Eosinophilic Granulomatosis with Polyangiitis (EGPA), previously known as Churg-Strauss syndrome, is a lifethreatening disease seen in both children and adults in which the body’s immune system targets its own blood vessels resulting in asthma, arthritis, breathing difficulties, and more. Despite clear evidence that children and adults experience disease differently (both physically and mentally), diagnostic criteria and therapies have only been studied in adults. The goal of this project is to use the resources within CARRA to collect the current available data on children with EGPA and assess for gaps in knowledge. I will then develop methods to optimize data collection and design a pediatric study to validate the Diagnostic and Classification Criteria in Vasculitis Study’s recently developed ACR-EULAR criteria for EGPA. This knowledge is critical to accelerate research in EGPA in children, with an overarching goal to improve care and reduce disability from this disease.