Questions re. Baby reacting to eggs and dairy

Hi Ladies, DD (now 9 months) has reacted to both eggs and the skim milk powder in the "just add water" rice cereal. Reaction has been almost immediate facial hives that lasted about half an hour. Her family doctor didn't have too much advice except to avoid and has refered her for allergist testing. Unfortunately, our appt for allergy testing is not until the end of May. Anyone have similar experiences? Also, She is breast fed now but I was contemplating introducing a bit of formula as I may be returning to work shortly, but don't know what's safe. Should I try yogurt and other forms of dairy?