If you have food allergies, it is important to talk to the staff of a restaurant about them, to ensure that the food you are served is safe. Many restaurants use trace amounts of ingredients such as nuts, dairy, and shellfish in food which may not at first glance appear to have these substances. If the staff is aware of the issue, they can address it. The restaurant does not want you to have an allergic reaction to their food any more than you do, and most establishments are happy to work with customers who have special dietary needs.
If you make reservations to eat somewhere, always tell the staff about special needs you may have, such as those related to food allergies. The staff can alert the kitchen ahead of time about your food allergies, and the chef can consider alternate dishes for you. This is especially important if you are attending a fixed dinner, where the restaurant is providing a limited fixed menu. Making substitutions at the last minute can be difficult and costly, but if the kitchen knows about your food allergies ahead of time, they can make the evening run smoothly. Once you arrive at the restaurant on the evening of your reservation, remind the maitre d' about your situation, and make sure that your server knows as well.
If you are walking into a restaurant, you may find it useful to talk to staff about your food allergies before sitting down. A competent restaurant staff will check with the kitchen if they are unsure about anything on the menu, and should be able to give you several options for safe dining. If the staff thinks that they are unable to meet your needs, they can tell you this before you are seated.
When you talk to staff about your food allergies, remain polite. Many waiters and waitresses feel pressured because they have too many tables, or unexpected responsibilities. Let your waiter know that you would prefer that he or she check with the kitchen, rather than guessing about whether or not a dish is safe for you, and that you are happy to wait while the waitperson talks to the kitchen. Make sure to clearly define your allergy as well; some people, for example, are allergic to dairy in any form, while others are merely lactose intolerant, and can eat dairy products such as aged cheeses which have a minimal lactose content. This is especially important with peanut and nut allergies, which are sometimes poorly defined.
In a high quality restaurant, the wait staff and kitchen will accommodate your food allergies and try to ensure the best evening possible for you. In some establishments, food allergies are actually an excellent way to meet the chef, as he or she may come over to your table to see if the food is to your liking, especially if a dish has been customized for you. Never be ashamed to talk about your food allergies to staff in a dining establishment, because it is always better to be safe than sorry.