Food allergy usually affects infants and children, but some adults also have it. Two types in particular are common: milk allergy and gluten allergy. However, the list of food allergens is much longer. Which foods cause allergies the most, what are the symptoms of a food allergy and how is it treated?

Contents:

  1. Food allergy: causes
  2. Food allergy: the most common food allergens
  3. Food allergy: symptoms
  4. Food allergy: diagnosis
  5. Food allergy: treatment

Food allergy , i.e. allergy to substances contained in food, is a growing problem: data available from WHO (World He alth Organization) shows that food allergy around the world may concern as much as 8 percent. infants and children up to 3 years of age, as well as 1-2 percent. adults.

Although official data on European Union countries say about 7 million people who have a confirmed food allergy, surveys show that even every fifth respondent experiences food allergy symptoms. The first symptoms of food allergy may appear both a few days after birth and a few years later - but it is practically not possible that a food allergy first appears in adulthood.

Food allergy: causes

Food allergy is caused by an abnormal response of the immune system to an allergen found in food. The first contact with the allergen does not cause any symptoms yet, but then the immune system, trying to fight the "enemy", starts to produce substances that - with the next and each subsequent contact with the allergen, will enable a defensive reaction.

It is these substances - depending on the type of allergen, i.e. IgE antibodies or T lymphocytes - stimulate the secretion of histamine and increase pro-inflammatory reactions, in a word: they are responsible for troublesome allergic reactions.

Food allergy: the most common food allergens

What is the most common allergy? Epidemiological studies show that children are most often allergic to cow's milk proteins, egg white and citrus fruits - allergy symptoms may appear in breastfed and artificially fed children, as well as at the stage of expanding the diet.

Expertsemphasize that cow's milk proteins are actually mixtures of many proteins, and some of them are also found in other foods, such as meat (especially beef and veal), as well as in milk products from other animals, such as sheep and goats If consumed, allergy sufferers may also experience milk allergy symptoms.

Adults are most often allergic to fish and seafood, as well as cereals, citrus, soybeans, tomatoes and celery.

The most common food allergens are:

  • wheat flour
  • tomatoes
  • milk
  • peanuts
  • carrot
  • beans
  • celery
  • pea
  • soybeans
  • lentils
  • hazelnuts
  • coconuts
  • peaches
  • almonds
  • baking powder
  • azo dyes, incl. E102, E104, E110, E122, E124, E129
  • egg white
  • fish (especially cod, where the allergen is not only fish meat, but even steam hovering above it during cooking, but also tuna, herring, eel)
  • cereal proteins
  • beef
  • crustaceans
  • mango
  • peaches
  • strawberries

Food allergy: symptoms

Food allergydoes not always have the same symptoms. Often, the same allergen can cause different symptoms in a child and an adult. Both the location of the lesions and their type depend on both the age of the allergic person and the allergen that causes the problem.

  • Symptoms of food allergy in infants and children.The most common symptoms of food allergy in children include: spilling food (in the case of infants) and vomiting, constipation or diarrhea, blood in the stool , gastroesophageal reflux. In infants, a characteristic symptom of food allergy is also intestinal colic - a sign that the digestive system does not tolerate certain ingredients, and the gases present in the intestines excessively stretch their walls, which results in severe pain. A symptom of food allergy may also be fermentative diarrhea with excessive gas and intestinal colic associated with secondary lactose intolerance. Problems with the respiratory system are also common: rhinitis and conjunctivitis, cough, hoarseness, as well as bronchospasm and laryngeal wheezing, which is a characteristic wheezing sound accompanying laryngeal edema and is especially dangerous in infants and young children. There are also skin reactions: most often it is dry, rough skin, erythema and allergic rash. Finally, a symptom of food allergy in children may be a lack of appetite and reluctance to eat meals containing the allergen.anemia, sleep disorders, irritability, attention deficit hyperactivity disorder, and even developmental disorders related to long-term nutrient deficiency.
  • Food allergy symptoms in adultsFood allergy in adults manifests itself with a whole range of symptoms simultaneously. So maybe on the skin both swelling and urticaria, within the respiratory system - rhinitis and asthma, on the part of the central nervous system, among others, migraine, as well as symptoms from the cardiovascular system. The most common symptoms of allergies in adults are: allergic stomatitis, recurrent aphthous stomatitis, oesophageal reflux (often coexisting with asthma), acute allergic gastric mucosa reaction (epigastric pain and vomiting immediately after eating food), chronic allergic reaction stomach and duodenum (chronic dyspeptic symptoms), acute and chronic intestinal disorders, diarrhea, allergic rhinitis, middle ear catarrh, laryngitis, asthma, skin changes (erythema, edema papules, wheals), atopic dermatitis, angioedema, shock anaphylactic. An allergy in adults can also cause other symptoms that are difficult to associate with it: migraines, chronic fatigue syndrome, sleep disturbances, swelling of the hands, feet and joints.
Anaphylactic shock

This is the strongest and most severe symptom of an allergic reaction, which occurs within seconds or minutes of contact with an allergen. In children, it can mainly be caused by nuts, seafood, eggs, citrus, and food additives. Symptoms of shock include itching of the skin and urticaria, as well as coughing, malaise, vomiting, nausea, and the most dangerous respiratory and cardiovascular symptoms: swelling of the respiratory tract and face, drop in blood pressure.

