Hello Mariah,
Lots of things come to mind and others on the list will have suggestions
too, I'm sure.  Someone recently posted some information about Singulair--I
believe that one tablet has milk protein in it, and another doesn't (between
5 and 10 mg).  Some people on the list complain about this.
Also, corn is a pretty common allergy, so consider that too.
Also, make sure! you have a list of all the other names for milk--there are
at least 15 or so.  There's one available from this list.
Don't have much time right now but I'm sure others will chime in.
Christy