Q&A with Dr. Alice Hoyt on Peaches, Pollens, Peanuts, and Food Allergy
“If a person has a peach allergy, then do they have to worry about having an allergic reaction to pollen that may be made by a bee that visited a peach tree?”
Short answer: highly unlikely.
A person can have immediate onset allergic reactions to peaches in a few different ways. The most common ways are as follows:
- Pollen-Related: The person is allergic to a peach protein that is structurally similar to a pollen protein to which he or she is also allergic .
- NOT Pollen-Related: The person is allergic to a peach protein that is unrelated to a pollen protein.
Pollen Food Allergy Syndrome
Pollen-Related Peach Allergy is a type of pollen food syndrome. Pollen food syndrome, also called pollen food allergy syndrome, is when a person is allergic to a pollen protein but can have allergy symptoms upon ingestion of produce that contain proteins of similar structure to the person’s pollen allergens.
Oral Allergy Syndrome
Oral allergy syndrome, a type of food pollen syndrome, is when a person with pollen allergy experiences uncomfortable mouth symptoms when eating certain fresh produce. As the name suggests, symptoms are limited to the oropharynx (e.g. the mouth area). In the case of peach, some peach proteins are structurally similar to some pollens. This means that if you are allergic to those pollens, then when you bite into a fresh peach, you may have itchy mouth. The symptoms, while uncomfortable, do not progress to anaphylaxis, hence the name oral allergy syndrome. Important note: heat and digestion alter the protein structure, which is why symptoms do not progress beyond the oropharynx and why they don’t occur with cooked produce.
Newer literature suggests that another peach protein, which is structurally similar to cypress pollen, can cause peach-induced anaphylaxis. This too is a food pollen syndrome but different from oral allergy syndrome because symptoms are not limited to the mouth.
But can any of this be related to honey? Rarely. Allergic reactions to honey are quite rare. In fact, many people consume honey hoping it will help with their seasonal allergies (spoiler alert: there’s no evidence that it helps). In most but not all case reports that describe reactions to honey, a bee component or a pollen was the underlying culprit. But again, this is relatively rare. Yet another reason to talk with your allergist if you think this affects you or your kiddo.
Interesting read: check out this oral allergy syndrome case presentation on the AAAAI website.
“I ate peaches earlier this week and thought my mouth kinda tingled but ignored it. The next day, the inside of my mouth was sore, but I didn’t know why. Then yesterday I ate peaches again and had the mouth tingling again and my mouth is sore today. Could this be the peaches?”
Short answer: highly likely.
Fresh peaches can cause the mouth tingling, that being an example of oral allergy syndrome. Peaches and other fruits can also cause a more prolonged soreness and, to some extent, ulcers in the mouth. The underlying pathophysiology of this is less well understood than in other types of food pollen syndromes. While this is rare, it can happen!
“Can you have a peanut allergy that is actually due to a pollen allergy
Short answer: yes.
Just like apples and peaches contain proteins whose structures resemble that of birch pollen, peanuts also contain a protein whose structure resembles that of birch pollen. For example, a teenager may have enjoyed peanut butter her whole life but finds that she now is having mouth itching with peanut butter. The itchiness is the only symptom and only occurs in her mouth, and it resolves a few minutes after eating peanut butter. She also is having significant seasonal allergy symptoms in the spring. The most likely explanation for her new peanut-induced mouth itching is oral allergy syndrome. Specifically, she likely is allergic to a peanut protein that is structurally similar to birch pollen protein. Is she at risk for anaphylaxis? Highly unlikely if this is oral allergy syndrome, but she certainly should see an allergist.
Bonus question: “Can a child with a peanut allergy have an allergic reaction if he or she smells peanut butter?“
Short answer: no.
To trigger an allergic reaction, a person’s immune system must become directly exposed to a triggering amount of an allergen. For example, a person with pollen allergy does not have anaphylaxis when she breathes in pollen in the Springtime; however, she can have anaphylaxis to pollen allergy shots because 1) she is being injected with the pollen (route of exposure) and 2) the amount being injected is an amount known to activate the immune system (threshold dose).
When a kiddo smells peanut butter, she is not inhaling peanut protein; she is smelling the scent of the peanut butter. Now, could smelling peanut butter cause increased heart rate, trouble breathing, nausea, and flushing in someone with a peanut allergy? Yes, but those symptoms, in addition to being symptoms that can occur with an allergic reaction, are also symptoms of an anxiety response. If a person has had an allergic reaction to a food, it is understandable that the food would trigger an anxiety response. Interestingly, many children who are allergic to peanut products spit them out because the taste is so bad to them. (Especially when an allergist is evaluating a young child for possible peanut allergy, this is one subjective symptom that is important to note!)
So much information about peaches and pollens and peanuts and food allergy!
We’ve covered a lot in this infoblog post about peaches, pollens, peanuts, and food allergy! If you want to dive deeper on peach proteins, check out this web page by the manufacturer of food allergy tests. Also, I imagine you must have some questions.
Check out the podcast on peaches, pollens, peanuts, and food allergy!
Additional Show Notes
I have talked about a non-profit…
The non-profit is The Teal Schoolhouse, whose primary program is Code Ana. Code Ana equips schools for medical emergencies like anaphylaxis. Our primary program is the Code Ana School Program, which is a comprehensive approach to school-focused medical preparedness. This program guides schools through the process of creating a medical emergency response plan. This is one of the most important components of a school's food allergy policy!
A medical emergency response plan is important for all kiddos and for adults at any school! Our primary goal is to share the School Program, and Code Ana’s Online Epinephrine Training Program helps support that goal. Through this program, you will educate yourself while you support this important mission! (BTW although Pam and I serve in leadership roles of Code Ana and The Teal Schoolhouse, our time/effort/work is completely voluntary). Does your kiddo’s school have Code Ana?