A 12-week-old male with a 10-day history of fever.

Kawasaki disease (KD) is a self-limited vasculitis that can have significant morbidity and even mortality if not identified and treated early. The purpose of this case study is to highlight the importance of keeping KD in the differential diagnosis, even if all clinical criteria are not met. This is especially true in children younger than 1 year of age, who are more likely to have an incomplete or atypical presentation. The patient in this study is a 12-week-old African-American male with no significant past medical history who presented with a 10-day history of fever up to 105° F. An echocardiogram shortly after admission demonstrated normal cardiac structure and function with evidence of coronary artery abnormalities. Diagnosis of KD (treatment with intravenous immunoglobulin, aspirin, and a tumor necrosis factor-alpha inhibitor) and follow-up imaging are detailed. Treatment of KD in the acute phase is aimed at preventing coronary thrombosis and aneurysm formation.