Moreover AD, especially the early-onset kind, could represent the first step of the atopic march[10,11] and it is a major risk factor for the development of asthma; and patients with specific IgE antibodies to common environmental allergens present a higher risk for progressing in the atopic march to respiratory allergic diseases, such as rhinitis and asthma, than those without IgE sensitization. This evidence concerns the gene IGHE and Alzheimer disease.