What is the management of a child with Kawasaki disease who didn't improve with Intravenous Immunoglobulin (IVIG) and high-dose aspirin, and has left atrial dilation on echocardiogram?

Management of IVIG-Resistant Kawasaki Disease with Cardiac Involvement

For this child with IVIG-resistant Kawasaki disease and left atrial dilation, the next step is IV methylprednisolone (Option A), as this represents treatment failure requiring escalation beyond standard therapy.

Rationale for Steroid Therapy in IVIG-Resistant Disease

This patient has failed initial therapy with IVIG and high-dose aspirin, placing them in the approximately 10% of Kawasaki disease patients who are IVIG-resistant 1. The presence of left atrial dilation indicates significant cardiac involvement and ongoing inflammation requiring aggressive treatment.

The American Heart Association guidelines recommend that steroid treatment be restricted to children in whom 2 infusions of IVIG have been ineffective in alleviating fever and acute inflammation 1. However, given the cardiac involvement demonstrated by left atrial dilation, escalation to steroids is warranted even after a single IVIG failure.

Treatment Algorithm for IVIG-Resistant Disease:

First-line options after initial IVIG failure:

• Second dose of IVIG (2 g/kg) is the most commonly recommended first-line retreatment 1, 2
• IV methylprednisolone (20-30 mg/kg for 3 days) is an acceptable alternative to second IVIG 1
• Infliximab (5 mg/kg) can be considered as an alternative to second IVIG or steroids 1

In this specific case with cardiac involvement (left atrial dilation), IV methylprednisolone is the most appropriate choice because:

• The patient has already failed IVIG plus high-dose aspirin
• Cardiac involvement indicates high-risk disease requiring aggressive anti-inflammatory therapy
• Studies show steroids reduce fever duration and may improve coronary outcomes 1
• The most commonly used regimen is intravenous pulse methylprednisolone 30 mg/kg for 2-3 hours, administered once daily for 1-3 days 1

Why Other Options Are Incorrect:

Option B (Low-dose oral aspirin): This is inappropriate because:

• Low-dose aspirin (3-5 mg/kg/day) is used AFTER fever resolution, not during active refractory disease 2
• The patient is currently on high-dose aspirin and has not responded, so simply switching to low-dose would worsen outcomes
• High-dose aspirin should continue until fever resolves for at least 48 hours 2

Option C (Antibiotics): This is incorrect because:

• Kawasaki disease is not an infectious process requiring antibiotics
• The diagnosis is already established
• Antibiotics have no role in treating IVIG-resistant Kawasaki disease 1

Option D (Oral ibuprofen): This is contraindicated because:

• NSAIDs other than aspirin are not part of standard Kawasaki disease treatment
• Ibuprofen could interfere with aspirin's antiplatelet effects
• No evidence supports ibuprofen use in Kawasaki disease 1

Additional Management Considerations:

Aspirin dosing during treatment:

• Continue high-dose aspirin (80-100 mg/kg/day) until afebrile for 48 hours 2
• Then transition to low-dose aspirin (3-5 mg/kg/day) and continue for 6-8 weeks if no coronary abnormalities develop 2

Alternative steroid regimens if pulse therapy fails:

• Longer tapering course of prednisolone (2 mg/kg/day tapered over 2-3 weeks) may be considered 1
• Japanese studies show longer steroid courses may suppress persistent vascular inflammation more effectively 1

If steroids fail:

• Consider infliximab (5 mg/kg) as next-line therapy 1
• Cyclosporine (4-6 mg/kg/day orally) for highly refractory cases 1
• Plasma exchange reserved for patients failing all medical therapies 1

Critical monitoring:

• Frequent echocardiography to assess progression of cardiac involvement 2
• The left atrial dilation indicates this patient is at higher risk for coronary complications
• Monitor for development of coronary artery aneurysms, which peak in risk during the first 3 months 2