Among the possible adverse reactions to gluten, celiac disease, non-celiac gluten sensitivity, and IgE-mediated wheat allergy have been classically described. A non-IgE-mediated reaction similar to food protein-induced enterocolitis syndrome (FPIES) after inadvertent gluten ingestion in a celiac patient was recently reported. We present three children affected by celiac disease with exquisite control, including appropriate adherence to an exclusion diet, who suffered a severe adverse food reaction after unappreciated outdoor ingestion of gluten, meeting the criteria for a definitive diagnosis of FPIES. The strict and prolonged exclusion of gluten from the diet is postulated as the possible trigger for this serious entity after an involuntary transgression. Although the first published cases are recent, we might be witnessing an increase in the frequency of presentation. Therefore, we believe emergency services must be alert to the possibility of diagnosis of FPIES in celiac patients due to involuntary transgressions. The determination of gluten glycoimmunopeptides in urine or stool samples may be useful for certifying the inadvertent consumption of wheat as the cause of FPIES.