On our pediatric intensive care unit, we successfully treated a 10-year-old boy with severe pulmonary edema due to anaphylaxis after his last injection of a 3-year course of allergen immunotherapy (AIT). In view of the severity of the adverse event, we initiated a case analysis with all involved medical professionals. The evaluation revealed delayed administration of epinephrine due to dosing uncertainty and underestimation of severity. Consequently, all involved institutions established epinephrine auto-injectors (EAIs) in their emergency equipment. We suggest providing EAIs in every practice conducting AIT, as well as in pediatric emergency rooms and ambulances. We would like to remind readers of the risk of anaphylaxis, even on the last day of AIT.