Rob:

  I would tend to agree with Joy .... I would not do both things at once... if
there is a reaction it is more difficult to disern what the reaction is to.

  I also believe that allergic reactions change... they do not go away... I
have also seen cases that I refer to as the "bucket theory" ... the system can
handle "some" allergin but too much will cause a reaction... it is I think
more of a "tollerance" issue than an "allergy"...

 I also would like to know why there is a need to do a challenge at all...
many of us live quite well without cow's milk or cow's milk products...

                Patricia