have a fab holiday, from my experience you have a surge of allergy stress before you go, and then once you get on with holiday it gets easier.
translation cards for restaurants or hospital/ doctors
get extra health insurance for peace of mind.
get doctors letter for flight to explain auto injectors and other meds.
stick to similar rules for eating out you do at home, e.g
eat early, as they will have cleaner kitchen, and less people and more time to spend on you as you explain allergies.
pick easy to see meals, so plain food with no thick sauces.
labels in supermarkets in EU often have English on packet.
I had a list of the food in countries language so that any labels without English could be understood by me.
have fun, eat new foods you can eat, often people with allergies are allergic to common foods, so my son was able to try or at least consider eating frogs legs, snails, and new types of fish.
Food is not always the biggest part of a holiday, seeing new wonderful places and learning something new will provide your child with fantastic life experience and build confidence esp with regard to allergy. have a great time.