The concept of cross-allergy

The consumption of various foods can pose challenges for many allergy sufferers, as unpleasant symptoms may arise even when the allergen concentration in the environment is not elevated. In many cases, the symptoms are a consequence of cross-allergy, which is based on the reaction of substances with similar chemical structures. This phenomenon complicates the lives of many allergic individuals, as not only pollen allergies but also foods can cause problems.

The essence of cross-allergy is that certain allergens, such as pollens, resemble other substances, making it difficult for the body to distinguish between them. As a result, for already sensitive individuals, allergic reactions can intensify, and even new complaints may arise. The occurrence of cross-allergies is relatively low, but it is much more common among pollen allergy sufferers, as cross-reactions can occur in as many as 30% of birch pollen allergy sufferers.

This article provides a detailed overview of the concept of cross-allergy, its symptoms, the most common cross-allergic foods, as well as prevention and treatment options.

The Concept and Development of Cross-Allergy

Cross-allergy is a phenomenon in which the body’s reaction to one allergen also triggers reactions to other chemically similar substances. This phenomenon mainly occurs in allergic individuals who are already more sensitive to allergens. The underlying cause of allergic reactions is the similarity in the chemical structures of different substances. The body cannot distinguish between the two substances, leading to intensified reactions.

The most common cases of cross-allergy include cross-reactions between pollen and certain fruits and vegetables. For example, individuals allergic to birch pollen often experience allergic symptoms when consuming apples, apricots, or even hazelnuts. The possibility of cross-allergy is not limited to pollen allergy sufferers but can also be observed in other types of allergies, such as food allergies.

Although cross-allergy is relatively rare, it can occur in 5-10% of allergic patients. However, the rate of cross-reactions among birch pollen allergy sufferers is much higher, and symptoms often become more pronounced during allergy season. Therefore, cross-allergy is a complex phenomenon that requires conscious attention from those affected, as complaints often arise unexpectedly.

Symptoms and Effects of Cross-Allergy

The symptoms of cross-allergy vary widely, with oral allergy syndrome (OAS) being the most characteristic form. In OAS, unpleasant sensations occur in the oral cavity, such as itching, throat irritation, lip and tongue swelling. These symptoms typically arise shortly after consuming cross-allergic foods and usually resolve on their own within a few hours.

Other symptoms of cross-allergy may include sneezing, runny nose, tearing, and itchy eyes. These complaints are the result of inflammatory reactions in the respiratory system and are closely related to pollen concentration. During allergy season, symptoms may intensify, and patients often report stronger complaints after consuming various foods.

The occurrence of cross-allergies is not always predictable, and while many allergic individuals may experience cross-reactions, many may remain symptom-free. The severity of allergic reactions varies, and different foods, as well as their preparation methods (such as cooking), can influence the appearance of reactions.

Cross-Allergies and the Most Common Foods

Cross-allergy can occur with various types of allergies, including pollen allergies, food allergies, as well as dust mite or latex allergies. Numerous examples of cross-allergies exist, including the following:

– **Ragweed**: Watermelon, cantaloupe, tomato, cucumber.

– **Black wormwood**: Cumin, chili pepper, paprika, potato, coriander.

– **Birch**: Hazelnut, walnut, apple, pear, plum, peach.

– **Alder**: Apple, pear, cherry, almond.

– **Grasses**: Tomato, wheat, soybean.

– **Peanut**: Walnut.

– **Nuts**: Wheat, poppy, hazelnut.

– **Latex**: Chestnut, banana, citrus fruits.

It is important to note that not every allergic individual reacts to the foods mentioned above. Many are sensitive only to certain foods or specific varieties. Cross-allergies typically occur after consuming raw foods, as cooking often changes the chemical composition, reducing the likelihood of reactions.

Actions and Prevention in Case of Cross-Allergy

One of the most important steps in managing cross-allergy is avoiding the consumption of the offending foods. For those who know what they are allergic to, it is crucial to be aware of the list of foods that can cause cross-allergy. If they experience symptoms of oral allergy syndrome, it is advisable to avoid the specific food. However, in a symptom-free state, avoiding allergens is not necessary.

During prevention, particular attention should be paid to the consumption of raw foods, as cooking can often reduce the likelihood of cross-reactions. Taking antihistamines is also recommended to alleviate allergic symptoms, especially during pollen season. These medications can help mitigate cross-allergic complaints as well.

In rare cases, when cross-allergy leads to severe reactions, such as anaphylaxis, immediate medical attention is essential. In such cases, the use of a life-saving adrenaline auto-injector may also be necessary.

To avoid cross-allergic complaints, it is advisable to consult with an allergist who can help develop appropriate treatment and prevention strategies, especially before the onset of pollen season.