Kawasaki Disease with Coronary Z-Score ≥2.5 or Age Under 6 Months: What to Do After IVIG Fails to Resolve Fever

Clinical scenario

This protocol addresses acute Kawasaki disease presenting with high-risk features: a coronary artery Z score of ≥2.5 for the left anterior descending (LAD) or right coronary artery (RCA) at initial echocardiography, or age under 6 months. A Z score of 2.5 is the threshold recognised as representing a true coronary aneurysm, rather than borderline dilation.

Previous treatment — goal not reached

A second course of IVIG was administered for persistent fever (with glucocorticoids as an alternative). Fever did not resolve. This protocol defines the evidence-based next step after that treatment failure.

Next-line approach (partial overview)

After repeated IVIG fails to resolve fever in this high-risk setting, the approach shifts to immunosuppressive therapy — with the specific agent category and the question of whether combination therapy is warranted determined by the severity of the clinical picture.

The treatment goal remains resolution of fever. The complete regimen, including agent selection criteria and escalation guidance, is available via the link below.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1002/art.42041

For this recommendation, the Voting Panel defined high-risk features as a Z score of ≥2.5 for the left anterior descending or right coronary artery at the time of the initial echocardiography and age <6 months.

This definition uses the Z score of 2.5 instead of 2.0, since a score of 2.5 is defined as representing a true aneurysm.

For patients with acute KD and persistent fevers after repeated treatment with IVIG, either nonglucocorticoid immunosuppressive therapy or glucocorticoids may be used.

Findings from studies of infliximab and cyclosporine for the treatment of refractory KD suggest some potential benefit of these agents.

Combination therapy (glucocorticoid with a nonglucocorticoid immunosuppressive agent) can be considered in severe cases, such as rapidly expanding aneurysms or imminently life-threatening disease.

View source ↗