My dad has always had this theory, which I often do find to be true. Usually, the nicer the restaurant is, the higher the danger for my food allergies. Restaurants that are nicer and more expensive, tend to also be able to afford nicer, more expensive ingredients for their dishes. That is why, when I look at menus for expensive restaurants, I always see 'walnut butter', 'encrusted with almonds', etc. It is unbelievable how many dishes they can think of with allergens to include!
I also know that nuts are supposed to great flavor enhancers. That is why I have to avoid any baked goods. Many have some kind of nut, nut oil, almond extract, etc. There may also be hidden ingredients that I would never have suspected.
Avoiding really upscale, high class restaurants, is the best thing to do with food allergies.