Pseudoallergic reactions
Food intolerance or allergy?
Since a “simple” food intolerance can cause some typical food allergy symptoms — 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 exceeding it. Another fundamental difference is that in food intolerance the immune system is never involved , even if in many cases the symptoms, which in some respects overlap with those of allergies, suggest the opposite. In most cases, food intolerance is linked to enzymatic dysfunctions, therefore to the deficiency or lack of enzymes necessary to digest certain substances; particularly well 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 pseudoallergic reactions |
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| Food allergy*:
symptoms triggered within a few minutes of eating a certain food or group of foods (from 2-3′ to 30-120′), sometimes even violently. Food allergy is immunologically mediated and the symptoms are triggered by the intake of even small quantities of the responsible food. |
Food intolerance:
symptoms linked to the quantity of food consumed and determined by particular molecules present in foods or by dysfunctions of the digestive system (enzyme deficiencies). The symptoms often overlap with those of allergies but differ because they do not involve the immune system and appear late, sometimes even a few days after intake. Examples of this are lactose intolerance and favism . |
Pseudoallergic reactions:
are given by foods rich in histamine and/or tyramine or containing histamine-releasing substances. Taken in large quantities they can cause symptoms similar to those of allergies. |
| (*) The terms food allergy and food hypersensitivity can be used synonymously | ||
Pseudoallergic reactions
Pseudoallergic reactions have all the characteristics of allergies, except the involvement of the immune system. They are caused by foods that are in themselves rich in tyramine or histamine, or capable of stimulating the release of histamine by the body. The release of these chemical mediators represents the final point of the cascade of allergic reactions and is responsible for the typical manifestations at the skin, respiratory, gastrointestinal level, etc. Strawberry
intolerance belongs to the category of pseudoallergic reactions, because this food, similarly to tomatoes and shellfish , stimulates the release of histamine. Once ingested, these foods, despite having no allergenic properties, 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 individual’s health (which are instead typical of a real food allergy). By consuming this type of food, skin rashes may appear (red dots on the skin , itching ) but, once administration is stopped, the symptoms quickly regress. The quantities capable of triggering the allergic reaction vary from person to person in relation to individual predisposition.
| Foods rich in histamine and/or tyramine: fermented cheeses , mature cheeses , pork liver , sausages , oily 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 you consume fish that is a few days old it is easier to run into unpleasant problems of a pseudo-allergic nature). |
