October 15, 2020
Keio University School of Medicine
National Center for Child Health and Development
The Allergy Research Group of the Department of Pediatrics, Keio University (Professor Takao Takahashi, Lecturer Masaki Akashi, and Assistant Professor Kumiko Morita), in collaboration with Dr. Yoko Toyama, Head of Pediatrics at Kawasaki Municipal Kawasaki Hospital, and Dr. Hideaki Morita, Head of the Department of Immunology, Allergy, and Infectious Diseases at the National Center for Child Health and Development, analyzed the clinical characteristics of Food Protein-Induced Enterocolitis Syndrome (FPIES) caused by hen's eggs. The results revealed that, unlike common hen's egg allergies which are mainly caused by "egg white," FPIES is highly likely to be induced by "egg yolk."
Generally, hen's egg allergy is well known as an IgE-mediated allergy that causes dermatological symptoms (such as urticaria) and respiratory symptoms (such as sneezing, coughing, and wheezing) within one hour of consuming hen's eggs, especially "egg white." On the other hand, there is also Food Protein-Induced Enterocolitis Syndrome (FPIES), which primarily causes gastrointestinal symptoms (such as vomiting and diarrhea) several hours after consuming hen's eggs, and the number of patients with this condition is known to be increasing in recent years. However, its clinical characteristics had not been clarified until now.
Therefore, we analyzed the clinical characteristics of patients with suspected FPIES caused by hen's eggs who were seen at Keio University Hospital, Saitama Municipal Hospital, Keiyu Hospital, National Hospital Organization Tochigi Medical Center, Hiratsuka City Hospital, and Kawasaki Municipal Kawasaki Hospital between January 2015 and October 2019. The results showed that in patients with FPIES who experience gastrointestinal symptoms caused by hen's eggs, the symptoms are induced by "egg yolk" rather than "egg white."
In common IgE-mediated hen's egg allergy, it is generally considered that reactions are more common to "egg white" than to "egg yolk." Therefore, "egg yolk" has been thought of as a component that is relatively unlikely to induce allergic symptoms. However, caution is necessary in cases where repeated vomiting is observed several hours after consuming "egg yolk," as FPIES caused by hen's eggs is suspected.
By further advancing this research and identifying which components within "egg yolk" are the cause of the allergy, it is hoped that this will lead to the elucidation of the pathophysiology of FPIES and the establishment of treatment methods.
The results of this research were published in "Journal of Allergy and Clinical Immunology: In Practice" on October 13, 2020.
For the full press release, please see below.