Refractory Kawasaki Disease with Giant Coronary Artery Aneurysms in An Infant: A Clinical Conundrum

Dear Editor, Kawasaki disease (KD), although being the most common cause of multisystem vasculitis in childhood, is rare in infants under 6 months of age, often presenting with non-classical symptoms, thereby delaying treatment initiation, and resulting in higher rates of coronary artery (CA) abnormalities.[1] A 3-month-old male infant presented to the pediatric emergency department with a 10-day history of high-grade fever, irritability, rhinorrhea, watery diarrhea, and mucosal congestion of the oral cavity.Examination revealed bilateral non-exudative conjunctivitis, erythematous cracked lips, and erythema and edema of the palms and soles.Laboratory evaluation showed anemia, leukocytosis, thrombocytosis, elevated inflammatory markers, hypoalbuminemia, and sterile pyuria.Based on American Heart Association criteria, a diagnosis of complete KD was established.Baseline 2D-echocardiography on day 10 of fever (day 1 of admission) demonstrated CA dilatation with the left anterior descending (LAD) artery measuring 5.11 mm (z score: 13.7, n < 2.5), the left circumflex (LCx) artery measuring 4.47 mm (z score: 10.4, n < 2.5), and the right coronary artery (RCA) measuring 4.08 mm (z score: 8.39, n < 2.5), placing him at high risk for giant coronary artery aneurysm (CAA) formation [Figure 1a and b].He received intravenous immunoglobulin (IVIG, 2 g/kg) and methylprednisolone (2 mg/kg/day) in addition to high-dose aspirin (80 mg/kg/day).Fever subsided temporarily, but recurred on day 17 of illness (day 7 of admission).Repeat echocardiography revealed worsening CA dilatation (LAD -6.58 mm, 18.3 z; LCx -5.83 mm, 14.8 z; RCA -6.73mm, 15.9 z) [Figure 1c and d, Supplementary Video 1].A second IVIG infusion was administered, and methylprednisolone was continued.Anticoagulation with warfarin was initiated.Computerized tomography (CT) angiography at three weeks of illness (day 12 of admission) showed giant aneurysms in the LAD (6.92 mm, Z score 19.3), LCx (6.19 mm, Z score 15.5), and RCA (5.08 mm, Z score 14.1), respectively [Figure 2a-c, Supplementary Video 2].Despite marked dilatation, there was no evidence of intraluminal thrombus.e child recovered well after the second dose of IVIG with resolution of fever and inflammatory parameters and was discharged on aspirin (3 mg/kg/day), warfarin (INR-guided, between 2 and 3), and a tapering dose of steroids, with advice for strict cardiology follow-up.e serial echocardiographic and CT images in our infant strikingly demonstrate rapid evolution from coronary dilatation to giant aneurysms within a few days, despite administration of two https://jcardcritcare.org