In Reply We thank Dahlberg and Everhov for their implicit validation of the representativeness of our study cohort and for advertising the fact that IgE-mediated allergy was associated with a reduced odds of complicated appendicitis.1 In our center, children with IgE-mediated allergy had 3 times lower risk of complicated appendicitis (adjusted odds ratio, 0.33; 95% CI, 0.18-0.59), after adjustment for age, sex, primary health contacts, seasonal antigenic exposure, allergy medications, and duration of symptoms. We appraised unmeasured confounding but not the risk of selection bias, and we therefore welcome the endorsement offered by Dahlberg and Everhov. The rate of our primary exposure was on par with the mean allergy prevalence in their unique BAMSE project,2 an ongoing, longitudinal, prospective birth cohort including more than 4000 Swedish children.