Editorial comment on “Frequency of fatal and recurrent anaphylaxis due to cow's milk: A systematic review and meta‐analysis of observational studies”

Abstract

Pérez-Codesido et al have performed a systematic review and meta-analysis aiming to assess the frequency of recurrent and fatal anaphylaxis due to cow milk allergy in children. 1 Anaphylaxis is a potentially life-threatening event, and cow milk is one of the most frequent causes of food anaphylaxis in children. 2,3 However, as Pérez-Codesido et al have shown, the epidemiology and impact of cow milk anaphylaxis remain insufficiently studied. In fact, their systematic review has identified a small number of primary studies assessing the frequency of either recurrent or fatal anaphylaxis due to cow milk allergy. Not only these studies are few in number but also their estimates are quite disparate. For instance, recurrent anaphylaxis was reported across the different studies as ranging from 16% to 76%. Regarding fatal anaphylaxis, a Bayesian pooling of the provided estimates would result in 0.018 deaths per 1,000,000 persons-year, with a credibility interval ranging from 0.006 to 0.042 deaths per million year. If this estimates could be applied to the general United States or European Union pediatric populations, this would imply a number of yearly deaths ranging from 1 to 16 and from 1 to 21, respectively (Figure 1). These disparate numbers reflect the important across-study heterogeneity (indeed, the authors opted for not presenting pooled values for fatal anaphylaxis on account of severe meta-analytical