Allergy to vegetables: why it occurs and how to prevent?
SPECIFIC FEATURES OF VEGETABLE ALLERGY
Vegetables are an essential part of a healthy diet. But sometimes even they can cause such negative reactions as allergies.
Like any allergy, vegetable hypersensitivity occurs when the immune system identifies the proteins in vegetables as harmful to itself. Upon repeated contact with them, the immune system releases histamine, which then causes the corresponding symptoms to appear.
Allergy to vegetables is possible in two cases: when the body reacts to their proteins on their own, and when, which happens more often, pollen is the cause of the reaction. The second case leads to the development of oral allergy syndrome (OSA).
If a person has a seasonal runny nose during the period of active pollination of certain plants, he is more likely than others to get a reaction to this or that food. Virtually all adults with OSA have a history of allergic rhinitis caused by pollen sensitivity.
However, OSA is considered a relatively mild condition, which in most cases is characterized by the appearance of itching in the mouth or throat after a person has eaten a particular vegetable.
This condition occurs because the pollen proteins are similar to the proteins of some types of vegetables. Therefore, the immune system reacts to both the first and the second.
The most common type of hay fever in Northern and partly Central Europe is an allergy to birch pollen. In Ukraine, about 35% of the population suffers from it.
According to the American Academy of Allergy, Asthma and Immunology, about 50-75% of birch hay fever patients may have some form of OSA.
People who are sensitive to birch pollen may experience allergy symptoms by eating vegetables such as:
· tomato,
· celery,
· carrot,
· dill,
· potato,
· pepper,
cumin,
· lentils,
· beans.
Allergy to the pollen of grasses such as timothy is associated with symptoms of OSA to:
melon,
watermelon,
· tomatoes,
· celery,
· potatoes.
With sensitivity to ragweed pollen, oral allergy syndrome may occur to:
watermelon,
cucumbers,
melon,
zucchini.
An allergy to mugwort may cause sufferers to also react to:
· celery,
parsley
· carrot,
fennel,
· garlic,
· cabbage,
· broccoli,
· sunflower seeds,
cumin,
coriander.
VEGETABLE VEGETABLES – DIFFERENCE
Although most reactions to vegetables are mild, sometimes these allergies can be quite severe.
One of the vegetables, the use of which often leads to severe allergic reactions, including anaphylaxis, is celery.
Allergy to this member of the umbrella family is most often associated with sensitivity to birch pollen.
According to the results of studies, 50% of patients with celery allergy developed local reactions, mainly in the oral cavity. At the same time, the remaining 50% of patients developed systemic reactions. At the same time, in some patients, such systemic reactions occurred even with mechanical contact of the product with the mouth, without the use of celery inside.
In addition, in 48% of patients, allergic reactions began after eating 0.7 grams of this vegetable.
Although many tolerate cooked celery, there are people who may react to this vegetable even after it has been cooked. This is due to the presence of lipid-carrying proteins among celery allergens. They are resistant to digestion and high temperatures.
Celery allergy is one of the most common food reactions caused by pollen in European countries such as Germany, France and Switzerland, where about 40% of patients with food allergies are sensitized to this vegetable. In Ukraine, depending on the region, sensitivity to celery is from 1 to 17% of the population.
Over time, people who are allergic to celery may also begin to react to other members of the celery family: parsley, cumin, dill, coriander.
Sensitivity to carrots can also be associated with a celery allergy. The most common manifestation of allergy to carrots, as well as in the case of most reactions due to sensitivity to birch pollen, is OSA. However, one case of anaphylaxis to raw carrots has been reported.
Another vegetable associated with birch and celery allergies is bell pepper. Simultaneously with OSA, sensitivity to it is also often manifested by symptoms from the gastrointestinal tract. In addition, it contains lipid carrier proteins. This means that it can cause a reaction even after heat treatment.
In general, studies show that the majority of reactions to pepper are rhinoconjunctivitis (50%) and OAS (38%). Urticaria (32%) and allergic asthma (24%) are also observed. Less common are such manifestations as diarrhea (6%), angioedema (3%) and exacerbation of atopic dermatitis (3%).
But lettuce is another vegetable that, although rare, can still be a potential cause of anaphylaxis. Although much more often an allergy to this leafy vegetable is manifested by the same COA.
But potatoes, cabbage, zucchini and pumpkin are considered rarer causes of allergic reactions. As a rule, their manifestations are limited to OSA, although edema, shortness of breath, itching, and so on can also be observed.
Zucchini contains some heat-resistant allergens. And the reaction to potatoes may be related to sensitivity to tomato and latex.
People with tomato allergies may also experience symptoms when eating eggplant. Cross-reactions with latex are also not uncommon.
In addition, tomatoes are a common cause of contact allergies. In general, this vegetable often causes food allergies. From reactions to it, depending on the region, 1.5-20% of the population suffer. For example, if in Northern Europe 1.5% of the population suffers from an allergy to tomatoes, then in Italy – 16%. On average, about 3% of people in the world are allergic to tomatoes.
Almost 40% of patients with hay fever to grass pollen and 2.2 to 4.3% with latex allergy are also sensitive to tomatoes.
Cucumbers can also cause allergies. Such reactions may be associated with ragweed pollen.
People with cucumber allergies are also susceptible to watermelon, pumpkin, and melon, as well as celery and carrots.
SYMPTOMS OF ALLERGY TO VEGETABLES
Often, people with OAS react to certain raw vegetables but may tolerate them once cooked. After all, high temperature causes the destruction of allergenic proteins, which are the cause of cross-reactions.
For some people, symptoms may only appear during seasonal allergies.
Common symptoms of a vegetable allergy are tingling and swelling around the mouth.
The main allergy symptoms after eating vegetables are:
- itching or tingling of the mouth, tongue, or lips;
- swelling of the mouth, tongue and / or larynx (angioedema);
- rarely: vomiting, stomach cramps or diarrhea;
- very rare: anaphylaxis.
Anaphylaxis is a rare consequence of eating vegetables, but it is still possible. Especially, as already noted, after eating celery.
You may also experience:
- intense itching,
- mild wheezing or cough
- nasal congestion.
Symptoms usually appear immediately after eating vegetables. Although in more rare cases, the reaction may occur after an hour or two.
If you suspect that you are allergic to a particular vegetable, you need to contact an allergist who will prescribe the correct treatment and allergy diagnosis . After all, for example, with OSA, a provocative food test, which is often used to diagnose allergies, may be uninformative. Therefore, the nature of sensitivity to vegetables is best determined using multicomponent molecular tests. They will show which food proteins the patient is sensitized to.
As with most food allergies, the main treatment for OAS is to avoid the foods that trigger the allergy. Especially – in the pollen season, if this allergy is associated with hay fever. Allergen-specific immunotherapy may be recommended for people with severe reactions to vegetables and pollen. There is evidence that this technique significantly alleviates the symptoms of both reactions.