IGHE and peanut allergic reaction: This study enabled identification of specific IgE (sIgE) to the peanut component Ara h 2 as an important biomarker of peanut allergy2, 29 and provided a setting to show that increasing early‐life domestic exposure to peanut allergen in household dust increases the likelihood of subsequent peanut allergy in a dose–response fashion among children with FLG mutations, but not in those with FLG wild‐type genotype.30