From my darling sister and her unfortunate allergy to seafood–l’horreur!— to some dear ones whose otherwise healthy constitutions cannot bear the humble peanut, food sensitivity makes for tricky travel. Thrill seeking could be part of one’s itinerary, but treating anaphylactic shock, not so much.
Need to communicate your allergies in Khmer, Catalan or Croatian? Fear not, thanks to the ingenuity of Select Wisely, declarations of several food allergies have been translated into over 40 languages and printed on easy-carry laminated cards (some with photos provided for good measure.) Translation cards for other health concerns, such as Diabetes and Asthma are also available and the website offers useful travelers tips.
As essential as your Passport, stow them in your carry-on.