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Filtrum / Useful Materials / Food allergy

Food allergy

  1. Classification
  2. Causes of allergies
  3. Symptoms of allergy
  4. Treating allergies

Food allergy

Food allergy is a body modified immune response to certain components contained in food. Often the disorder affects children, especially babies. In adults, food allergy is much less common. Even a small amount of allergen can threat human life.


Food allergies can be indicated in the ICD by one of the following codes:

  • L 20.8 - other atopic dermatitis (skin inflammation caused by an allergen);
  • L 27.2 - dermatitis due to feedings;
  • L 50 - hives;
  • T 78.1 - other manifestations of a pathological reaction to feedings.

With food allergies, the reaction is caused by high-quality and fresh products, which are completely harmless to other people. Usually it causes skin manifestations, less often the symptoms occur in the digestive system. With a severe allergic reaction, dangerous anaphylactic shock can happen, but this kind of reaction is less provided by food allergies.

Food allergies can be caused by abnormal reactions of immune cells, formation specific antibodies to food substances (reactans, or immunoglobulins of E class), as well as their combination. Therefore, the classification of food allergies includes:

  • reactions mediated by forming reactans (urticaria, rhinitis, conjunctivitis, asthma attacks, intestinal distress, anaphylactic reactions);
  • mixed variant (dermatitis, gastrointestinal disorders);
  • manifestations of cellular pathology (inflamed intestine).

Allergy causes

Food allergy is caused by proteins coming in the adult or childish body with food, less often by protein-like substances - haptens. These protein molecules have sites activating a protective immune response in people featuring genetically determined immunity changes. The stomach and intestine states also matter: if they are disordered, the probability of contact of the allergen with immunocompetent cells or antibodies increases, their sensitivity increases.

Food allergies in children

Food allergies in children

In many cases, childish allergic reactions are the result of mother`sl malnutrition during pregnancy or lactation. For example, excessive having eggs during pregnancy can lead with a high probability to appearing baby`s allergy to this product.

However, the true cause of allergy is genetic impairment of immunity, which can be inherited or originated spontaneously.

Most often, children's food allergies are provoked by the following factors:

  • insufficient breastfeeding, early turn to mixtures containing cow's milk protein;
  • prematurity;
  • diseases of the gastrointestinal tract, biliary tract or liver.

Allergy to cow's milk protein is observed in 2 - 3% of babies. By the age of 5, 80% of these patients do not suffer from the allergy, and by the age of 6 only 1 out of 100 children can not tolerate cow's milk.

Childish food allergy appears at least once with a probability of 17% during the first years of baby`s life.

Allergies in adults

Allergies in adults

Adult people suffer from allergies for various reasons too. Some of them are common for adults and children:

  • genetically mediated immunity disorders;
  • inflamed gastrointestinal tract letting unsplit products penetrate through the ontestine walls;
  • disordered pancreas slowing substance absorption, as well as dyskinesia of bile ducts or intestines;
  • improper diet provoking gastritis and other stomach disorders (this is the cause of both normal allergies and fake allergies.

Some people experience allergic reactions to certain food supplements. These substances are developed to improve product taste, color and aroma, as well as to increase shelf life. Allergy sufferers get a lot of trouble from tartrazine, a dye making products of yellow-buffy color. The black list also contains sodium nitrite added to meat and sausage products to provide them with appetizing pink and red color. Among the preservatives, glutamate sodium and salicylates are especially marked out. The reaction to supplements in people already suffering from food allergy is observed in 5-7% of cases, and among healthy ones, the numbers are only 1 - 2 people out of 1000.

Allergetic products

Among food products, only salt and sugar are not allergens. The rest meal is capable of causing allergies, especially in those predisposed. Let's discuss products that are already well researched and are on the list of quite powerful allergens.

Cow's milk

This is one of the most famous allergens. The milk composition includes about 20 types of protein, each of them has a certain ability to cause allergies. In the process of boiling, some of these proteins split, but this does not apply to all types. However, beef itself is very rarely included in the list of allergens in those who are acutely sensitive to the consumption of cow's milk.

Chicken eggs

This is also a fairly common allergen. In medical practice, there are cases when even one chicken egg eaten led to anaphylactic shock and other serious consequences. The fact is that the egg proteins are able to penetrate intestinal walls in an unchanged form.

The egg protein and yolk feature different antigenic qualities, so some people can easily have protein, but experience allergy attacks because of yolk eaten, and vice versa. If processed, the egg protein antigenicity lowers.

The allergic reaction caused in people with chicken egg eaten is applicable to duck or goose eggs too, so replacing one product with another does not help in this case. Moreover, in people who are allergic to chicken eggs, often experience allergy to chicken.

The reaction to eggs disappears in about 10% of children over the years.


The fish has powerful antigenic and histamine-releasing properties. Not only having fish, but even inhaling its smell during cooking can be dangerous. People featuring high degree of reaction to fish, as a rule, are intolerant of absolutely any fish sorts and species. In other cases, the allergy can only spread to one or more species, while a person can have painlessly the rest of fish.

