Food allergies: prevention, diagnosis and treatment

With food allergies, establishing a diagnosis is usually more complicated than, for example, with pollen allergies , because the patient and the doctor must find the trigger in an almost detective-like manner . Thanks to the varied composition of the human diet, it is not at all easy to find out which substance causes an allergic reaction in a given individual . If both skin tests and blood tests for “standard allergens” come back negative, your doctor may ask you to bring in the suspect food for testing at your next visit.

With suspicious foods, a possible allergic reaction can be detected by dripping liquid food (e.g. milk) directly on the forearm , in the case of loose or hard foods, they need to be grated or crumbled and mixed with a drop of water. Then a standard skin test can be performed (see the article Allergy : diagnosis ). This procedure is still used in many allergy clinics, but it can lead to unwanted allergic reactions.

If gluten intolerance is suspected , the doctor may suggest a tissue examination (e.g. a biopsy of the intestinal mucosa ). You will provide very valuable information to your doctor if you keep a detailed daily record of what you have eaten for some time.

Note: Information on the diagnosis and treatment of food allergies and food intolerances cannot replace professional diagnosis and personal advice from a specialist, in this case an allergist. A consultation with a nutritionist may also be appropriate . If you try to “self-diagnose” yourself using information obtained for example from the Internet or through unprofessional tests (eg for IgG instead of IgE ), you can easily end up with malnutrition or improper nutrition.

How are food allergies diagnosed?

The procedure for establishing a diagnosis of food allergies can be broken down roughly as follows:

Anamnestic interview: Part of a comprehensive allergy diagnosis is an interview with a doctor who will thoroughly ask you about the observed problems and possible connections with specific foods. It is also important whether any allergies have already occurred in the family. In this case, there may be an increased susceptibility to allergies. A diet diary is particularly useful and informative for doctors. Through it, the patient documents in detail over a longer period of time what, when and in what quantity he ate, when any problems occurred and how they progressed.

Allergological examination: Different methods are used. The doctor can have a blood sample tested for the level of IgE antibodies , usually skin tests are also performed. More information can be found in the article Allergies: diagnosis .

Diagnostic diet : When a certain allergy is suspected, the most important thing is to avoid contact with the relevant allergen . To confirm his assumption, the doctor may recommend some special dietary measures to the patient, such as an elimination diet or a low-allergen diet (ie, a diet low in allergens), until the symptoms subside. A diagnostic diet followed by a provocation, which is deliberately induced by the consumption of a certain allergen, can only be carried out in specialized centers [1], as severe allergic reactions can also occur during this procedure. Provocation is considered the gold standard in the diagnosis of food allergens, as it provides clear information about whether it is really a clinically relevant allergy, and how large a dose is or is no longer tolerated.

How are food allergies treated?

Treatment consists in limiting or completely eliminating specific allergens received in food. There is no generally valid nutritional recommendation for food allergies or food intolerances.

Tips for prevention

The best preventive measure against food allergies is breastfeeding . According to the World Health Organization ( WHO ), exclusive breastfeeding provides ideal protection for the child during the first six months of life [2]. Breastfeeding or pregnant women are no longer recommended to avoid any food component as a precaution. However, if the infant has already developed an allergy, the nursing mother must avoid consuming the given allergen, as the child could receive it in the breast milk .

If children with existing allergies or with an increased risk of developing allergies are not breastfed, they should receive so-called hypoallergenic nutrition, which contains hydrolyzed milk proteins and essential amino acids . If one parent has an allergy, the child has a 30% risk of developing an allergy. If both parents are allergic, the probability of the child developing an allergy is 60%.

It is not recommended to give babies cow’s milk until they are 6 months old. From the 6th month of life, cow’s milk can be introduced in small amounts (100-200 ml per day, the amount can be gradually increased), through milk cereal porridge. Porridge made from cow’s milk should be consumed by infants only once a day. As a drink, cow’s milk is completely unsuitable in the first year of life.

The introduction of solid food (so-called complementary foods) should be started one spoon at a time between the beginning of the 5th month (17th week) and the end of the 6th month (26th week) of life.

Certain foods, such as fish, eggs or peanuts, were previously considered risky because of the alleged increased risk of developing an allergy. However, the latest scientific studies indicate that when in contact with small amounts of many different foods, the body adapts to them better, and allergies can even be prevented. On the contrary, it has not been proven that the exclusion of so-called allergenic foods from the diet has any preventive effect.