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With or without insurance, you can get a quick, personalized allergy test when it’s convenient for you.Read More
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Everyone has their own unique combination of allergic triggers and not all of them are obvious.Read More
Anaphylaxis, also called anaphylactic shock, is an acute, life-threatening allergic reaction.Read More
Digestive and gastrointestinal issues are closely tied to what you eat.Read More
Does this 4-year-old run the risk of having a severe reaction to peanuts?Read More
Food allergies are the body’s immune system reacting to something that is normally harmless to most people–like milk or eggs.Read More
If you suspect allergies are the cause of your symptoms, it is important to consult with your healthcare professional to get properly diagnosed.Read More
There are options when it comes to testing to identify allergic triggers.Read More
After eating a bowl of fruit and nut cereal, this 8-year-old was covered in large hives—what caused her reaction?Read More
Get answers to some of the most common questions about allergy.Read More
Cross-reactivity occurs when your body's immune system identifies the proteins in one substance (e.g. pollen) and the proteins in another (e.g. fruit & vegetables) as being similar. When you come into contact with either, whether it’s a protein in something that you are truly allergic to or not, your immune system can react in the same way, which can then cause your allergic symptoms.
All that matters, to your immune system, is that the proteins are structurally similar or biologically related and cross-reactivity can occur. The risk of cross-reactivity needs to be assessed by a healthcare professional, and important foods should never be removed from a diet without a confirmed diagnosis.
Cross-reactivity occurs when your body's immune system identifies the proteins in different substances as being structurally similar or biologically related
There’s a high degree of cross-reactivity between cashew and pistachio1 and between walnut, hazelnut and pecan,2 so some healthcare professionals may advise you to avoid all tree nuts even if you only have a confirmed allergy to one.
There’s also a high degree of cross-reactivity between different fish species,3 so healthcare professionals may advise their fish-allergic patients to avoid all fish.
And studies have found that the risk of an allergic reaction to goat's milk or sheep's milk in a person with a cow’s milk allergy is about 90%.4
A common cross-reaction is between birch pollen and stone fruit/kernel fruit such as apples, cherries and pears. If you have a pollen allergy and have experienced an itchy mouth or throat after eating fresh fruit or raw vegetables, you may have Oral Allergy Syndrome (OAS).
OAS, sometimes also called Pollen-Food Allergy Syndrome (PFAS), is usually a temporary and relatively mild condition due to cross reactivity. Some plant foods contain proteins that are similar to the proteins in plant pollens, so for people with OAS, their immune system mistakes the food proteins for the pollen proteins, and they’ll then have a reaction. It is important to remember that not everyone who is allergic to birch pollen reacts allergically to stone and kernel fruits.
In OAS, the immune system mistakes food proteins for pollen proteins, causing an allergic reaction
Not every patient with a pollen allergy will experience a cross reaction with food. Explore below to find the most common culprits of OAS-related reactions.