Studies assessing food-induced allergic reactions and prehospital treatments in infants and young children are scarce. To describe differences in clinical characteristics in children aged 0 to 4 years presenting to the emergency department (ED) with food allergy (FA) reactions and investigate the association between prehospital epinephrine use and clinical outcomes. Retrospective cohort study of FA ED visits in Kaiser Permanente Northern California from January 2016 to December 2018. Charts were assessed on whether anaphylaxis criteria were met, and outcomes were reviewed after prehospital and ED treatments. A weighted cohort of 1518 children presenting with FA to the ED was evaluated. Infants presented with respiratory symptoms less often than did children age 1 and ages 2 to 4 years (6.8%, 16.1%, and 23.9%, respectively; P < .01), more frequently following first ingestion of offending food (74.8%, 44.2%, and 18.4%, respectively; P < .001), and with egg as the most common trigger (33.8%, 8.6%, and 5.3%, respectively; P < .001). Children younger than age 2 years had a tendency toward meeting anaphylaxis criteria less frequently than older children (31.3% vs 42.2%; P = .06), with ED epinephrine given in 12.6% overall. Prehospital epinephrine was given in 152 patients and was associated with a higher likelihood of admission for observation (adjusted odds ratio, 2.6; 95% CI, 1.0-6.5) but a lower likelihood of ED epinephrine treatment (adjusted odds ratio, 0.2; 95% CI, 0.1-0.5). Infants treated in the ED for FA reactions presented differently than older children. Most infants presented after first-known ingestion of offending foods. Overall, ED epinephrine use was low necessitating additional education to recognize and treat anaphylaxis in the ED.