In previous studies, we demonstrated that IDECs and LCs expressing allergen-specific IgEs mediate an IgE-dependent delayed-type hypersensitivity reaction in response to environmental allergens (e.g., HDMs), and that this reaction can be observed in spongiotic dermatitis within lichenified eczema of adults and older adults with IgE-mediated AD [1,10,13]. This evidence concerns the gene IGHE and Alzheimer disease.