Perspectives on anaphylaxis epidemiology in the United States with new data and analyses

Abstract

Anaphylaxis incidence rates and time trends in the United States have been reported using different data sources and selection methods. Larger studies using diagnostic coding have inherent limitations in sensitivity and specificity. In contrast, smaller studies using chart reviews, including reports from single institutions, have better case characterization but suffer from reduced external validity due to their restricted nature. Increasing anaphylaxis hospitalization rates since the 1990s have been reported abroad. However, we report no significant overall increase in the United States. There have been several reports of increasing anaphylaxis rates in northern populations in the United States, especially in younger people, lending support to the suggestion that higher anaphylaxis rates occur at higher latitudes. We analyzed anaphylaxis hospitalization rates in comparably sized northern (New York) and southern (Florida) states and found significant time trend differences based on age. This suggests that the relationship of latitude to anaphylaxis incidence is complex.

Fig. 1

Anaphylaxis hospitalization rates for residents of New York and Florida between 1996 and 2005. Rates among New York children and adolescents (NY-C) and New York adults (NY-A) are reported along with rates among Florida children and adolescents (FL-C) and Florida adults (FL-A). Children and adolescents were 0 to 19 years of age, and adults were 20 years of age and older. Time trends were evaluated by entering the discharge year as a continuous variable in negative binomial regression models. ^aThe P values are for change in rate for each 1-year increase in discharge year from a negative binomial regression model