In addition, allergen crosslinking of IgE/FcεRI activates de novo synthesis of leukotrienes, prostaglandins, and platelet-activating factor that contribute to the characteristic symptoms of an allergic reaction and anaphylaxis.37, 38, 39, 40 In addition, IgE may be involved in sustaining the type 2 immune response in several different ways. Here, IGHE is linked to anaphylaxis.