What is the management of Kawasaki disease in outpatient (OPD) and emergency (casualty) settings?

Management of Kawasaki Disease in OPD and Casualty Settings

Immediate Recognition and Initial Treatment in Casualty

All children presenting with suspected Kawasaki disease should receive IVIG 2 g/kg as a single infusion combined with high-dose aspirin (80-100 mg/kg/day divided into four doses) as soon as the diagnosis is made, ideally within the first 10 days of fever onset. 1, 2

Key Diagnostic Points for Casualty Assessment

• Diagnose based on fever ≥5 days plus ≥4 clinical features: bilateral non-purulent conjunctival injection, oral mucosal changes, polymorphous rash, extremity swelling/redness, and cervical lymphadenopathy 1
• Incomplete Kawasaki disease (fever plus only 2-3 classic symptoms) requires immediate echocardiography and laboratory testing (CRP, ESR) - if coronary abnormalities or elevated inflammatory markers are present, treat immediately even without full criteria 1, 2
• Children under 1 year are at highest risk for incomplete presentation and paradoxically have higher rates of coronary aneurysms if untreated 1

IVIG Administration Protocol

• Infuse IVIG over 10-12 hours - faster infusion times (<10 hours) may be associated with higher coronary aneurysm rates 3
• Continue high-dose aspirin until patient is afebrile for at least 48 hours 1, 2
• After defervescence, reduce to low-dose aspirin (3-5 mg/kg/day as single daily dose) 1, 2

Management of IVIG-Resistant Disease (Casualty/Inpatient)

IVIG resistance is defined as persistent or recrudescent fever ≥36 hours after completion of initial IVIG infusion, occurring in 10-20% of patients. 1, 2

Treatment Algorithm for IVIG Resistance

First-line for resistance: Administer second dose of IVIG 2 g/kg as single infusion 1, 2, 4

Second-line options if fever persists after 2nd IVIG:

• Methylprednisolone 20-30 mg/kg IV for 3 days (with or without subsequent oral prednisone taper) 4
• Infliximab 5 mg/kg IV over 2 hours as alternative to steroids 4
• Both options show similar efficacy; infliximab may result in shorter hospitalization and fewer fever days 4

Third-line for highly refractory cases:

• Cyclosporine 4-6 mg/kg/day orally - taper by 10% every 3 days once afebrile and CRP ≤1.0 mg/dL 4
• Monitor for hyperkalemia (occurred in 32% of patients in trials) 4
• Reserve plasma exchange for patients failing all medical therapies due to significant risks 4

Outpatient Management and Follow-up

Antiplatelet/Anticoagulation Based on Coronary Status

No coronary abnormalities:

• Continue low-dose aspirin (3-5 mg/kg/day) until 6-8 weeks after disease onset 1, 2
• Discontinue if echocardiogram remains normal 1

Small coronary aneurysms:

• Low-dose aspirin indefinitely 1

Moderate aneurysms (4-6 mm):

• Low-dose aspirin plus second antiplatelet agent (clopidogrel 1 mg/kg/day, max 75 mg/day) 4, 1

Giant aneurysms (≥8 mm):

• Low-dose aspirin plus warfarin (target INR 2.0-2.5) 4, 1, 2
• Alternative: aspirin plus therapeutic low-molecular-weight heparin if warfarin difficult to regulate 4, 1
• This combination reduces MI risk significantly (1/19 with warfarin+aspirin vs 16/49 with aspirin alone) 4

Monitoring Schedule in OPD

• Frequent echocardiography and ECG during first 3 months - highest thrombosis risk occurs in first 15-45 days 1, 2
• More intensive monitoring for giant aneurysms 1, 2

Critical OPD Counseling Points

Vaccination modifications:

• Defer measles and varicella vaccines for 11 months after high-dose IVIG 1, 2
• Provide annual influenza vaccination for children on long-term aspirin therapy 1, 2

Medication interactions:

• Avoid ibuprofen in children on aspirin - antagonizes irreversible platelet inhibition 1

Physical activity:

• Encourage regular activity within parameters defined by ischemia/arrhythmia risk 4
• Provide written guidance on activity restrictions to prevent unnecessary inactivity 4

Common Pitfalls to Avoid

• Delaying treatment beyond 10 days significantly increases coronary artery abnormality risk 1
• Missing incomplete Kawasaki disease in infants under 1 year - maintain high index of suspicion 1
• Using 1 g/kg IVIG dosing instead of 2 g/kg - lower doses show significantly higher coronary abnormality rates (27% vs lower rates with 2 g/kg) 5, 6
• Infusing IVIG too rapidly (<10 hours) may increase aneurysm risk 3
• Failing to recognize IVIG resistance at 36 hours - early retreatment is critical 1, 2