Epidemiological Study of Hospital Admissions for Food-Induced Anaphylaxis Using the Japanese Diagnosis Procedure Combination Database

BACKGROUND: Food allergies are common among children, and food-induced anaphylaxis (FIA) is a serious disease with a risk of death; however, there is yet to be a large-scale epidemiological study on causative foods in Japan. The purpose of this study was to identify foods that cause FIA in Japan. METHODS: We identified 9,079 patients from the Japanese Diagnosis Procedure Combination Database who were admitted for treatment for FIA from April 1, 2014 through March 31, 2017. We extracted data on patient sex, age, use of epinephrine injections on the first day, prescription for epinephrine self-injection on the day of discharge, length of stay, readmission, and causative foods. RESULTS: The most common causative food was eggs, followed by wheat, milk, peanuts, and buckwheat. The most common causative food in each age group was eggs among 0–3-year-olds, milk among 4–6-year-olds, peanuts among 7–19-year-olds, and wheat among those aged 20 years and older. Epinephrine was used at admission among about 40%, 50%, and over 60% of cases in which the causative food was eggs; wheat, milk and peanuts; and buckwheat, respectively. The proportion of cases with a prescription for epinephrine self-injection at discharge was highest among those in which the causative food was wheat, followed by peanuts, buckwheat, milk, and eggs. CONCLUSIONS: FIA due to peanuts has become as common in Japan as it is in the West. These results suggest the importance of taking measures to prevent peanut allergies because children cannot make adequate decisions regarding food.