Peanuts on Planes: The Myth of Airborne Allergens
You have probably heard the horror stories about children with extreme peanut allergies having attacks of anaphylaxis on airplanes. A severe reaction is always frightening, but when it occurs up in the air, it can leave a parent, not to mention the child, in a panic. Fortunately, an epinephrine injector can save a child, but it is still a scary situation. The often-blamed culprits are the ubiquitous airlines peanut packets.
Stories have been told of children with severe allergies having attacks as a result of airborne peanut particles. Certainly there are many allergens that can be airborne and cause reactions when inhaled, but the idea that peanut protein can become airborne in a great enough quantity to cause anaphylaxis may just be a myth.
Airborne Peanut Proteins?
The idea that a child can inhale peanut allergens and experience an anaphylactic reaction comes from situations in which the trigger for a reaction can’t easily be found. A child has an allergic reaction yet didn’t eat or touch any peanuts. In these cases, it’s easy to assume that someone nearby eating peanuts caused the allergen to become airborne and that the child inhaled it. However, other possibilities can’t be overlooked. It could be that peanut allergens were present, though not visible, on a surface that the child touched or in a food she ate.
Some experts say that peanut allergens, which are proteins, are simply too heavy to become airborne in any quantity that would be harmful. This assumption doesn’t totally rule out the possibility, though, and researchers have tried to pin down a definitive answer in studies. In one study, for example, children with peanut allergies had peanut butter held about one foot in front of their faces for ten minutes. None experienced a reaction. Although promising, this doesn’t rule out the possibility of inhaling allergens from peanuts in other forms.
Other studies looked at the problem a little less directly. Instead of exposing children to peanut products, other researchers focused on detecting peanut allergens in the air. In one of these studies, researchers looked for Ara h 1, the most common peanut protein that causes allergies, in school environments. Although present on some surfaces, it could not be detected in the air.
In another similar study, researchers again investigated an environment for peanut proteins, but first they asked children participating in the study to consume and use various types of peanut products. They ate peanut butter sandwiches, roasted peanuts and shelled peanuts, and they crushed peanut shells by stepping on them on the school floor. Researchers were again unable to find any airborne allergens.
Food Allergens That Do Go Airborne
Studies may have largely concluded that peanut proteins do not pose a significant risk as airborne allergens, but there are other food allergens that can go airborne and trigger reactions. Even with these, exposure by inhalation is rare. There are two main scenarios in which food particles could be airborne and capable of triggering allergic reactions through inhalation. The first is when that food is being cooked. In heating, foods break down and fluids evaporate. This can lead to proteins that are allergens going into the air. This kind of exposure is most often seen when cooking shellfish or fish, but it can happen with other foods.
The other possibility for creating airborne allergens is when a food is in the form of fine particles, like dust. Wheat flour, for example, is made of small particles that can easily disperse through the air and be inhaled. Anyone with a wheat allergy could have a reaction to inhaling flour particles. Powdered egg and milk could also present this problem.
Many experts agree, based on the research, that dangerous exposure to airborne peanut proteins is largely a myth. In most cases in which airborne peanut particles are blamed for a reaction, there was likely another kind of exposure. This doesn’t mean that people with allergies and parents of children with allergies shouldn’t be careful at all times. The answer to the question of airborne peanuts is not definitive, but if you have a child allergic to peanuts you probably don’t need to worry about the peanut snacks on airplanes. Be careful about exposure from foods and surfaces, always keep an epinephrine injector on hand and take other steps to protect your child.