Considered “transitional” a generation ago, milk and egg allergies now appear to be more persistent and harder to outgrow, according to new research. In what are believed to be the largest studies to date of children with milk and egg allergies, researchers followed more than 800 patients with milk allergy and nearly 900 with egg allergy over 13 years, finding that, contrary to popular belief, most of these allergies persist well into the school years and beyond.