Cross allergy: causes, allergist recommendations

Cross allergy: causes, allergist recommendations
  • What is cross allergy
  • How does it manifest itself?
  • How to find the reason
  • List of allergens

An allergy is an abnormal reaction of the immune system to a substance that is not normally dangerous. With an allergy, the immune system perceives it as an aggressor and produces antibodies – this causes symptoms of the disease. But sometimes it happens that symptoms appear in response to other substances that are similar in structure to the allergen. This is how cross-allergy develops.

Cross allergies: causes, allergist recommendations

What is cross allergy

A cross allergy is an allergy in which a reaction is caused by, for example, a piece of fruit eaten. In this case, the allergy will not be to the fruit, but to the antigen that this fruit has in common, for example, with a tree. That is, if you are allergic to birch, then when you eat an apple, you will experience itching, sneezing, and your nose may become stuffy, as if there is a birch tree nearby. At the same time, there is no direct allergy to the apple.

Cross-allergy occurs due to the similar structure of the proteins of the true allergen and another substance. Therefore, if such a substance enters the body, the immune system reacts to it as a true allergen.

The main causes of cross-allergy are not known – it is just as impossible to determine them as it is impossible to determine the main reasons for life on Earth or to identify the reasons for the appearance of fish and birds. Cross allergies are one of the confirmations of the theory of evolution, because all trees and microorganisms, all living things have something in common. Many mammals have common allergens, such as cats and pigs. This means they had common ancestors.

How does cross allergy manifest?

The symptoms of cross-allergy do not differ from the symptoms of classic allergy, but may be less pronounced. The most common:

  • itching, sneezing, runny nose;
  • swelling of the eyelids, lacrimation, redness;
  • skin rashes, peeling, swelling,
  • cough, sore throat, tingling lips.

This allergy is usually milder and is unlikely to cause anaphylactic shock. Most often, this is a food reaction: if you eat an apple if you are allergic to birch, you start sneezing, itching in your mouth, and a stuffy nose. Or alder blooms, this causes the same reaction as to birch, only a little weaker.

Photo: Shutterstock

How to find the cause of cross allergies

A diagnosis of cross-allergy can only be made after consultation with an allergist-immunologist, since similar symptoms make it difficult to determine the true cause of the body’s reaction.

Cross allergies can be caused by different representatives of the same species, for example, birch and alder. Trees are different, but alder pollen carries birch antigens, so a cross occurs – this will cause an allergy to birch too.

During the consultation, the doctor finds out the history of the allergic disease, asks what manifestations are caused by allergens, and, if necessary, can refer you for research. This will help you figure out whether it is a true allergy or a cross allergy, and choose a treatment regimen.

There are systems that allow you to distinguish cross-allergy from direct allergy, so if in doubt you need to go to the doctor, he will prescribe the necessary tests.

List of allergens for cross allergies

In case of cross allergies, some substances can make you feel worse. There are several groups of allergens that can cause similar reactions in other substances:

True allergen → cross allergen

For pollen

Trees → apple, pear, apricot, peach, plum, carrot, kiwi, cherry, banana, potato, nuts, parsley, dill, celery, cumin.

Cereals → grains, legumes, tomatoes, corn, wheat and rye bread, bakery products, rice, millet, pasta, muesli, wheat vodka, beer, kvass, rye, oats, timothy, wheat.

Sagebrush → cumin, chamomile, fennel, anise, sunflower seeds, coriander, capsicum, potatoes, dill.

Sunflower → mayonnaise, vegetable oil, halva, mustard.

Photo: Shutterstock

For products

Cow’s milk → milk from other animals, dairy products, beef, soy.

Chicken eggs → milk from other animals, dairy products, beef, soy, bird feathers, some vaccines.

Stone fruits → pear, prunes, almonds, apple cider vinegar, latex, birch, cherry or peach pollen, wormwood, cereals.

Legumes → peanuts, lentils, grass pollen.

Bananas → kiwi, avocado, melon, latex.

Fish → other types of fish, shellfish, crustaceans.

Walnuts – pollen of trees and grasses.

On medication

Penicillin → cephalosporins, semisynthetic penicillins.

Tetracycline → doxycycline, morphocycline.

Aspirin → other non-steroidal anti-inflammatory drugs (analgin, citramon, askofen).

Novocaine → local anesthetics and sulfonamide drugs.

For other substances

Latex → bananas, kiwi, avocado, chestnut.

Dust mites → seafood.

Molds and yeasts → sauerkraut, cheeses, sour cream, yogurt, kefir, grapes, dried fruits, beer, kvass, dry wines, champagne, penicillin antibiotics, B vitamins, brewer’s yeast.

How to treat cross allergies

If the diagnosis is confirmed, the doctor may recommend a diet limiting certain foods and other ways to reduce contact with allergens: frequent wet cleaning, a protective mask and glasses when outdoors, pollen filters for a vacuum cleaner.

The most commonly used medications are:

  • antihistamines in various forms;
  • topical hormonal medications;
  • vasoconstrictor drops (they must be used carefully so as not to cause dependence).

However, medications can only reduce symptoms. Cross-allergy can be definitively cured only with the help of allergen-specific immunotherapy (ASIT). With this treatment method, the patient receives small doses of the allergen, which increase over time. The body gets used to the substance, and the immune system stops reacting incorrectly to allergens – the symptoms stop and recovery occurs.

The life of a person with allergies is sometimes difficult; the manifestation of allergic reactions can cause a lot of discomfort. When the first symptoms of allergy appear, you should consult an allergist; properly selected therapy will correct this condition and significantly improve your quality of life.