How does milk allergy differ from milk intolerance?

Immune mechanism: Reactions to foods can be from immune reactions, or from other mechanisms. Allergy is an immune reaction against the food. An intolerance might happen when you lack an enzyme to digest the food, such as with lactose (milk) intolerance. Generally speaking, intolerances are milder, not life-threatening, and cannot be diagnosed by typical allergy scratch or prick tests.

Milk allergy: In milk allergy, the doctor is able to find antibodies to milk proteins. In milk intolerance, a cause for the symptoms is not obvious. Milk intolerance can often be due to lacknofnthe digestive enzyme for milk sugar. The enzyme is called lactase, the sugar lactose. But sometimes milk intolerance occurs in the absence of allergy or enzyme deficiency and we can't explain it.