Diagnostic Challenges in Anaphylaxis.

Anaphylaxis is a severe and potentially life-threatening allergic reaction. Since its discovery over 100 years ago, research has led to great strides in describing pathophysiologic mechanisms of anaphylaxis; however, there is still imprecision regarding its definition and a lack of reliable, confirmatory testing. In this paper, we review definitions of anaphylaxis, highlighting studies examining the utility of the current clinical consensus definition. In addition, we evaluate current difficulties and limitations for both providers in acute care settings managing episodes and allergists evaluating patients after an episode has resolved. Finally, we provide an algorithm for outpatient evaluation of patients with a history of possible anaphylaxis.