Food intolerances are not allergies

A food allergy is an immune reaction, mediated by IgE antibodies, following the swallowing of a specific food or substances within it.

Once the antibody is exposed to the allergenic food, histamine is released, which causes most of the symptoms related to allergy, such as:

Hives and other skin conditions
Mucosae oedema
Nausea and vomit
Anaphylaxis in severe but rare cases

All the afore-mentioned symptoms usually occur right after the food has been swallowed.

Food intolerances are not immediate IgE phenomena.

An intolerance is a reaction originated by one or more foods, which cannot be completely digested. Symptoms may appear even days after the food has been eaten and their intensity is related to the quantity of food swallowed.