Anaphylaxis: Definition and criteria.

Anaphylaxis is a systemic allergic reaction that may be severe and life-threatening. With more than a dozen anaphylaxis definitions proposed over the past several decades and several diagnostic criteria in circulation, there is a need for a multinational consensus definition to simplify management across specialties. Anaphylaxis diagnostic criteria are more alike than they are different, and approaches of the National Institute of Allergy and Infectious Disease, World Allergy Organization, and Brighton Collaborative help to add granularity and perspective to patient management. Anaphylaxis occurs across a spectrum of severity within populations, although, among individual patients, there is some evidence to suggest more consistency for an individual allergen. Still, severity is influenced by a number of factors that demonstrate variability: factors that relate to allergen triggers, patient characteristics, and treatments received. Severity of anaphylaxis impacts management, and recent guidelines provide approaches that consider individual factors to inform both strong and conditional recommendations. Conditional recommendations serve as navigational signals for shared decision-making when patient expertise is leveraged to inform individual preferences and values together with clinician expertise in anaphylaxis management to provide patient care bespoke to each patient. As novel approaches to both prevention and treatment of anaphylaxis emerge, an understanding of the significance of strong and conditional recommendations becomes critical to providing individualized and appropriate care for patients at risk for anaphylaxis.