5 yr old breaks out in hives within minutes of consuming milk - benedryl fixes it - but can eat any milk containing product (yogurt, cheese, ice cream, baked goods) without issue. why the difference?

Protein inactivation: Baking or cooking milk inactivates many of the proteins that cause allergic reactions. In todays markets, there are many milk substitutes that you can try. Start with lactose free milk, then A3 milk, then milk alternatives (soy, coconut, oat). Remember that consuming the same allergen over and over can cause an escalation of the allergic reaction. Don't feed him regular milk.

Food panel : A food allergy panel test may be useful in identifying other food allergies. There may be multiple food allergies present in varying presentations which may contribute to the hives reaction. Please follow up with your physician or have a virtual consultation with Healthtap and testing ordered as indicated.