Chapter 3: Food allergen

Abstract

The chapter on "Food Allergens" in the Japanese Guidelines for Food Allergy 2021 was written to organize the knowledge required for an overview of food allergens. First, general knowledge of allergens was mentioned, including the fact that the majority of food allergens are proteins, knowledge of allergen epitopes and mechanisms of allergen reduction. Next, the confusingly used terms cross-antigenicity and clinical cross-reactivity were explained, noting that cross-antigenicity does not necessarily mean clinical cross-reactivity and the extent to which clinical cross-reactivity occurs between foods that exhibit cross-antigenicity. Four protein superfamilies containing most plant food allergens, prolamin, cupin, Bet v 1 homolog [pathogenesis-related protein: PR-10], and profilin, and three protein superfamilies containing most animal food allergens, tropomyosin, parvalbumin, and casein, are described.