IGHE and allergic disease: The detailed analysis of the evolution of allergic sensitization from early childhood to adolescence suggests that allergic sensitizations occur early in life and, depending on genetic and environmental factors, in particular in response to repeated allergen contact, progress from clinically silent forms of IgE sensitizations which are characterized by the presence of low levels of allergen-specific IgE antibodies in the blood without accompanying symptoms towards symptomatic allergy (3, 4).