I have, on several occasions, experienced the joy of dealing with the consequences of Feorag eating something that, unbeknownst to either of us, contained egg products. It's not an allergic reaction as such and isn't life-threatening, but when the side effects of the plain old-fashioned dietary intolerance include vomiting and diarrhoea, I tend to curse the parties responsible ... especially as, after peanuts and wheat, egg occupies the #3 position in the dietary allergies pop charts.