A milk allergy is an immune system reaction to one of the proteins in milk, such as casein or whey. It is not the same as a lactose intolerance, which is a digestive issue caused by a deficiency of the enzyme lactase. Milk allergy can cause a range of symptoms, from mild to severe, including hives, itching, swelling, stomach cramps, diarrhea, and even anaphylaxis. In severe cases, milk allergy can...More