Hi --

If you do a google search on "allergy and travel" you'll find a number of
web sites with useful information for you. Some thing they recommend include
having at least two allergy cards, laminating them, and where to buy
ready-made ones. If you google for "milk allergy travel" you'll additionally
find advice that's specific to this allergy. For example, when in France
look for restaurant that specialize in dishes from the south of France which
typically use olive oil instead of butter, or go out for Vietnamese.

I hope this additional information is helpful,
--Beth Kevles
  Eating without Casein webmaster
  http://web.mit.edu/kevles/www/nomilk.html