Incidence of Fatal Anaphylaxis: A Systematic Review of Observational Studies.

Background: Fatal anaphylaxis is very rare, with an incidence ranging from 0.5 to 1 deaths per million person-years.

Objective: Based on a systematic review, we aimed to explain differences in the reported incidence of fatal anaphylaxis based on the methodological and demographic factors addressed in the various studies.

Clinical Profile of Patients With Severe Anaphylaxis Hospitalized in the Spanish Hospital System: 1997-2011.

Background And Objective: Studies assessing the severity of anaphylaxis lack a comprehensive approach to collecting data on comorbidities that may worsen prognosis. Objective: Using the Elixhauser score (a systematic index associated with longer stay, hospital charges, and mortality), we determined which comorbidities were associated with more severe anaphylaxis.

Methods: We based our study on the Spanish Ministry of Health database of hospital discharges in Spain between 1997 and 2011.