Food allergy

Food allergy is very hard to tolerate because the allergen, entering the body, has a strong depressant effect, in practice, on all organs and systems. And the time spent searching for an allergen leads to a prolongation of the allergic process, which in turn leads to the adherence of many side diseases. Therefore, it is very important to know the symptoms of food allergies and to pay attention to any of their manifestations.

The earliest manifestations of allergic reactions are observed in the first year of the child's life and are related either to inaccuracies in the mother's diet, or to a transition to a new, for the child, type of food. The food allergy develops both on artificial milk mixtures, and on natural cow milk. When introducing complementary foods, you need to be careful with carrots, eggs, many berries. A special highly allergenic group is citrus fruit.

[1], [2], [3], [4], [5], [6]

Causes of food allergy

Food allergies are caused by substances with high allergenic properties, and this can be: animal proteins and vitamins, especially the C group. All products containing the listed components are automatically ranked as a "risk group". Fish, caviar and seafood, egg and milk proteins, all red berries, citrus fruits, and even carrots can fall under the term "allergen". For a weakened organism, with reduced protective functions and a predisposition to allergic reactions, an allergen can serve anything, even rye bread. Therefore, to any case of manifestation of such a state as food allergy should be approached individually and in a complex manner.

Food allergies should be distinguished from non-immune reactions to food (for example, lactase intolerance, irritable bowel syndrome, infectious gastroenteritis) and reactions to food additives (eg, sodium glutamate, meta-bisulfite, tartrazine) that cause most of the food reactions. The specific gravity is from less than 1 to 3% and varies depending on geography and detection methods; patients often confuse intolerance with allergies. Normal digestion prevents the development of food allergy symptoms in adults. Any food or food supplement may contain allergens, but most often in infants and young children allergies are caused by milk, soy, eggs, peanuts, wheat, and nuts and seafood are the most common allergens in older children and adults. There is a cross-reactivity between food and non-food allergens, and sensitization can occur not by an enteral route. For example, patients with oral allergy (pruritus, erythema, edema of the oral mucosa after eating fruits and vegetables) could be sensitized with pollen; children with peanut allergy may be sensitized with creams, used in the treatment of rashes and containing peanut butter. Patients with an allergy to latex are usually allergic to bananas, kiwi, avocados or combinations of these products. Allergy to latex dust in food left by latex workers gloves is easily confused with food allergy.

In general, food allergy is mediated by IgE, T-lymphocytes or both. IgE-mediated allergy (eg urticaria, asthma, anaphylaxis) has an acute onset, usually occurs in infancy, is most common in individuals with a family history of atopy. T-cell-mediated allergy (for example, food protein gastroenteropathy, celiac disease) manifests gradually and proceeds chronically. Allergy mediated by IgE and T-lymphocytes (eg, atopic dermatitis, eosinophilic gastroenteropathy), has a delayed onset and proceeds chronically. Eosinophilic gastroenteropathy is an unusual disorder that is accompanied by pain, spasms, diarrhea, eosinophilia in the blood test, eosinophilic infiltrates in the intestinal wall, loss of proteins and atopic disorders in the anamnesis. Rarely, infants have lgG-mediated allergies to cow's milk, resulting in pulmonary hemorrhages (hemosiderosis of the lungs).

[7], [8], [9], [10]

Symptoms of food allergy

Symptoms and objective data are very diverse depending on the allergen, mechanism and age of the patient. The most common manifestation in infants is atopic dermatitis alone or with symptoms of gastrointestinal tract damage (nausea, vomiting, diarrhea). In older children, signs change, and they react more to inhalant allergens with symptoms of asthma and rhinitis (atopic flow). By the age of 10, respiratory symptoms rarely appear in patients after ingestion of allergens with food, even if skin tests remain positive. If atopic dermatitis persists or first appears in older children and adults, then obviously it is not IgE-mediated, even if the serum IgE level in patients with pronounced atopic dermatitis is higher than those who have it no.

In older children and adults receiving allergens with food, there is a tendency to more severe reactions (for example, exfoliative urticaria, angioedema, even anaphylaxis). In a small number of patients, food (especially containing wheat and celery) is the initiating element of anaphylaxis immediately after they are taken; the mechanism of this phenomenon is unknown. In some patients, migraine induced or intensified by food allergens is observed, which is confirmed by blind oral provocative tests. Most often accompanied by food allergy cheilitis, aphthous lesions, pilorospazm, spastic constipation, itching in the anus, perianal eczema.

The appearance of the first signs of food allergy begins within a few minutes after the ingress of the allergen into the digestive system. It often happens that the delay in the symptomatic pattern is stretched for several hours. Although much more often, a food allergy manifests itself instantly. Runs on several principles:

• skin dermatitis or urticaria;
• rhinitis;
• intestinal dyspeptic disorders;
• edema of Quincke;
• anaphylactic shock.

The last two principles of rapid flow, in cases of food allergy, are very rare, only with a greatly weakened child's body. Most often, food allergies give skin reactions and disorders from the gastrointestinal tract.

There is a complex form of food allergy - a cross, which occurs immediately on several allergens, belonging to different groups. For example, there may be a food allergy to carrots, proceeding according to the principle of dermatitis. To remove the itching and rash, grass is used, in the form of a decoction, which is added during bathing. As a result, more and more allergic symptoms are obtained. This is a variant of the development of cross-allergy. In this example, allergens are carrots and turn.

