I don't know specifically about subs, but if you check sparkrecipes.com
you should be able to find lots of recipes without the items you're allergic to. Do you eat vegetarian? I know sometimes if there's a certain item I might not have (not allergic to anything & like EVERYTHING), I just omit it. On one of sparkpeople's chili recipe, for instance, I see it has peppers, but I make mine with onions, celery & carrots. I'd be likely to use whatever veggies I have on hand, rather than be concerned about using everything it calls for......but that's just me.
When looking up recipes, if you DO eat vegetarian, just type 'vegetarian' & recipes will come up that don't contain nuts.
I also Google a lot.....when I typed 'sub for nuts,' this was one answer: I use Grape Nuts cereal to add to cookies in place of nuts when baking.'
With any luck, you might get a response from one of the nutritionists.