Questionnaire-based real-world survey of diagnosing food allergy in children: Utilization of oral food challenge tests and other diagnostic methods.

Background: Oral food challenge tests are considered the reference standard for diagnosing food allergies; however, studies on their real-world implementation rates are limited. Objective: The study aimed to investigate the proportion of school-age children who underwent the oral food challenge test and to understand the motivations behind food elimination and utilization of various health care services. Methods: The questionnaire-based survey for the parents of the students who submitted the "Certificate for School Life Management (For Allergic Diseases)" was conducted across public elementary and junior high schools in Gifu prefecture, Japan. Results: The study encompassed parents of 3457 children with food allergies who submitted the certificate. Approximately one third of those eliminating the 3 major allergens-eggs (32.5%), milk (27.6%), and wheat (33.5%)-were diagnosed via oral food challenge tests, and approximately two thirds were diagnosed using a combination of symptoms and blood tests, suggesting most children were diagnosed appropriately. However, many children were diagnosed and eliminated foods based solely on blood tests without any symptoms of other allergens, such as buckwheat (55.8%), peanuts (29.2%), and tree nuts (21.2%), suggesting that it was likely that these children unnecessarily eliminated foods. Elimination of buckwheat because of anxiety was associated with eliminating other foods for the same reason and with eliminating 2 or more foods. Conclusion: Examination of the real-world application of the proposed recommendations for the accurate diagnosis of food allergies suggests that closely monitoring their practical application should be conducted in each case to avoid unnecessary food elimination from children's diets.