The most recent scientific data show that food allergy affects about 2-4% of the general population. Amongst the paediatric age group there is a higher incidence with 6-8% of babies and 3-5% of children up until 8 years of age being affected. We use the term food allergy to describe an immunological reaction towards proteins which are normally tolerated. IgE-mediated food allergies are caused by IgE antibodies while non-IgE mediated food allergies are not caused by such antibodies.

Intolerance is due to a lack of enzymes, to pharmacological mechanisms or to toxins (e.g. intolerance to lactose). While it is true that any food can potentially act as an allergen for the organism, it has been seen that in most cases allergic reactions are caused by certain foods in particular: cow's milk, egg, soya, wheat, fish, peanuts (or other nuts), crustaceans. European law dictates that such foods should be labelled as potentially dangerous in the list of ingredients of all food products.

The symptoms of food allergy are:
dermatological symptoms (rashes, angioedema, atopic dermatitis),
gastrointestinal symptoms (like the oral allergy syndrome, colic, nausea, vomit, diarrhoea, abdominal pain);
respiratory problems (rhinitis, oedema of the glottis, asthma);
In some cases there is a sudden and contemporaneous involvement of the skin, the gastrointestinal system, the respiratory system, and the circulatory system which together constitute an anaphylactic shock that represent most serious manifestation of food allergies.

It is important to bear in mind that food allergies are the only allergies from which you can completely recover. A timely diagnosis and correct management of the diet by the patient even allows adults to overcome the complaint. Even for those allergies which are more serious and life-persistent, such as peanut allergy, there are research programs in progress which will allow the realization, in the near future, of actual vaccines for all foods which cause allergies.