My wife has had nut allergies in the past. Recently she has successfully challenged some of them, but still avoids them as an ingredient in dishes she orders. She still describes herself as having a nut allergy when at restaurants, so that the kitchens will be careful about cross contamination when preparing her food. We rarely find a restaurant where we live that will tell us that they can't accomodate this. For our trip to London this July, I've been looking at restaurant possibilities for lunch and dinner that are close to the sites we'll be visiting. On a number of the menus I've looked at online, I see a disclaimer saying that because they include nuts in some of their dishes they can't "guarantee" that there won't be nuts or nut traces in all of their dishes. The word "guarantee" is always in these disclaimers. Because my wife's remaining allergies aren't extreme, we don't need a guarantee, we'd be okay if the restaurant told us they would take care. Anyone out there have experience with someone in your travelling party who has a nut allergy, who can comment on whether we should steer clear of these places with disclaimers? Might sound like a dumb question, but I've seen enough of the disclaimers that I wonder if the local health regulations require them to have it, but it doesn't necessarily mean they couldn't accomodate us.
I traveled in 2008 to England and France with my adult son who has a severe nut allergy. We found that at most restaurants in London, as soon as he mentioned the nut allergy they refused to prepare him any food. Several times he sat and drank his beer while we ate and then visited McDonald's afterward. Outside of London, our experience was exactly opposite and in one pub in a small village, the chef came out of the kitchen to speak with my son and explain how he was preparing each dish that he ordered to ensure that no nuts would be in it or near it. It all depends on how comfortable you are with the assurances that are given - my son's allergies are severe enough that he carries an Epipen everywhere with him and so he would only eat the food when he was confident that it was safe for him to do so. All restaurants seem to have the disclaimer so I would handle it on a case by case basis and make sure you are comfortable with how the staff handle your request.
The disclaimer is so they don't get sued if somebody with an extreme nut allergy dies because a single stray molecule of nut protein got into their dish. If your wife's allergies aren't life-threatening, I would explain when you go into the restaurant and go by whether they seem trustworthy.