What's the difference between IgE-mediated allergies and Non-IgE mediated food allergies?

My grandaughter was born 1/24/06 she has severe acid reflux and milk allergys she is currently takeing zantac and prevacid and neocate formula, but ins is refusing to pay for formula saying she is not sick, what can we do as this is 143.00 for 4 cans and she is doing a can in abt 2 days. she weighed 8 15 and now is only 10.5 we are running out of options can you direct us what to do?

My son has MSPI. He also has had an allergic reaction to every solid food that we have given him (carrots, sweet peas, green beans, bananas, applesauce, sweet potatoes). His bloodwork came back positive or borderline for milk, soy, oats, wheat and many others. The only thing he can tolerate besides his Neocate formula is Beechnut rice. Are there other baby products he can eat that are milk, soy and gluten free? I am concerned that he needs to be starting solids to develop his eating ability with texture.

My son is 4 years. he is allergic to dairy milk and soy. He has been on Nutramagen until now and we would like to try Neocate. He does not have impairment of the gastrointestinal tract but has severe ezcema, so what is the right Neocate product you recommend.