ABSTRACT
The incidence of severe systemic allergic reactions is increasing. Anaphylaxis and anaphylactoid reactions are provoked by a variety of factors, some of which are iatrogenic. Theoretically, most of these so-called allergic reactions are predictable and preventable; however, in real life, inadvertent exposure occurs. When severe reactions happen, epinephrine injected intramuscularly is the firstresponse medication of choice. H1-receptor antagonists are secondary and play a minor role in acute treatment. For the prevention of anaphylactoid and anaphylactic reactions, particularly iatrogenic reactions, however, H1-antagonists play an important role. A brief review of the provoking factors for anaphylaxis and anaphylactoid reactions is shown in Table 1.
