The Challenge of Establishing the Burden of Anaphylaxis: Some Recent Trends

Abstract

This review aims to describe some of the limitations in defining anaphylaxis and therefore the difficulties in studying its epidemiology. Despite these limitations we also aim to describe some of the trends observed in recent studies. The epidemiological study of anaphylaxis is problematic. Although first described over 100 years ago, the definition of anaphylaxis has undergone revision in the last 2 decades, and a new international consensus definition was proposed in 2014. Clinical diagnostic criteria have been in use for little over a decade. Mast cell tryptase can be used to confirm the diagnosis, but is not always available, is of little use in determining immediate treatment and is not performed in many cases of suspected anaphylaxis. Epidemiological studies rely on clinical diagnosis and medical coding systems which have many limitations. Recent changes adopted in the ICD-11 will aid the detection and classification of anaphylaxis cases. The absence of an objective gold standard and the difficulty in data quality at a population level mean that reliable epidemiologic data are difficult to obtain. Anaphylaxis seems to be increasing, with food-induced case in paediatrics and drug-induced cases in adults the main drivers.