Anaphylaxis is a potentially life-threatening allergic reaction. The overall prevalence of anaphylaxis appears to be rising in children, but temporal trends among infants and toddlers are not well studied.

To characterize the trends in US emergency department (ED) visits and hospitalizations among infants and toddlers with anaphylaxis from 2006 to 2015.

We conducted a study of temporal trends in anaphylaxis among children (age <18 years) and, more specifically, infants and toddlers (age <3 years) presenting to the ED between 2006 and 2015 using a large, nationally representative database. For internal consistency, we defined anaphylaxis using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes and excluded visits with International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes (late 2015). We calculated trends in the number and proportion of ED visits and hospitalizations and used multivariable logistic regression to identify predictors of hospitalization.

Among infants and toddlers, the proportion of ED visits for anaphylaxis per year increased from 20 per 100,000 visits to 50 per 100,000 visits (P_trend < .001). The rate of ED visits for anaphylaxis increased from 15 to 32 ED visits per 100,000 population of infants and toddlers (P_trend < .001). Food was the most commonly identified trigger. The proportion of hospitalization among anaphylaxis-related ED visits decreased from 19% to 6% (P_trend < .001). Among ED patients, those more likely to be hospitalized were male, privately insured, from higher income families, and presenting to urban, metropolitan teaching hospital EDs.

In a large, nationally representative US database, from 2006 to 2015, ED visits by infants and toddlers with anaphylaxis increased, whereas hospitalization of these patients decreased.