Weird question, I know, but just a couple of examples -
I have a shellfish allergy and react worst to shrimp scampi, but I can eat grilled or deep-fried shrimp with no problem.
Same with eggplant - we make a dish called baingan ka bhartha, which is the eggplant all cooked with its skin and everything. Causes an allergic reaction. Fried or grilled eggplant? Not a problem.
I have always guessed it has something to do with the fact that all the juices are cooked right in in scampi and such, but I don’t know. I did look up allergies before I came here, but it seems to be pretty presumed that people either have them or don’t.
My questions are, Does it make a difference, and do other people react the same as me?
It can make a difference, but this answer is based on a basic knowledge of biochemistry and not of the specific biochemistry of the situation.
Many of the substances which are biochemically important need to have not just a specific composition but also a specific spatial organization, in order to “work”. Proteins need to be in a specific 3D shape, and different shapes will not work or may even make you sick (mad cow’s disease is caused by misfolded proteins, called “prions”); carbohydrates are digestible via enzymatic processes or not depending on how the individual sugars are connected to each other (they are always digestible via chemical processes, but those take longer; carbohydrates which are not digestible by human enzymes form the largest part of what we call “dietary fiber”).
Cooking something breaks some large molecules into smaller pieces; for others, the molecule isn’t broken but it is unfolded (this is the main process when frying eggs). The conditions under which something is cooked produce not just a different chemical composition in terms of, for example, “if you fry something it will have oil, if you boil it in plain water it will not”: it can also change in terms of “when you fry carbs, part of the fats bond with the carbs; how much of this bonding happens will depend on factors like the composition of the oil/fat used and the temperature”.
So, making that whole mess short: yes, cooking something in different ways means that the chemicals you’re eating are different, so it is possible that one method of cooking produces your allergens and another one doesn’t (in a case similar to yours, my brother can eat cooked chorizo, pepper and peppers, while the same products raw make him break into The Rash From Hell). Still better be careful around known allergens, of course, but you know that already.