Food allergy: diagnosis

Food allergy diagnosis is not easy. Usually, its first stage is a detailed medical interview, which can help the doctor assess whether there is a genetic predisposition to allergies in the family (because then the risk that the patient could inherit it amounts to several dozen percent). What to do next depends on the severity of the symptoms and the age of the patient.

  • Diagnostics of food allergy in infants.The elimination and provocation test (the so-called open provocation test or - after the inventor's name - the Goldman test) is usually used in the youngest children. from the diet of the suspect food (e.g. milk) for at least two, preferably four weeks. The duration of the test depends on the form of the allergy, e.g. inin case of cutaneous manifestations, elimination should take four weeks. If the symptoms disappear during this time, and after re-introducing the food into the diet, they return and are the same as before, we can talk about success, i.e. identification of the allergen.
  • Diagnostics of food allergy in children.Other tests are carried out in older children: depending on the indications, it may be the determination of specific IgE against allergens in the blood (IgE-dependent mechanisms are involved in approx. 50% of food allergy cases), skin prick and patch tests, or a double-blind placebo-controlled food challenge (DBPCFC), where neither the parent nor the evaluator know what allergen has been identified. used for it. Such tests are most often performed in hospitals due to the possibility of an anaphylactic reaction. Blood allergy tests are only performed on infants over 6 months of age (in younger children, the level of antibodies may still be too low), and spot and patch tests are usually performed on children over 4 years of age.
  • Food allergy diagnosis in adults.Food allergy in adults is difficult to diagnose, there is no single diagnostic method to identify the correct allergen, so you usually need to do several allergy tests. The first type are tests with a dozen or so most allergenic food allergens, regardless of the type of symptoms manifested. Another test is the determination of specific IgE in the blood serum - their detection is an indisputable proof of the existence of an allergy. In case of doubt, the doctor may also order food provocation tests, which consist in administering gradually increasing amounts of the food allergen - until clinical symptoms appear

It is worth knowing that even negative test and test results do not exclude food allergies, because epitopes, i.e. fragments of antigens, contained in protein molecules, which cannot be detected by tests, such as and IgE mechanisms independent.

Food allergy: treatment

The elimination diet, i.e. a diet that completely removes the allergen from the menu, is the only effective therapy in food allergy. During its duration, you cannot eat anything that contains an allergen. Although an elimination diet helps to eliminate bothersome symptoms, when it is poorly balanced, it can result in deficiencies of vitamins and minerals, especially calcium, necessary for proper development.

Therefore, food that causes allergic symptoms, such as milk, must be replacednutritionally equivalent which is well tolerated. The elimination diet is not always the same. The way it is conducted depends on the age, and in the case of children - on the method of feeding. In the case of exclusively breastfed babies, the allergen must be removed from the diet by the nursing mother.

In the case of artificially fed infants who are allergic to cow's milk proteins, the formula is replaced with hydrolysates with a high degree of hydrolysis, and if that is not enough, the toddler uses the so-called elemental diet based on a mixture of amino acids.

Experts recommend that the elimination diet should last at least 6-8 months, but sometimes the elimination diet time is significantly extended. After the time specified by the doctor has elapsed, a provocation test should be performed to assess whether the baby is already tolerating the food. In the case of children, nearly 80 percent. babies with food allergies, such tolerance appears before the age of 5.

However, a lot depends on whether the child is allergic to one allergen, or whether we are dealing with the so-called multi-food allergy, because in this case, tolerance to other allergens does not occur simultaneously.

In some cases, e.g. in the case of a severe allergy to substances present in many food products, the elimination of which is inconvenient or even impossible, desensitization methods are also used, including oral immunotherapy consisting in administering - at a strictly defined time - allergen-containing products. Initially, its amounts are traceable, but they increase during the course of therapy.

Once your food allergy symptoms have subsided, you can eat anything if your doctor agrees. This does not mean that the allergy symptoms will not return: there is always the risk that in some cases, e.g. during an infection, food allergy will reappear. That is why it is worth visiting an allergist once a year, who will order further tests if necessary, and have drugs reducing allergy symptoms in the home medicine cabinet, e.g. antihistamines, medications reducing allergy skin symptoms, and even an ampoule of adrenaline, if the doctor deems it appropriate. necessary.

Category:

Allergies