IGHE and Alzheimer disease: Similar to food allergy, atopic diseases, namely atopic dermatitis (AD), bronchial asthma, and allergic rhinitis, are another group of diseases in which the underlying pathophysiology involves excess production of either non-IgE or IgE mediated against harmless environmental proteins, such as pollen and dust mite [2,5]. Food allergies have always been linked to atopic diseases, and multiple important associations have been made between them.