IGHE and Alzheimer disease: Skin is an important portal for sensitization to food.20 Food allergy is common in patients with atopic dermatitis (AD), a disease characterized by a disrupted skin barrier21,22 and associated with increased intestinal MC load and intestinal permeability.23,24 In mice, epicutaneous sensitization by application of antigen to skin that has been tape stripped to disrupt its barrier function results in IgE sensitization and allergic skin inflammation with features of AD, increased intestinal MC load and intestinal permeability, and IgE-mediated anaphylaxis following oral antigen challenge.24–26