Symptoms of egg yolk‐associated food protein‐induced enterocolitis syndrome appear following prolonged cessation

Food protein-induced enterocolitis syndrome (FPIES) is a nonimmunoglobulin E (IgE)-mediated food allergy. Most patients with solid FPIES experience a period of asymptomatic intake of the causative foods before onset. This study aimed to elucidate the pattern of egg yolk (EY) ingestion that triggers FPIES. We retrospectively compared consumption intervals during the asymptomatic period to those just before the first FPIES episode in 24 patients with oral food challenge test-confirmed EY-FPIES, for whom complete data regarding the dates of EY consumption before onset were available. The average interval during the asymptomatic period and that between the last asymptomatic consumption and onset were 2.2 ± 2.3 (median, 1; interquartile range [IQR], 1-3; 95% confidence interval [CI], 1.75-2.68) days and 17.1 ± 12.7 (median, 13; IQR, 8-29 days; 95% CI, 11.70-22.46), respectively. The onset of FPIES is associated with prolonged cessation after asymptomatic consumption.