Anaphylaxis: pathophysiology, clinical presentations and treatment.

Anaphylaxis and anaphylactoid reactions are abrupt, often life-threatening episodes, secondary to the liberation of certain chemical mediators, and their effects on target organs. The number of agents known to trigger such reactions is expanding, with the most common fatal reactions secondary to penicillins, iodinated contrast material (ICM), and hymenoptera stings. Limited studies point to upper airway obstruction and circulatory collapse as the causes of death in man. It is felt that the frequency of cardiovascular involvement is not widely appreciated, and that hypotensive patients can be markedly hypovolemic. The primary goals of treatment should be aimed at preventing or reversing complications, and include immediate attention to the airway, cardiac monitoring, and establishment of intravenous access. The cornerstone of pharmacologic therapy is epinephrine. A comprehensive review of the pathophysiology, symptomatology, and treatment is presented.