The Food allergies occur with an immediate reaction to the food ingested or almost regardless of the amount ingested and only occur in some people. In this mechanism come into play antibodies type immunoglobulin E (Ig E). Normally the foods we eat do not cause allergic reactions, because during embryonic development establishes a mechanism of "tolerance." In food allergies errors occur in this system of control by the immune system, which is responsible to recognize foreign substances (antigens) and to react against them. The characteristic of allergic subjects is to produce as a response to a stimulus a greater amount of Ig E than in non-allergic and to continue to produce more for a certain period of time.
Among the foods that most commonly cause allergy are:
- cow's milk (the allergy is quite common in children under a year and often resolves within 3 years of the child's life)
- the egg (the egg white is the most allergenic of the yolk, and cooked egg is less allergenic than raw)
- peanuts (contrary of allergy to milk and egg this does not dim with age)
- vegetable
- apples and Prunoidee (plums, apricots, peaches and cherries) there is often a cross-reaction with some pollen (birch and Composite) and with latex
- fish
- shellfish
- clams
- pork
The analysis for the diagnosis of food allergy include skin tests (prick test), which put in contact with the various allergen extracts the skin of the subject and the research of circulating serum Ig E (RAST).
Drug therapy is needed to control the symptoms, of course, the more severe anaphylactic shock, in this case, administer adrenaline subcutaneously and drugs acting on specific symptoms. Antihistamines are used in less severe forms. The treatment of food allergy is mostly diet.
As for the diagnosis of food intolerance are circulating throughout a series of non-conventional tests (Vega test, Dried tests, hair analysis and so on ...) which do not have a recognition by the official medicine and which are unreliable , as well as expensive! Give many false positives, forcing a little varied diet and can cause deficiencies of certain nutrients. In case of suspected intolerance can be useful to exclude the offending foods and then reintroduce them one at a time.
The only real enzymatic intolerances are lactose intolerance (lactase deficiency), fauvism (glucose 6 phosphate dehydrogenate) and phenylketonuria (deficiency of phenylalanine hydroxyls).