Accurate Determination of Childhood Food Allergy Prevalence and Correction of Unnecessary Avoidance

Abstract

Purpose: Because the true prevalence of food allergy (FA), as based on the results of an oral food challenge test (OFC), is unknown, it is likely that children with suspected FA unnecessarily eliminate potentially causative foods. This study aimed to identify the prevalence of FA and to determine the proportion of children who unnecessarily eliminate food.

Methods: To identify children with FA, a primary survey was conducted via a questionnaire with all children aged 0-18 years in Niijima village (remote islands of Japan). In the secondary survey, a detailed medical interview was conducted by doctors with children who currently did not eat some foods. The third survey involved serum food-specific immunoglobulin E (IgE) tests and an OFC for children with suspected FA.

Results: Of 376 enrolled children, 374 (99.5%) completed the questionnaire. Some foods were eliminated by 18.6% and 13.0% of all children and those ≥6 years old, respectively. The target population for the secondary survey included 69 children who all completed the medical interview. The target population for the third survey consisted of 35 children, of whom 26 (74.3%) underwent the blood test. An OFC was performed 35 times with 20 children. As a result, the prevalence of FA was 4.9% in children of all ages and 4.7% in those ≥6 years old. Moreover, 55.0% children were able to cease eliminating food intake.

Conclusions: It is possible that a considerable number of children unnecessarily eliminate food because of suspected FA.

Keywords: Epidemiology; food allergy; oral food challenge test.

Fig. 1. Subgroup analysis. Groups A and B had experienced obvious FA symptoms (group A was within the previous year), and were currently completely eliminating the causative foods. Group C had not experienced FA symptoms previously but had never eaten potential causative foods. Group D still restricted their intake. Group E were able to eat without restriction. FA, food allergy.

Fig. 2. List of foods that were unnecessarily avoided. Eggs and milk were the particular food types that were unnecessarily avoided by all ages. For children ≥6 years old, yams, crustaceans, and fish eggs were the particular food types that were unnecessarily avoided.

Fig. 3. Study design and clinical outcomes regarding FA based on the 3 surveys conducted on children in Niijima village. As a result, the prevalence of FA for all ages was 4.9% (18 children). FA, food allergy; OFC, oral food challenge.