19The combination of severe atopic manifestations (especially when multiple), including urticaria, angioedema and anaphylaxis, with one or more of the following laboratory findings increases the possibility of a PAD:Very high levels of total IgE (any age) >10,000 kU/L.Increased absolute number of eosinophils in blood (any age) >10,000 cells/mm3.Basal high levels of tryptase and/or histamine in blood. Here, IGHE is linked to urticaria.