IGHE and anaphylaxis: With the recent emergence of several gene knockout mice (FcЄRI, histamine decarboxylase, IL-4Rα) there has been significant focus on employment of animal models of IgE-mediated passive and active systemic and oral antigen-induced anaphylaxis in an attempt to decipher the relative contributions of inflammatory cells and cytokines to disease pathogenesis [6,8].