The expert spoke about the peculiarities of cross-allergy

Seasonal allergies can disrupt the rhythm of life, especially if a person does not fully understand what exactly causes his reaction. Symptoms may appear suddenly due to food that was not previously in the diet, or even during a vacation in another country. Often, not only the usual allergens are to blame, but also the so-called cross-allergens. Lyubov Stankevich, PhD, Director of Laboratory Medicine and Manufacturing at the LabQuest and Q Clinic medical companies, explained to Izvestia on May 2 why it is important to know about cross-allergy and how to diagnose it.

"Cross-allergy occurs when the human immune system reacts not only to a specific allergen, but also to other substances with a similar molecular structure. The body perceives these molecules as a "familiar" threat, even if they have a completely different origin. As a result, the reaction can be triggered not by the main allergen, but by its "twin", and often in the most unexpected form," she explained.

According to her, sometimes cross-allergens are quite logical and predictable. For example, if a person is allergic to one berry, there is a high probability that there will be a reaction to other similar berries. So, strawberries can "pull up" an allergy to strawberries, blackberries or lingonberries. The same applies to citrus fruits — if there is a reaction to tangerines, it is highly likely to manifest itself when eating oranges, lemons or limes. As a rule, fish allergies are not limited to just one type — sea and river fish can cause reactions to all seafood.

"But cross-allergens are not always obvious. One of the most striking examples is birch pollen — in spring, during its flowering season, the number of applications increases especially. Many people know that they have a reaction to pollen, but they do not suspect that unpleasant symptoms may occur against this background after eating seemingly harmless products," the expert emphasized.

She clarified that the cross allergens of birch include almonds, apples, pears, cherries, plums, peaches, apricots, kiwis, carrots, potatoes and celery. The immune system recognizes similar molecules in these foods and reacts as if it were pollen itself.

"It is worth mentioning the so-called latex fruit syndrome. People with latex allergies often develop sensitivity to a number of fruits: bananas, avocados, papaya, pineapple, and others. This is due to the fact that the proteins of latex and these fruits have structural similarities that can cause a cross—reaction," said Stankevich.

The expert stressed that even those products that are perceived as an alternative can become a source of problems. For example, if you are allergic to cow's milk, you often have a reaction to goat's milk, despite the widespread myth that it is hypoallergenic. The body perceives the proteins of these two types of milk as similar and reacts accordingly.

In terms of the intensity of manifestations, cross-allergy is no different from the usual one. For some, it may be mild itching or rashes, but in severe cases, life-threatening reactions, including anaphylactic shock, are also possible. That is why it is important to know not only "your" main allergen, but also possible cross-allergens, the specialist noted. This is especially true when planning trips: the national cuisine of another country may contain many unexpected ingredients that a person has simply never tasted at home.

"In order to accurately determine which substances are sensitive, molecular diagnostics is used. One of the most informative methods is the allergy chip. It allows you to determine the body's reaction to more than 300 different allergens in one study, including both basic and cross—allergens," explained Stankevich.

The result of this analysis is a personal allergy passport — a detailed explanation of all identified sensitivities. The information is provided in a convenient form, including graphical symbols, and can be saved to a smartphone.

Earlier, on March 21, an expert doctor at the Hemotest laboratory, allergist Gulnara Memetova, told Izvestia that pollen allergy can occur at any age. However, it not only reduces the quality of life, but can also lead to serious complications such as anaphylaxis and bronchial asthma.