Recent Dramatic Increase in Patients with Food Protein–induced Enterocolitis Syndrome (FPIES) Provoked by Hen’s Egg in Japan

Food protein–induced enterocolitis syndrome (FPIES) is a non–IgE-mediated gastrointestinal food allergy that occurs predominantly in infants and young children.1 Since the international consensus guideline for FPIES was released in 2017,1 epidemiological studies were conducted in many countries. However, there have been few longitudinal studies of FPIES, so we have lacked knowledge regarding possible changes in the trends of offending foods over the years. Recently, some case series of hen’s egg–induced FPIES (hen’s-egg FPIES) were reported from Japan;2-4 such cases had rarely been reported previously.