In a message dated 1/29/2007 5:19:38 AM Eastern Standard Time, 
Alex Oren  writes: 
> In that case, just one additional question.
> 
> If she has a GI reaction, how would we know if it is allergic in nature =
> or due to lactose intolerance?

You would have to find a food that contained protein but no lactose or 
lactose but no protein and test that.

A doctor can easily test for lactose, because pure lactose is available as 
part of a lactose intolerance test kit. Allergy test kits would have just the 
protein.

With GI symptoms, which are less threatening than anaphylactic reactions, you 
could also do a test challenge at home. Lactose-free milk is the obvious 
candidate. Alternatively, aged cheese contains virtually no lactose, but is high 
in protein.

Foods containing lactose but no protein are harder to specify. However, 
lactose is used in numerous commercial food products as a sweetener, and is often 
in foods that contain no other dairy product. You could check ingredients lists 
for something that your daughter would eat.

BTW, the comment about yogurt not reacting differently was in response to its 
being used in an allergy test. Yogurt is usually better tolerated by people 
with lactose intolerance than other milk products because the bacterial 
cultures in it help digest the lactose.

Steve Carper
Steve Carper's Lactose Intolerance Clearinghouse
http://ourworld.compuserve.com/homepages/stevecarper/

Planet Lactose Blog
planetlactose.blogspot.com