Nobody's really allergic to the egg itself, unless they're eating it cold and eating it with other food. So, if you're eating an egg alone, you'll never have an allergy to it as long as it's room temperature.
Well, sometimes what happens is the body will use the liquid protein and the liquid fat to have a liver, gallbladder, pancreas, detoxification.
If that happens you might have diarrhea. You might have some cramping or vomiting that'll occur, but is not from the egg directly. It's what the body's utilizing the fat and proteins for, the detoxification.