food allergy

Pseudo-allergic reactions

Food intolerance or allergy?

Since a "simple" food intolerance can cause some typical symptoms of food allergies - such as nausea, vomiting, diarrhea and abdominal cramps - many people tend to confuse the two terms. In reality, food intolerances, unlike allergies, are always linked to a dose, which every individual should know to avoid overtaking it.

Another fundamental difference is that in food intolerance the immune system is never involved, even if in many cases the symptomatology, in some respects similar to that of allergies, leaves us to think otherwise.

In most cases, food intolerance is linked to enzymatic dysfunctions, therefore to the lack or lack of enzymes needed to digest certain substances; particularly known is the deficiency of lactase, a protein necessary for the digestion of milk sugar and whose deficiency leads to widespread lactose intolerance.

Differences between allergies, food intolerances and pseudo-allergic reactions

Food allergy *:

symptoms unleashed within minutes of taking a specific food or group of foods (from 2-3 'to 30-120') sometimes even in a violent way. Food allergy is immunologically mediated and the symptoms are triggered by the intake of even small amounts of the responsible food.

Food intolerance:

symptomatology linked to the quantity of the food taken and determined by particular molecules present in food or by dysfunctions of the digestive system (enzyme deficiencies). The symptoms are often similar to those of allergy but differ because they do not involve the immune system and have a late appearance, sometimes even a few days after intake. Examples are lactose intolerance and favism.

Pseudo-allergic reactions:

they are given by foods rich in histamine and / or tyramine or containing liberating histamine substances. Taken in large quantities can cause symptoms similar to those of allergy.

(*) The terms food allergy and food hypersensitivity can be used as synonyms

Pseudo-allergic reactions

Pseudo-allergic reactions have all the characteristics of allergies, except the involvement of the immune system. They are caused by foods rich in tyramine or histamine, or able to stimulate the body's release of histamine. The release of these chemical mediators represents the final point of the cascade of allergic reactions and is responsible for the typical manifestations in the skin, respiratory, gastrointestinal, etc.

Strawberry intolerance belongs to the category of pseudo-allergic reactions, because this food, similar to tomatoes and crustaceans, stimulates the release of histamine. Once ingested, these foods, while being devoid of allergenic power, can mimic an allergic reaction from a symptomatic point of view. These manifestations are controlled by antihistamine therapy and do not cause concrete dangers to the health of the individual (which are instead typical of a real food allergy).

Consuming this type of food may appear skin rashes (red spots on the skin, itching) but, once the administration has ceased, the symptoms rapidly regress. The amounts capable of triggering the allergic reaction vary from person to person in relation to individual predisposition.

Histamine and / or tiramine rich foods: fermented cheeses, aged cheeses, pork liver, sausages, blue fish (sardines, mackerel, anchovies), tuna, salmon, herring, tomatoes, spinach, fermented drinks.

It should be noted that the concentration of histamine and tyramine is inversely proportional to the freshness of the fish (when a few days old fish is consumed it is easier to run into unpleasant pseudo-allergic problems).

Foods containing liberating histamine substances: shellfish and seafood, some types of fish and canned foods, egg whites, chocolate, tomatoes, strawberries.