuals with AB blood type 1
• Incomplete Kawasaki disease (fewer than 4 classic criteria) is more common in children under 1 year, who paradoxically have higher rates of coronary aneurysms if not treated 2

Monitoring

• Echocardiography should be performed at diagnosis, 1-2 weeks after treatment, and 4-6 weeks after treatment for uncomplicated cases 2
• More frequent echocardiography is recommended for patients with coronary abnormalities, particularly in the first 3 months when risk of thrombosis is highest 2
• The highest risk period for coronary artery thrombosis is within the first 15-45 days after diagnosis 2