Commentary on Japanese Guideline for Food Allergy 2021 Chapter 5 Epidemiology and natural course

Abstract

The prevalence of food allergy in Japan is highest in infancy and decreases rapidly with age. The prevalence rate does not change significantly after adolescence. The main causative foods of immediate-type food allergy in Japan are hen's eggs, cow's milk, and wheat, but the types and ranking of these foods differ according to age groups. Recently, nut allergy in young children, especially walnut allergy, has increased rapidly. Cutaneous symptoms are highly prevalent in triggering immediate-type food allergy. Shock symptoms are also observed in approximately 10% of cases, indicating that food allergy is a very high-risk disease.

Children with food allergy in infancy develop bronchial asthma, allergic rhinitis, and atopic dermatitis at a high frequency. Thus, the risk of following the so-called "allergy march" is high.