Food allergy (allergic gastroenteritis) is an intestinal disease caused by food-borne antigens. It is characterized by the appearance of both intestinal symptoms (abdominal pain, diarrhea, etc.) and various extraintestinal manifestations, the causes of which are the body’s allergic reactions to antigenic aggression.
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Development mechanism
The immune system must protect the body from external threats. But sometimes she reacts as if they are hostile to substances that do not pose any danger.
In food allergies, the immune system recognizes certain nutrients as foreign and dangerous and initiates a defense process. Certain cells begin to produce a huge amount of protective agents (IgE-type antibodies). They, in turn, cause the release of histamine and other protective substances.
It is histamine that is responsible for many of the body's reactions during allergies, for example, redness of the skin, swelling, narrowing of the trachea, and increased vascular permeability to fluid. This affects the condition of the skin, intestinal mucous membranes, eyes, nasal cavity and bronchi and leads to diarrhea, watery eyes, runny nose, asthma attacks, shortness of breath, rash, redness and itching of the skin.
When an allergen is first introduced into food, the immune system mistakenly recognizes it as dangerous and triggers a protective reaction, forming antibodies. With repeated use, the body either copes with this load or begins to produce even more antibodies, which is the cause of the allergic reaction.
the small intestinal mucosa . Defects in the mucous membrane or its increased permeability allow macromolecules that have antigenic properties (that is, attack the body from the inside) to penetrate into the internal environment of the body.
Painful reactions of the body to food products are not always associated with allergies and immune disorders. Reactions to hot spices, toxins, or preservatives are more common. For example, coffee contains a lot of caffeine, and canned fish contains histamine.
The cause of the body's painful reactions to foods may be enzyme deficiency or, in other words, food intolerance (for example, gluten, fructose, lactose, etc.).
Disruption of the intestinal microflora also leads to reactions similar to allergies.
Sometimes people who have an aversion to a particular type of food attribute this to the fact that they are allergic to that product. In most cases, the allergist does not detect food allergies. However, patients do not trust the research and, having a phobia of a number of foods, doom themselves to a meager and monotonous diet. This often leads to exhaustion. In such cases, you should contact a psychologist or psychiatrist.
What foods cause allergies?
Recently, there has been a widespread increase in allergic reactions, most of which are caused by foods and food additives.
The foods that most often cause allergies include:
- chocolate,
- coffee,
- nuts,
- oranges,
- strawberries,
- crabs,
- eggs,
- milk and other products.
Health effects
Food allergies cause disruption of many intestinal digestive processes. As a result of the action of antigens, the production of enzymes decreases, malabsorption develops, and the release of water and electrolytes into the intestinal lumen increases.
These disorders can also lead to lesions of the intestinal wall, including ulcerative hemorrhagic and granulomatous lesions with the formation of infiltrates in the submucosa.
Signs
The severity of symptoms varies and depends on the state of the immune system. Food allergies are manifested by such symptoms as:
- diarrhea,
- vomit,
- stomach ache,
- intestinal cramps,
- tingling in the mouth and lips,
- swelling of the lips and face,
- dermatitis,
- swelling of the larynx, shortness of breath, asthma,
- urticaria, skin itching,
- and in severe cases, anaphylactic shock.
How to identify food allergies?
The doctor will rule out other diseases that cause similar symptoms, such as celiac disease (gluten intolerance), mild poisoning , or chronic bowel disease (ulcerative colitis and Crohn's disease).
To identify the product that causes an allergy, registration in a food diary of the products consumed and the body's reaction to them is used. Eliminating these foods from the diet leads to the disappearance of symptoms and healing of the intestinal wall.
There is another way to identify allergenic foods. For one week, a simple diet containing
- rice,
- lamb,
- vegetable oil,
- potato,
- apples.
If there are no allergic manifestations, then you should begin to expand your diet and thus identify allergenic foods.
A more accurate diagnosis is based on skin tests with food allergens and blood tests for IgE, the concentrations of which increase with food allergies.
The most modern method is to determine the content of interepithelial lymphocytes (IEL) in the epithelium of the villi of the small intestine. This method allows you to determine whether the body is sensitive to food allergies.
Colonoscopy with biopsy in patients with allergies reveals inflammation of the mucous membrane of the ileum and cecum.
In patients with milk allergy, antibodies to milk proteins are detected in the blood serum.
Complications
In the most severe cases, the allergic reaction can cause asthma and swelling of the larynx, leading to anaphylactic shock.
First aid
- In this case, it is necessary to urgently call an ambulance.
- Give an antihistamine.
- Place the patient on a straight surface, raise his legs slightly above his head, and turn his head to the side.
- Find out what the patient is allergic to and then tell the doctor.
Treatment
The main treatment is to avoid allergy-causing foods. In most cases this is enough.
To eliminate skin and other manifestations of allergies, antihistamines are taken - H1 receptor antagonists (Tavegil, Dimebon, etc.) and H2 receptor antagonists (ranitidine).
There are modern drugs that prevent the release of histamine and show high effectiveness in treating food allergies. These include zaditen, claritin and nalcrom.
If you are allergic to cow's milk proteins, treatment consists of completely avoiding milk and dairy products.
Forecast
In all cases of food allergies, it is enough to identify the allergen and completely eliminate it from the diet. This leads to complete elimination of symptoms.
Milk allergy in children
An allergy to cow's milk proteins was described for the first time by an American pediatrician and is called Heiner's syndrome.
This allergy usually appears in children during the first 4 months of life who are bottle-fed. It can lead to the formation of infiltrates of varying sizes in the lungs. It is possible to develop iron deficiency anemia, recurring diarrhea, and delayed physical development.
Milk allergy develops in 0.2-0.5% of the total number of newborns. Sometimes such allergies occur in both adolescents and adults.
In children, food products most often provoke stomatitis and pharyngitis. However, more detailed data is provided on food allergies in children to milk.
Allergy to milk causes
- diarrhea in 88% of cases,
- vomiting in 44%,
- abdominal pain in 39%,
- atopic dermatitis (skin inflammation) in 33%,
- rhinitis (swelling and nasal congestion) in 31%,
- asthma (difficulty breathing) in 31%,
- urticaria (blisters and itching on the skin) in 13%,
- anaphylactic shock in 13%.
If you are allergic to cow's milk proteins, treatment consists of completely avoiding milk and dairy products.
In infants, it is very important to quickly make a diagnosis and transfer the child to special nutritional formulas that do not contain cow's milk. In this case, the disturbing symptoms subside. But caution must be exercised, since in the future such children continue to suffer from allergies, including to other products (for example, eggs).