Hi,
 
This is not a very technical answer, but as I understand it, milk
allergy is a body-wide response to milk in the system, whereas
lactose intolerance affects mainly the digestive system, because it
can't handle milk sugar.  The allergy can be life-threatening but
the intolerance is usually just unpleasant.  Also, intolerance often
develops slowly during the late teens and the twenties, but allergy is
often present at birth or develops rapidly (is that correct about the
allergy?)
 
As a lactose-intolerant only I can eat products containing casein with
no ill effects, but apparently this is not so with allergics.
 
This isn't reccommended for everyone, but to test what was really
going on, years ago, I bought a bottle of lactose powder from a
health-food store and ate a considerable quantity.  In about two
days--sick, sick, sick!  I got over it though.  :)  If any other lactose
intolerants want to trade favorite strategies and products they are
welcome to write to me privately.
 
--Anne   [log in to unmask]