Food allergies have become a major concern with parents, health practitioners and school administrators. However, the estimates of prevalence of allergies varies widely.
A commonly accepted definition is an “adverse immune response that occurs reproducibly on exposure to a given food and is distinct from other adverse responses to food, such as food intolerance, pharmacologic reactions, and toxin-mediated reactions.”
However, most people are not going to make such a fine distinction between food allergy and food intolerance. Non-celiac gluten-sensitivity (NCGS) does not cause an IgE response so with this definition it not classed as a food allergy.
Dairy, in particular, cow’s milk and gluten, wheat and grains are commonly avoided as a result of concerns about food allergies.