For infants with severe AD and/or FA, we recommend medical counselling before introducing common food allergens into the diet (i.e., egg, dairy, wheat, fish, and peanut), to exclude an IgE-sensitization to those foods, which would increase the risk of reaction upon ingestion, and to discuss the best timing and modalities of such introductions in light of the available evidence for FA prevention. The gene discussed is IGHE; the disease is Alzheimer disease.