id progression of life-threatening symptoms. The cause of anaphylactic reactions is the activation of mast cells through antigen binding and cross-linking of IgE; the symptoms result from the tissue response to the release of mediators such as histamine, proteases, prostaglandins, and leukotrienes and typically include flushing, hives, laryngeal edema, wheezing, nausea, vomiting, tachycard