Geographic Variability of Childhood Food Allergy in the United States

Objective. The aim of this study was to describe the distribution of childhood food allergy in the United States. Methods. A randomized survey was administered electronically from June 2009 to February 2010 to adults in US households with at least 1 child younger than 18 years. Data were analyzed as weighted proportions to estimate prevalence and severity of food allergy by geographic location. Multiple logistic regression models were constructed to estimate the association between geographic location and food allergy. Results. Data were analyzed for 38 465 children. Increasing population density corresponded with increasing prevalence, from 6.2% in rural areas (95% confidence interval [CI] = 5.6-6.8) to 9.8% in urban centers (95% CI = 8.6-11.0). Odds of food allergy were graded, with odds in urban versus rural areas highest (odds ratio [OR] = 1.7, 95% CI = 1.5-2.0), followed by metropolitan versus rural areas (OR = 1.4, 95% CI = 1.2-1.5), and so on. Significance remained after adjusting for race/ethnicity, gender, age, household income, and latitude. Conclusions. An association between urban/rural status and food allergy prevalence was observed.