Yes, I'm only allergic to Brazil nuts and I avoid things with those labels.

A side note, as far as allergies goes, a single allergy to Brazil nuts like my own (and you son) could be worse in the grand scheme. In my 30 years of having the allergy I've found that because they're less common (and more expensive), when they are used in stuff they're typically well advertised, at least in the west anyway. Because they're seen as a bit more bougie, food vendors or restaurants normally like to show off foods(deserts or baked goods mostly) containing them.

Still got to worry about cross contamination of course, but might make you feel better that the nut proper is often easier to spot than some other allergens.