Dr. Johnston is an Allergist/Immunologist in private practice and an assistant professor of Internal Medicine / Allergy /Immunology at the Edward Via College of Osteopathic Medicine. Dr. Johnston received his D.O. from New York College of Osteopathic Medicine in Old Westbury, New York. He completed his residency in Internal Medicine at Winthrop University Hospital in Mineola, New York, and received fellowship training in Allergy and Immunology at the University of Alabama at Birmingham. He serves on several professional committees which aim to improve the quality of care in the field of Allergy and Immunology. Dr. Johnston has been published in several journals and has an interest in Hereditary Angioedema and treatment strategies for Eosinophilic Esophagitis.