Crustaceans (crayfish, crabs, shrimp, lobsters)

Crustaceans feature so-called cross-sectional antigenicity: if a person has a reaction to one type of crustacean, then all other species should be excluded from the diet. This also includes freshwater crayfish daphnia, which is often added to dry food for aquarium fish. Daphnia is also capable of causing an allergic reaction like difficult breathing.

Pallergic predisposition to seafood and fish lasts the whole life and can be accompanied by anaphylactic reactions even in case of insignificant contact with the allergen.

Wheat and soybeans

These products are also among the most known allergens.


The meat contains a large amount of protein, however, this product provokes allergies infrequently. In this case, some types of meat and poultry have a higher antigenicity than others do. For example, peopl featuring a reaction to beef can have lamb, pork or chicken sometimes.


Cereals (wheat, rye, maize, rice, oats and others) can cause a mild allergic reaction, but if applied, they rarely lead to serious consequences. Half of children has no reaction to cereals to 5 - 6 years old.

Vegetables, fruits, berries

There are pretty numerous allergens in this category of food. The most powerful reaction is caused by citrus fruits (orange, grapefruit, lemon), strawberries and wild strawberries. Meanwhile, a person usually experiences the same reaction to all fruits from the same family.

But there are also atypical cross-reactions. In particular, people who are allergic to pollen of plants of the birch family (pollinosis), can not often eat apples and carrots belonging to completely different families. Reducing antigenic vegetable, fruit and berry properties is provided with thermal treatment.


Many people are sensitive to nuts, and in some cases the reaction to this product can be quite strong. If there is an allergy to one kind of nuts, a person usually does not deny himself the use of other species, although sometimes the reaction may be the same to all products from this category. Nut intolerance is very common in people featuring allergy to pollen hazel. Peanut is a very strong allergen causing anaphylactic reaction very often. Only 20% of children stop experiencing allergy to this product over the years.


It is believed that chocolate causes a rather strong allergy, but in fact this product features a low antigenicity. It is able to cause only a slight slow reaction, which is also a cocoa feature.

Symptoms of an allergy

The manifestations of food allergies vary depending on the age and immunity of the child. Below there is a list of the main ailments that indicate allergies occured:

Symptoms of an allergy

  • skin rashes, as well as itching, swelling, or burning;
  • oral cavity mucosa edema;
  • allergic rhinitis (manifested by nasal congestion, sneezing and mucous discharge);
  • coughing (sometimes with sputum);
  • choking (caused by laryngeal edema);
  • watery and reddened eyes;
  • nausea and vomiting, diarrhea with blood and mucus;
  • painful abdomen

A rash appeared in person experiencing food allergies usually has the nature of urticaria - small numerous spots on the reddened skin featuring swelling and itching.

In infants, food allergy features a number of additional symptoms caused by concomitant atopic dermatitis:

  • diaper rash appeared;
  • skin got red in the anus area, which increases after feeding.

As a rule, manifestations of allergies disappear almost without a trace if a special diet is observed.

Лечение аллергии

Treating allergies

Treatment of food allergies primarily involves following proper diet. The sufferer should abandon the products and dishes containing the allergen to the fullest. During the diet, you can slowly, but reliably overcome allergies, but special diet should be followed and after your condition improves. Feeding mothers need especially attentively consider the issue of diet.

In general, there are two types of diets against food allergies:

  1. Nonspecific diet (involves rejection of all products that can cause allergies). This kind of diet should be adhered to at the initial stage of diagnosis, when it is still unknown exactly what caused the allergy;
  2. Exclusive diet (complete rejection of the product provoking reaction, even in the smallest amounts).

Diet can act as the only way to prevent allergies, and in this case it applies to both the adult and the baby. Depending on the age of the patient and course of the disease, it takes from one to four weeks to fight.

If a child features a food allergy to cow's milk protein, it has been proved that it should not be fed with goat's milk. It is necessary to use only ready-made mixtures based on highly hydrolyzed milk protein or amino acids. In 90% of children featuring milk allergy, these mixtures do not cause pathological reactions.

Even if the allergy is manifested in an easy form, and the sufferer`s health is not threatened, he/she is recommended to consult a doctor anyway. Symptoms of food allergy require the following medicines prescribed:

  • sorbents, for example, Filtrum (stimulating removal of allergens from the body);
  • antihistamines of the 2nd generation (reducing edema and inflammation);
  • the ambulance team injects epinephrine, prednisolone and hospitalizes the patient in cases of anaphylaxis.

People are recommended to be examined by an allergist to prevent recurrencing disease, to establish a dangerous product and to avoid it in the diet. Continuous medication is not recommended.

Filtrum can be taken immediately after a random allergen eaten: 2 - 3 tablets are ground and drunk down with a large amount of water. This increases drug sorption capacity and lowers risk of allergy symptoms. If signs of the disease have already appeared, then Filtrum is prescribed to be taken for 3 to 5 days. Its dosage depends on the patient`s age and is determined by the doctor.


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