The results of present study shown that in Kyiv adult population with allergic rhinitis the sensitization to timothy grass, ragweed, birch, wormwood and Alternaria alternatus mold was predominant and probably play causative role in development of seasonal allergic rhinitis exacerbations with corresponding clinical symptoms and features. Moreover, it was revealed in our investigation, that approximately three quarters of patients with allergic rhinitis also had co-sensitization to food allergens. The sensitization to hazelnut, apple, peanut, celery, soy, fish carp was predominant.
According to some authors, the prevalence of food sensitization among patients with allergic diseases is 37% and it does not differ significantly depending on gender or allergic disease. And the most common allergic disease among adults is allergic rhinitis − 59% . It has also been shown that women are more prone to allergic rhinitis associated with food allergies than men .
In fact, allergic rhinitis is a rare manifestation of food allergies. It may be associated with a primary food allergy; however, it is more commonly associated with secondary food allergies, also known as pollen food syndrome (PFS). Thus, some vegetables and fruits can cause IgE-mediated food allergies (rice, citrus fruits, black lentils and bananas are identified as the main allergens that induce symptoms of allergic rhinitis), and others can cause symptoms of allergic rhinitis due to similarity in structure or homology with pollen. It has been shown that 17% of patients with pollen allergy (ie trees, weeds and grasses) may have a type I allergic reaction to certain vegetarian foods containing fruits and vegetables .
PFS is usually a mild type of food allergy that occurs when the mouth and throat come into contact with raw fruits or vegetables that contain epitopes that are also present in the pollen to which the subject is sensitized. Usually when these products are prepared or processed, they can be consumed without consequences in form of allergic symptoms. Common symptoms of PFS are redness, mild swelling or itching of the lips, tongue, inside of the mouth, soft palate and ears, itching and mild swelling of the throat. Sometimes people may experience symptoms in the esophagus or stomach: abdominal pain, nausea and even vomiting. Symptoms of allergic rhinitis may also include sneezing, runny nose, or, less commonly, allergic conjunctivitis . The most typical example of PFS is the development of oral symptoms when eating apples, hazelnuts, celery, and so on in patients with allergic rhinitis caused by birch pollen due to cross-reactivity. Other examples include hypersensitivity to wormwood, accompanied by symptoms after eating vegetables such as cabbage, cumin, parsley, coriander, anise and carrots, as well as some spices such as anise, pepper, black pepper, onion, garlic, cauliflower and broccoli. Maple pollen, hazelnut, peanut, fruits such as kiwis and peaches, and vegetables such as corn and lettuce, provoke allergic rhinitis symptoms in sensitive people after ingestion. Hypersensitivity to herbs and their classes, as well as their homology with other fruits, has not been studied in detail, but people who are sensitive to herbs are also sensitive to foods such as potatoes, melons, oranges, tomatoes and peanuts . The most common triggers of PFS in adults are apples (21.1%), carrots (15.5%) and peaches (15.5%) . In our present investigation we have compared the rates of sensitization to cross-reactive proteins PR-10 (containing in birch pollen, peanut, soy, apple, celery, carrot and hazelnut) and nsLTP (containing in wormwood, peanut, kiwi, apple, peach, grape, celery, tomato and hazelnut) in patients with only allergic rhinitis and patients with allergic rhinitis and co-sensitization to food allergens. We have revealed that rates of sensitization to PR-10 and nsLTP were significantly higher in patients with both allergic rhinitis and co-sensitization to food allergens comparing to patients with only allergic rhinitis. It should be noticed that these cross-reactive proteins are containing only in several allergen extracts and/or components of the allergen. So, patient may have allergy to birch, but may not have the sensitization to PR-10 protein, because it is included only in Bet v1 component of birch allergen. And this is why some patients may suffer from allergic rhinitis caused by birch and also have its exacerbations after consuming an apple (cross-reactive allergy due to presence of PR-10 in Bet v1 of birch and Mal d1 of apple), but other patients with birch allergy may eat apples without any consequences. So, such cross-reactive proteins may play role as a one of the causes of allergic rhinitis exacerbations and trigger symptoms after consuming some foods in patients with co-sensitization to several food allergens.