Differences in allergic symptoms after the consumption of egg yolk and egg white

Hen’s eggs are one of the most common causes of food allergy. Although hen’s eggs are known to cause more gastrointestinal symptoms than other foods, it is not known whether there is a difference in organ-specific symptoms between egg yolk (EY) and egg white (EW). The present study aimed to determine whether there are organ-specific differences in the immediate symptoms of EY and EW in patients with hen’s egg allergies. We retrospectively investigated the immediate symptoms and treatment contents of those who had a positive result in an oral food challenge (OFC) of boiled whole EY or 10 g of boiled EW in our hospital from January 2013 to July 2019. We compared 80 patients in the EY-OFC-positive group with 106 patients in the EW-OFC-positive group. The EY-OFC-positive group had significantly fewer respiratory symptoms and significantly more gastrointestinal symptoms than the EW-OFC-positive group and had significantly more gastrointestinal symptoms only. In terms of treatment, significantly fewer patients in the EY-OFC-positive group required beta 2-agonist inhalation, and a significantly higher proportion of patients did not require treatment. Compared to EW, EY is more likely to cause gastrointestinal symptoms and less likely to cause respiratory symptoms. It may be necessary to discriminate between EY and EW allergy during diagnosis.