1Division of Allergy & Immunology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA;

2Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA;

3Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.

Correspondence: Evan S. Dellon, MD, MPH. E-mail: [email protected].