Allergy to Food Smells

Milk with peanut butter and jelly sandwich

Verywell / Zorica Lakonic

A food allergy is when you have a reaction to a particular food after eating it. However, it is possible to be allergic simply to the smell of a food, too. In some cases, you may be reacting to the fact that you may have inhaled small particles of the food, while in others, the smell may trigger a reaction based on the way your brain processes that odor. This guide delves deep into different scenarios to help you learn more about how the smell of certain foods may affect you.

Allergy to Inhaled Food Particles When You Have a Food Allergy

While it is not common, and it's usually found only in those whose allergies are severe and highly sensitive, an allergic reaction to inhaling small particles (or vapors) of food from the air is possible. In fact, this is an increasingly recognized problem in children. If you've ever been on a plane and you've heard an announcement not to open any packages of peanuts, that's why. 

The most commonly reported type of this reaction is when people with a seafood allergy inhale odors from cooking fish and shellfish. Other foods that can release particles into the air when cooked and may induce allergic reactions include wheat, peanuts, milk, and eggs.

Most people with food allergies don’t—and shouldn’t—worry about food allergens floating in the air that could cause them to have an allergic reaction. Still, it’s probably best for people with severe shellfish allergy to avoid seafood restaurants altogether, rather than to go and order chicken.

Allergy to Inhaled Food When You Don't Have a Food Allergy

Sometimes a food can be eaten with no problem, but issues arise only when small particles of it are inhaled. This is referred to as hypersensitivity to foods by inhalation. This phenomenon can occur with peanuts, cow's milk, fish, shellfish, seeds, soybeans, cereal grains, legumes, hen's egg, coffee, and flour. In fact, there have been several reports of steam allergy to legumes.

Typical symptoms of an airborne allergy to food particles often include runny, watery eyes, coughing, wheezing, and asthma. An anaphylactic reaction is serious and less common but can occur.

It's important to note that kitchens and restaurants aren't the only places where this type of allergic reaction can occur. This can be a problem for some workers who handle food products (such as bakers or coffee bean roasters), or those who work with food additives. These people have an increased risk of developing occupational asthma.

Most exposures occur through the inhalation of dust, steam, vapors, and airborne proteins that are produced in the process of cutting, cleaning, boiling, or drying foods.

Reaction to Food Odor Alone (Without Particle Inhalation)

Some people may have an immediate reaction when they smell a particular food that is not due to the inhalation of food particles, but rather the way that their brains process a particular smell. In this case, the reaction would not be considered a true allergy.

If someone has an allergy—especially a severe food allergy—and smells that particular food being cooked, their brain may immediately register a warning. The subsequent anxiety could, in turn, lead to physical symptoms such as an increased heart rate.

Anxiety can cause the release of stress hormones and adrenaline in a "fight-or-flight response." Sometimes these reactions can be very intense, and they can be mistaken for an allergic reaction.

When in doubt, it is crucial to assume someone may be having an allergic reaction and pursue emergent medical care as needed, rather than to think their reaction is related to anxiety and miss treating life-threatening anaphylaxis.

Cross-Reactions Between Food Allergens and Inhaled Allergens

A different scenario exists in which allergies to inhaled antigens (such as birch pollen) cross-react with antigens in food (such as apple proteins.) This particular reaction, birch-apple, is an example of an oral allergy syndrome.

Oral allergy syndrome has been noted between several airborne allergens and food allergies. Some of these include ragweed and watermelon, grasses and potato, and mugwort and carrots.

Other Causes of Reactions

Beyond eating and inhaling food particles, it's important to note that allergic reactions may also occur in response to skin or mucous membrane contact with even a small amount of an allergen.

It's also worth pointing out that if you're pregnant, your sense of smell is heightened and you may experience aversions to certain foods or food smells (especially during the first trimester). Avoiding particular foods in pregnancy is generally considered to be common and normal, provided that you're still able to eat a variety of other nutritious foods. 

How to Handle Allergic Disease

Unfortunately, allergic disease is increasing. If you suffer from any allergies such as these, make sure to see an allergist. It is important to know what your options are for either avoidance and/or treatment of your symptoms. It's even more important to know whether or not you should have an Epi-Pen available in case of an anaphylactic reaction.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Daniel More, MD

By Daniel More, MD
Daniel More, MD, is a board-certified allergist and clinical immunologist. He is an assistant clinical professor at the University of California, San Francisco School of Medicine and formerly practiced at Central Coast Allergy and Asthma in Salinas, California.