To conclude, atopic dermatitis is a predominantly type-2-mediated disease, and although the presence of IgE is common in AD patients, and high IgE levels is one of the major diagnostic criteria of AD, it cannot be characterized as a type I hypersensitivity reaction, and hence, the precise role of IgE in the disease is not yet fully elucidated. This evidence concerns the gene IGHE and Alzheimer disease.