This is why my father avoids Breakfast flights. In addition to a gluten allergy he is also allergic to eggs and, in particular, the powdered eggs that Delta uses sets off his allergy just by putting it near him (to the point of his throat starting to close). If he is stuck he will just order the cereal option and not eat the cereal since the rest of the food he can eat and sometimes he will get lucky that the catered cereal is gluten free (when they serve Chex as the cereal option)