A tomato allergy is characterized by an overreaction of the immune system to the consumption of tomatoes.
However, affected individuals are more likely not allergic to the tomato itself. Rather, the tomato contains the substance histamine, which plays an important role in the immune system in allergies.
Affected persons usually have a histamine intolerance, which acts like a tomato allergy. The histamine causes the release of various immune substances that cause the typical symptoms such as itching, burning on the tongue, nausea, vomiting and diarrhea.
The symptoms of tomato allergy always occur at a certain interval after eating tomatoes. Symptoms include gastrointestinal symptoms such as nausea, vomiting, abdominal pain and diarrhea.
For more severe allergies, the mouth and throat area may also be affected. There is a burning or itching on the mucous membranes and on the tongue. Also redness and swelling are possible. An extended allergic reaction also includes a rash that is usually near the area of contact with the tomato (ie, the face, especially around the mouth).
When eating tomatoes, the tongue comes into direct contact with the allergen. Therefore, the symptoms can be particularly severe there.
This includes a burning and itching on the tongue. Even redness to small bubbles can be a sign of tomato allergy. In severe cases, the tongue swells due to contact with tomatoes, which can lead to respiratory problems. If the swelling is so severe that the throat is affected, it can even lead to life-threatening shortness of breath.
When it comes to contact with tomatoes, the immune system reacts more and more to harmless substances by allergic persons. The body interprets the tomato or its ingredients as a dangerous substance and therefore tries to combat it.
This process leads to an increased release of immune cells and signaling substances, which put the body on alert. These secreted substances are distributed as quickly as possible in the body, so that an optimal defense against the dangerous tomato can take place. These well-distributed substances irritate the nerve endings and trigger an itching.
Diarrhea, in addition to nausea, vomiting, flatulence and abdominal pain, is one of the symptoms of the gastrointestinal tract, which is particularly common in allergies to food.
In the intestine, the food is usually crushed into its individual components and then absorbed into the blood. Due to the high degree of comminution, the body has in many places contact with the ingredients of the tomato and inevitably also with the histamine, to which the immune system reacts more intensively.
The goal of this allergic reaction is, among other things, the rapid removal of the tomato from the intestine. Such a removal is possible very quickly with the help of diarrhea, which is why the body uses diarrhea as an effective defense strategy.
The eyes are typically unaffected by a tomato allergy.
They are more likely to respond to cross-allergies, such as when a person is allergic to birch pollen. Due to the chemical similarity of the substances, there is also an allergic reaction to the tomato. This can manifest itself through a constantly running nose, which in turn has an influence on the eyes.
Nevertheless, the typical allergic symptoms such as burning or itching of the eyes, in addition redness and swelling are rather rare in tomato allergies.
The most effective therapy for allergies is the complete abandonment of the food that triggers the allergy. So if you suffer from a tomato allergy, you can live without tomatoes for the rest of your life and thus avoid any allergic symptoms caused by tomatoes.
Important for this is a correct and unambiguous diagnosis of the allergen, so that this food waiver can be carried out correctly. Since the allergic reaction to the tomato takes place mainly due to the substance histamine, so-called antihistamines are commonly used drugs. These tablets block the extra secretion of histamine in the body, which can alleviate the symptoms. However, the antihistamines can not cure the disease because they can not fight the root cause.
As with any other allergy, every allergic person should be prepared for an emergency, ie a life-threatening allergic shock. This is the emergency kit, which consists of an Epi-Pen containing the active ingredient epinephrine (also called adrenaline), and possibly additional cortisone-containing sprays. An allergic shock leads to severe respiratory distress and a circulatory collapse within a few seconds to minutes. The epinephrine from the epi-pen can usually still be applied by the affected person himself and counteracts the allergic shock within a very short time.
The exact cause of the tomato allergy is not yet clear.
However, it is certain that there is a genetic component. Anyone with food allergies has a greater risk of being allergic to food.
There is also the theory that a particularly clean environment leads to increased susceptibility to allergies. In a clean environment, the body does not come into contact with many substances. So he can not get used to the substances and estimates them at a later contact as dangerous. This leads to the strong immune reaction to actually harmless foods like the tomato.
Cross-allergies arise due to the chemical similarity of the allergens (allergy-causing substances) of various foods. So the immune system not only recognizes the actual food that someone is allergic to. Other foods or pollen are also interpreted as dangerous and therefore attacked by the body. Cross allergies with tomatoes makes the birch tree especially. Other foods can cause cross-allergies, including cherry, pear, apple, hazelnut and almond. Rarer are banana, orange and mango.
The allergic reaction to certain foods is due to an overreaction of the immune system to the foreign substance. Normally, there is a first contact of the body with the substance, whereupon immune cells are formed, which recognize certain surface proteins (proteins on the surface of the substance). Upon second contact with the affected food, the immune system recognizes these surface proteins because of the immune cells that have already been formed. This mechanism is actually intended as a defense against dangerous substances.
In an allergic reaction, however, the body reacts to an actually harmless substance with an excessive immune response. The key stimulus for the immune system is the recognition of the above-mentioned surface proteins. These are configured in a fresh tomato as the immune system has detected it on first contact. By heating the tomatoes, these surface proteins are also heated. The proteins denature, the superficial proteins are thus destroyed by heating, or their shape changes. Thus, the immune cells of the body can no longer recognize the tomato proteins and an immune reaction against the heated tomato remains.
The diagnosis of tomato allergy is based on the history. The doctor asks the symptoms of the person concerned. Particularly important is the temporal relationship between the consumption of tomato and the onset of symptoms such as itching, diarrhea and nausea. If these symptoms are unequivocally attributable to tomato consumption, further diagnostics can be dispensed with.
However, to perform a safe diagnosis, the so-called prick test is used. For this, the affected person is injected with a minimal amount of the tomato allergens under the skin. Subsequently, in tomato allergy, a skin reaction in the form of redness, swelling and itching at the site of injection is expected.
The tomato allergy is basically a non-curable disease. Since the exact causes and disease mechanisms are not yet fully understood, there is still no healing therapy option. The tomato allergy therefore lasts for a lifetime.
Nevertheless, the duration of the individual allergic attacks strongly depends on how strictly the person concerned abstains from abstaining from tomatoes. Also, the severity of the reaction varies greatly from person to person.
An allergic reaction can develop at the earliest on the second contact with the affected allergen. First, it is necessary to contact the immune system with the allergen. This antibody is formed against the substance. These alarm the immune system during the second contact with the allergen and attack the substance.
The further course depends heavily on the frequency of tomato consumption. Those who refuse knit tomatoes will probably never feel any symptoms again. Those who come into contact with tomatoes more often and consume them, can usually perceive an intensification of the allergy.