Cross-allergy and what you need to know about it

"Like attracts like." This expression, as well as possible, characterizes such a phenomenon as cross-allergy. Its essence is the occurrence of an allergic reaction to several pathogens at once. And at first glance, there is nothing in common between them. Judge for yourself, what is the relationship between bananas and latex? But the body of many people reacts to them in exactly the same way.

A similar ailment can manifest itself in any allergy sufferer. And, if you want to avoid such an unpleasant surprise, check out this article. After all, as folk wisdom sounds: “Knowledge is power.”

Crossroads of seven allergens

As you probably know, the cause of an allergy is an abnormal reaction of the body to a foreign protein. In most cases, our body reacts to one or two specific proteins. But the immune system of some "lucky ones" is much less forgiving, and then whole groups of similar compounds are recognized as harmful.

Of the 14 known groups of pathogenic proteins, only 6 can cause cross-allergy. These include:

• Group 2 (beta-glucanase). Found in most tropical fruits, as well as tomatoes and potatoes.
• Group 3 (endochitinase). It is present in many fruits, as well as latex and rubber products.
• Group 4 (chitinase). It is most commonly found in turnips, potatoes, and berries.
• Group 5 (thaumatin-like protein). It is part of many spices, especially black pepper. Also found in apples and cherries.
• Group 10 (ribonuclease). The main birch allergen. However, it is also found in the pollen of most trees in Russian forests. In addition, it can be found in a number of vegetables and fruits.
• Group 14 (lipid transfer protein). It is found in many fruits, as well as in corn, nuts, cereals and olives.

Cross-allergic reactions can be caused by derivatives of the same source. For example, an allergy to cow's milk often coexists with a reaction to beef and veal. And intolerance to fish and seafood can lead to an allergy to chicken products in which "fish" allergens obtained with compound feed are deposited.

It is cross-allergy that is responsible for most self-diagnosis in the style of "I'm allergic to everything." The only exception here is children under 6 years of age, whose allergic reaction is due to a young immune system that has not learned to adequately respond to potential allergens. But by the age of 15, it is possible to draw up a fairly accurate picture of the disease.

Symptoms and diagnosis of the disease

Due to the variety of potential allergens and their routes of penetration, the symptoms of the disease include almost all existing signs. Including:

• Allergic rash accompanied by itching;
• Rhinitis , sneezing, in some cases - swelling of the nasal cavity and lungs;
• allergic conjunctivitis;
• Bronchial asthma;
• Headache;
• Stomach problems, constipation or diarrhea.
• In severe cases, Quincke's edema or anaphylactic shock .

An additional problem with the symptomatology of the disease is the likelihood of atypical symptoms. For example, most birch cross-allergies begin with respiratory symptoms. But sometimes a rash or stomach upset is the first to appear, as with a food allergy. This fact greatly complicates the diagnosis of the disease and the identification of specific allergens. Standard skin and intradermal tests can only narrow the circle of suspects. Therefore, they are usually supplemented by the following tests:

1. Immunoblotting (aka Western blotting). This test, which combines the methods of electrophoresis and enzyme immunoassay, allows you to accurately identify proteins and their associated antibodies;
2. provocative tests . Variety of marker tests. Unlike skin tests, they allow you to identify allergens with greater accuracy. The reverse side of the coin is the increased influence of "provocateurs" on the patient's body.

In addition, there are a number of more specific tests. But all of them can be used only in an outpatient setting.

Treatment methods

Treatment of cross-allergy largely depends on the main (original) allergen and the strength of the response. Sometimes it is enough to simply take antihistamines during an exacerbation and exclude certain foods from the diet. But in severe cases, more serious methods are required:

• Allergen-specific immunotherapy (ASIT). The main caliber of medicine in the fight against allergies. It is based on the principle of "addiction" of the body to allergens, by introducing them in small doses over a certain period. In fact, the duration of treatment is the main problem of this method. Although its efficiency exceeds 80%.
• Autolymphocytotherapy (ALT). A more modern method of treatment based on subcutaneous injections of the patient's own lymphocytes. This method is quite effective in the treatment of cross-allergy forms. In addition, the course of treatment is much shorter than ASIT. The disadvantages are a number of serious contraindications and a limited period of validity (up to 5-7 years).

An important addition to any treatment is a hypoallergenic diet . Moreover, it is formed strictly individually, depending on the results of research on allergens. So, with a cross-allergy to birch, not only citrus and tropical fruits are excluded from the diet, but also carrots and potatoes that are quite harmless at first glance.

A separate word deserves an allergy to medicines. With it, not only drugs containing a potential allergen, but also “pure” drugs with active substances of a similar group can be banned. And that's not to mention food restrictions.

Prevention Tips

Unfortunately, there is no single and effective recipe for preventive measures. Too many potential allergens and their combinations. However, most experts agree that the greatest effect is the prevention of the main type of allergy. Therefore, if you know him, try to block him.

More general advice includes the following:

• Follow the diet prescribed by your doctor. Do not experiment with self-medication. Cross-allergy is not the case;
• Be careful with exotic cuisine and products. Many of these are strong allergens in their own right;
• Give preference to cosmetics marked "Hypoallergenic";
• Do not forget to include information about drugs prohibited for you in the ICE data of your smartphone. This could save your life.

Last, but not least, is timely medical attention. Knowing your illness is very unpleasant, but keep in mind that ignorance does not protect against illness. Be healthy.