...which means you have to be particularly careful with your food-allergic child. And while you may have super-accommodating relatives who are more than willing to prepare allergen-free foods for your child, there are so many hidden sources of allergens to be aware of. The stuffing, for instance. Prepared without butter, sure- but what about the prepackaged bread cubes that went into the stuffing? And the turkey. Again, no milk or eggs were added, but some turkeys come pre-basted with butter. In any case, it's important that someone- whether it is you or the relative who prepares the food- check every ingredient along the way before allowing your child to try the dish.
I have been lucky enough to be able to generally oversee Thanksgiving dinner prep with my family (our dinners tend to be smaller, with maybe 8-10 people), so I know exactly what Bryan can and cannot have. However, I know that some Thanksgiving dinners are huge family potlucks with dozens of relatives and tables full of delicious, but most likely allergen-full, dishes. In this scenario, I would recommend contacting your host well in advance, explaining your situation, and offering to bring 1-2 things that you know your child will be able to eat. That way, no one else has to worry about keeping their food prep allergen-free, and you know that your child will have at least one thing he or she can have. You may also want to make special arrangements for your allergen-free dishes so that you can make sure there isn't any cross-contamination with other dishes.
Then there's the issue of dealing with relatives who don't have day-to-day contact with your food-allergic child, and therefore may not be aware of the issues that he or she faces. Well, that's kind of a personal preference. When Bryan was first diagnosed, we were very hypervigilant. Whenever we got together with anyone involving food, we would tell them about Bryan's allergies (even though he was eating his own food), and ask them to be very careful about washing hands and everything. Over time, I have become a little more relaxed (I know, it doesn't seem like it- but I really have!). I'm adopting more of a wait-and-see approach. I do watch over Bryan very carefully, and he does know to ask me before he eats something. And I still check labels and ingredients every time we give something to him. But I'm trying not to send out the blanket warning. If someone asks if Bryan can have something (just one bite of ice cream?), THEN I jump into teaching mode. But at this point, I'm trying to figure out how to balance informing people about his food allergies without stigmatizing him. I think it will get easier when I know I can trust Bryan to advocate for himself (and to not be tempted to try something yummy-looking!) But until then, it's a work-in-progress...
Hope that everyone has a fun, safe, and happy Thanksgiving!