Kawasaki disease in children younger than 6 months of age: characteristics of a Spanish cohort.

A retrospective study that compared children younger than 6 months versus older children of a Spanish cohort of patients diagnosed with Kawasaki disease between 2011 and 2016 (Kawa-Race study). From the 598 patients recruited, 42 patients were younger than 6 months (7%) and presented more frequently with an incomplete diagnosis of Kawasaki disease (52.4 vs 27.9%, p = 0.001). Cardiac abnormalities detected by echocardiography were more common in younger patients (52.4 vs 30%, p = 0.002). These younger patients presented with a higher proportion of coronary aneurysms as well (19 vs 8.6%, p < 0.001). Shock at diagnosis (9.5 vs 1.9%, p = 0.016) and admission to intensive care units (17.7 vs 4.1%, p = 0.003) were more frequent in patients younger than 6 months. There were no statistically significant differences in relation to infections, non-response to IVIG, or mid- or long-term outcomes.Conclusion: Data of the Spanish cohort are consistent with other American and Asian studies, although Spanish children younger than 6 months had a lower rate of non-response to IVIG and better clinical outcomes. A high index of suspicion should be considered for this population due to a higher risk of coronary abnormalities, presentation of shock, and admission to the intensive care unit. What is Known: •Children below 6 months of age with Kawasaki disease (KD) have different features compared to older. •Younger patients usually have an incomplete form of KD and coronary artery abnormalities. What is New: •Younger than 6 months with KD presented with shock and required admission to PICU more frequently compared to older. •Infections play a similar role in KD despite the age of the patients.