Cross Allergy

Cross allergy

Many people who are allergic to pollen can also react to certain foods. This is because the allergens in food are similar to those in pollen. As many as 70% of all birch pollen allergy sufferers experience cross-allergy.

What is cross allergy?

Cross-allergy means that if you are allergic to a substance, for example pollen, you can also react to other substances. The reason is that the allergy-triggering substances (allergens) are similar to each other. It is, for example, very common for birch pollen allergy sufferers to react allergically to nuts, pears and apples. Cross allergy does not worsen the pollen allergy itself.

Cross-allergy does not only happen to pollen allergy sufferers, even those with food allergies can have cross-reactions to other foods, for example.

Cross reactions

People with pollen allergies are often exposed to cross allergies. Some people with pollen allergies only experience reactions to food during the pollen season, while others experience it all year round. What you get cross-reactions to is individual, but the most common cross-reactions can be found in the table here.​​

Birch, hazel, alder, Salix (willow, willow, willow) can cross-react against:​

Apple (raw), pear (raw)​Stone fruit (peach, nectarine, cherry, morel, plum, apricot, almond, mango)​Carrot (raw), potato (raw)​Hazelnut, Brazil nut, walnut​Peanut, celery​Kiwi​

Timotei and other grass species can cross-react against:​​

Legumes (beans, peas, lentils)​Wheat, barley, rye, oats​Melons​​

Burot can cross-react against:

​​​Celery​Leeks, onions, garlic​​​Herbs, herbal spices and herbal medicine (parsley, basil, oregano, coriander etc.)​Paprika​Sunflower seeds​Honey

Symptoms of cross allergy

While pollen allergies mainly cause symptoms in the respiratory tract, food allergies cause symptoms in the mouth and throat in the form of itching and swelling, skin reactions such as eczema and hives and stomach and intestinal symptoms. In rare cases, allergic shock can occur.​

Good advice for cross allergies

• Steer clear of the foods you are allergic to.

• Even if you get a cross-reaction to a food, you don't have to get a cross-reaction to other foods in the table.

• The foods in the table above are often tolerated when they are cooked, peeled, canned or pickled.

• People with a pollen allergy who react to fruit will often tolerate melon, pineapple, grape, banana and citrus fruits and various types of berries (raspberries, currants, blueberries and lingonberries).​

Treatment of cross allergy

Allergy medicines have little place in the preventive treatment of cross-reactions. It is best to avoid the foods you cannot tolerate. People who have experienced very strong allergic reactions should always carry medicine prescribed by a doctor (adrenaline injection) in case they are exposed to what they are allergic to. 

Sources:The Norwegian Asthma and Allergy Association, Norwegian Health Information Technology, Forskning.no and HelseNorge.​