Airborne Anaphylaxis – True or False?

A common question parents and patients have regarding food allergies is this: “Can you have a reaction from smelling a food?”

Here’s what we know:

In order to have anaphylaxis (a severe allergic reaction) to a food, you must come in contact with the protein on a mucous membrane (ie. the mouth, nose, eyes). While this can occur from airborne particles, it is very, very uncommon.

The most common scenario patients ask about is smelling peanut butter. What gives the scent of peanut butter is not a protein. What you are smelling is a chemical called pyrazine and this cannot trigger an allergic reaction. If, however, you were to inhale peanut flour or dust (ie. someone opens a bag of peanuts at a baseball game and the particles get in the air) then you could theoretically have a reaction. These are typically mild reactions.

I have been working in allergy for 4 years and have yet to see any serious allergic reactions to airborne food particles. I have, however, seen many patients who have anxiety provoked reactions from smelling a food. The symptoms of severe anxiety (aka a panic attack) can closely resemble an allergic reaction – increased heart rate, skin flushing, the sensation that one’s throat is closing, and many patients will assume they are having an allergic reaction. These symptoms are real and by no means are these patients “faking”. Living with food allergies is justifiably stressful. If a patient presents with these symptoms to an emergency department, it can be difficult to differentiate an allergic reaction from a panic attack, and often these patients are treated as if they are having anaphylaxis. One test that can help differentiate between a panic attack and allergic reactions is called a SERUM TRYPTASE but must be ordered during the attack. This is a blood test that is elevated for 4 hours after an anaphylactic reaction and should not be elevated during a panic attack.

While airborne allergic reactions are very uncommon, the most common scenario in which they occur is with FRYING FISH OR SHELLFISH. During the process of frying these foods, the protein can be aerosolized and cause a reaction if inhaled. Often this is a runny nose and itchy eyes, and not anaphylaxis. Other airborne food reactions have been reported but again, are very uncommon. If you have specific questions, it is important to see an allergist to have these addressed.

If your child is having recurrent anxiety-driven responses to foods it is important for them to talk to a specialist who deals with anxiety. The stress surrounding food allergies can at times be more detrimental than the allergies themselves. Some level of anxiety is good and protective, but too much can lead to long term consequence and should be addressed early.

I hope this article was helpful and please feel free to add your comments below. Keep in mind I cannot give specific medical advice regarding you or your child’s allergies but will try to respond to general questions. That said, we recently had our fourth baby and time is limited. If I don’t respond, it is likely because I am crying in a corner thinking about my life decisions. J/k. I love my kids. All of them. Even when they deprive me of sleep.

Sincerely,

Dr. Alex Lyttle