Diagnosis of food allergy

It is very useful for pregnant women to take the habit of keeping a food diary, which will reflect the main foods taken for food throughout pregnancy. With the birth of a child, records of the mother's diet continue, and data on those foods that are beginning to be included as complementary foods for the child are also added there. The presence of such a diary will greatly facilitate the situation, if there is a food allergy and establish an allergen is not difficult. In the presence of a diary or without it, for express diagnosis, rapid tests are conducted, allergological anamnesis is collected, several allergological tests are taken.

Severe food allergy is more easily diagnosed in adults. In the absence of obvious signs, as well as in most children, diagnosis is difficult, and such digestive disorders must be differentiated with functional abnormalities of the digestive tract.

[11], [12], [13], [14], [15]

Methods of treatment of food allergy

The main goal of therapeutic measures is to eliminate the cause, which results in food allergy and further exclusion of this type of allergens in the body. A course of treatment with antihistamines, with the simultaneous use of sorbents, which help the rapid removal of allergic toxins from the body, at the same time increase the effect of antihistamines. 

Strict diet, excluding the slightest content of products belonging to the "allergenic risk group". Food allergy is also treated with immunostimulating drugs, which are prescribed to improve the body's resistance.

When a food allergy is suspected, the relationship of the existing symptoms to food intake is assessed using dermal or lgE-specific radioallergosorbent tests. Positive results of the samples do not yet prove a clinically significant allergy, but negative results exclude it. If the answers to skin tests are positive, a certain product is removed from the diet; if the symptoms begin to fade, the patient is advised to repeat the intake of this food (preferably in a double-blind test) for the re-emergence of allergy symptoms.

An alternative to skin tests is the removal of foods, according to patients who cause allergic symptoms, the appointment of a diet consisting of relatively non-allergenic products and the exclusion of common allergens. No other products can be consumed, except recommended. Clean products should be used. Many commercially prepared foods contain unwanted substances in large quantities (for example, commercially available rye bread contains wheat flour) or trace amounts: flours or fats for baking or roasting, making it difficult to identify undesirable products.

Permitted products in elimination diets ¹

Product	Diet № 1	Diet №2	Diet №3
Cereals	Rice	Corn	-
Vegetables	Artichokes, beets, carrots, lettuce, spinach	Asparagus, corn, peas, zucchini, green beans, tomatoes	Beets, lima beans, potatoes (white and sweet), green beans, tomatoes
Meat	Mutton	Bacon, chicken	Bacon, beef
Flour products (bread and biscuits)	Rice	Corn, 100% rye (regular rye bread containing wheat)	Lima beans, potatoes, soybeans
Fruit	Grapefruit, lemon, pear	Apricot, peach, pineapple, plum	Apricot, grapefruit, lemon, peach
Fats	Cotton, olive oil	Corn, cotton	Cotton, olive
Beverages	Coffee black, lemonade, tea	Coffee black, lemonade, tea	Coffee black, lemonade, juice of allowed fruits, tea
Other products	Reed sugar, gelatin, maple sugar, olives, salt, tapioca pudding	Reed sugar, corn syrup, salt	Reed sugar, gelatin, maple sugar, olives, salt, tapioca pudding

¹ Diet No. 4: If the patient follows one of the proposed diets, and the symptoms do not disappear, then following this diet is questionable, and it is necessary to limit oneself to elementary products.

If no improvement is observed within one week, another diet should be used. If the symptoms go away, one new product is added in large amounts for more than 24 hours or until the symptoms resume. In another method, the patient takes a small amount of the test new product in the presence of a doctor, and the patient's reaction is recorded. Reinforcement or relapse of symptoms after taking a new product is the best confirmation of the allergic process.

When assessing the effectiveness of the elimination diet, the physician should consider that food sensitization may disappear spontaneously. The effectiveness of oral desensitization has not been proven (complete removal of the allergenic product for a while, the subsequent administration in a very small amount with a daily slight increase in the dose), nor sublingual tablets with food extracts. Antihistamines are of limited importance, with the exception of acute generalized reactions with urticaria and angioneurotic edema. With success, kromolin is administered orally. Long-term treatment with glucocorticoids is used for symptomatic eosinophilic enteropathy. The use of humanized monoclonal IgG antibodies directed against the NEZ region of the IgE region shows good results in the treatment of allergy to peanuts.

Prevention of food allergy

There is no such complex of measures, strictly adhering to which, you can permanently protect yourself from such an unpleasant state as food allergy. But there are basic rules for maintaining a healthy lifestyle, observance of which contributes to the fact that the body "accustoms" to an independent struggle with any negative factors coming from the external environment. From early years it is useful to harden, play sports and eat not only meat, but vegetable dishes, among which much attention should be paid to fresh vegetables. Diversify your diet with porridges from different cereals and cereals, take vitamin complexes during the off-season - that's all you need to get the body all the necessary tools, both for building strong walls of organs, vessels and tissues, and for resisting threats.

Food allergy, in the light of low environmental performance and high levels of chemicals in food, is, alas, not rare. However, with careful consideration of your health, timely access to doctors, you can not only avoid serious manifestations of any allergic reactions, but also completely avoid meeting them.