Quite often, food intolerance proceeds through the mechanisms of pseudo-allergic reactions, according to the online publication for girls and women from 14 to 35 years old Pannochka. net The development of pseudo-allergic reactions to food products is based on the non-specific release of mediators (mainly histamine) from allergy target cells.

False food allergy, proceeding through the mechanisms of pseudo-allergy, differs from other reactions associated with food intolerance in that the same mediators are involved in its implementation as in true food allergy (histamine, leukotrienes, prostaglandins and other cytokines), but.

This is possible with the direct action of antigens of the food substrate (without the participation of allergic antibodies) on target cells (mast cells) and indirectly, with the activation of a number of biological systems by the antigen (kinin, complement system). Histamine is the main mediator in false food allergies..

It is known that the development of a pseudo-allergic reaction to food provokes a number of factors: excessive consumption of foods rich in histamine, tyramine, histamine liberators; excessive formation of histamine from the food substrate; increased absorption of histamine in functional insufficiency of the mucous membrane of the gastrointestinal tract; increased release of histamine from target cells; violation of the synthesis of prostaglandins, leukotrienes.

An increase in the level of histamine in the blood with a false food allergy can be not only with increased intake or formation of it in the intestinal lumen, but also with a violation of its inactivation.

Thus, in inflammatory diseases of the gastrointestinal tract, the secretion of mucoproteins involved in the inactivation of histamine decreases.. In some liver diseases, the formation of monoamine oxidase is sharply reduced, which also leads to an increase in the level of histamine in the blood..

Most often, pseudo-allergic reactions develop after eating foods rich in histamine, tyramine, histamine liberators. Table. 36. 1 shows the most common high histamine foods.

Table 36. Foods high in histamine Foods Histamine content, mcg/g Fermented cheeses Up to 1300 Fermented wines 20 Sauerkraut 160 mg/kg (serving 250 g - 40 mg) Dried ham and beef sausages 225 Pork liver 25 Canned tuna 20 Canned smoked anchovy fillet 33. may occur with the use of foods rich in tyramine, excessive synthesis of tyramine by the intestinal flora, deficiency of platelet monoamine oxidase, leading to incomplete destruction of endogenous tyramine.

The cause of pseudo-allergy can be foods high in vasoactive amine - ?-phenylethylamine (tyramine,): foods that are fermented (for example, cheeses, cocoa beans), red wines (table. 36. 2). Just 3 mg of this substance can cause headaches in migraine sufferers..

Table 36. Foods high in tyramine Products Tyramine content, mcg/g Brewer's yeast 15000 Pickled herring 3030 Cheddar cheese 1466 French cheeses:.

camembert 20-86 brie 180 griart 516 Note: chocolate is rich in methyltyramine (1 mg in 15 g of chocolate).

Histamine-releasing activity has: egg white (contains ovomucoid), shelled marine animals, strawberries, tomatoes, chocolate, fish, ham, pineapples, ethanol, peanuts, cereals.

In recent years, there has been an increase in pseudo-allergic reactions to impurities with high physical and biological activity (pesticides, fluorine-containing, organochlorine compounds, sulfur compounds, acid aerosols, microbiological industry products) that contaminate food products..

Often, the cause of the development of a pseudo-allergic reaction to food products is not the product itself, but various chemical additives introduced to improve taste, smell, color and ensure shelf life.. The category of food additives includes a large group of substances: dyes, flavors, antioxidants, emulsifiers, enzymes, thickeners, bacteriostatic substances, preservatives.

Among the most common food colorings, tartrazine is noted, which provides an orange-yellow color to the product.; sodium nitrite, which keeps meat products red.

For canning, monosodium glutamate, salicylates, in particular acetylsalicylic acid are used..

The mechanism of action of food impurities and food additives can be different:.

- induction of pseudo-allergic reactions due to the direct action of drugs on sensitive target cells of allergy, followed by non-specific liberation of mediators (histamine);

- a violation of the metabolism of arachidonic acid (tartrazine, acetylsalicylic acid), while cyclooxygenase is inhibited and excessive formation of leukotrienes occurs, which can cause smooth muscle spasm (bronchospasm), mucus hypersecretion, increased vascular wall permeability, and a decrease in coronary blood flow;

- activation of complement along an alternative pathway by a number of food additives, while complement activation products have the effect of allergy mediators;

- inhibition of the enzyme activity of monoamine oxidase.

The development of a true food allergy with the formation of antibodies of the IgE class. In particular, this mechanism has been proven in relation to the azo dye tartrazine, which plays the role of a hapten and, forming complexes with serum albumin, becomes a full-fledged antigen..

The division of food allergies into true and false is very conditional.. One patient may develop reactions to food due to the participation of both specific immune reactions and pseudo-allergic ones (Table. 36. 3).

Table 36.

Additional differential diagnostic signs of true allergic and pseudo-allergic reactions to food Symptom True allergic reactions Pseudo-allergic reactions Onset of the disease Usually in childhood More often after 40 years Concomitant diseases of the digestive system Often Almost always Blood eosinophilia Often high May be moderate Eosinophils in fecal mucus May be in significant quantities.

Pseudo-allergic reactions to food differ in the polymorphism of skin rashes: from urticaria (10-20% of patients), papular (20-30%), erythematous, macular (15-30%) to hemorrhagic and bullous rashes.

Skin manifestations in any form of food allergy are often accompanied by itching.. Along with skin manifestations, there is a decrease in appetite, poor sleep, asthenoneurotic reactions..

Baranovsky medbe. en.