Oh, I can so relate!! Each of my 3 kids demonstrated milk allergies by 3 weeks. Eliminating all milk products got us through breastfeeding without too many flare ups. (I breastfed 2 years with each child). But my middle child had more allergies: soy, "too much" eggs, "too much" corn, "too much" citrus, "too much" strawberries. And my youngest child is also allergic to rice, artificial colors, almonds, "too much" soy. My oldest is also allergic to dust/mold (sinus infection his 1st 18 months -- until we moved). (... I think I covered all of them ...)
As you can see, it is not just one thing for us. Often a food/allergen will be okay by itself, but if added to other allergens (which also may be okay alone) an allergic reaction will occur. It's as if the "allergy bucket" overflows.
Because of the constant tummy aches I finally took my middle child (then age 4) to an allergist in Lake Stevens for testing -- bloodwork, not scratch testing. That's when we found out about the soy and corn. Now, at age 10, he can have the occasional little bit of soy or citrus or ??? with little to no reaction.
For eczema flare ups I use Bag Balm. Yep, the stuff for cow's udders in the green tin. (I get it from my local feed store, but I've seen it at Fred Meyer also.) It works great to stop the itching and it's non-toxic! Also good for diaper rash, cracked nipples and miscellaneous injuries.
Good luck! Let me know if I can be of any help!