I think I am allergic to vanilla extract or eggs but I can't be sure. For as long as I can remember, I havn't been able to eat cookies, cake, cupcakes, brownies, custard icecream, and vanilla ice cream in general. For some reason, I am able to eat short bread cookies and soft serve ice cream without getting my allergic reaction. What happens, is my throat swells up almost immediately, only to the point where it's uncomfortable to swallow.