People with severe peanut allergy often live in constant fear that they will react in the mere presence of peanut. If you're one of these people, you have plenty of reason to fear--a severe reaction can make you miserable and even threaten your life. But just how likely is it that someone eating a peanut butter and jelly sandwich next to you poses a significant threat? The risk is lower than you might think.
As I point out in Food Allergies For Dummies, airborne reactions to peanut protein in peanut butter, candy bars, and even peanut butter crackers is very unlikely. The reason is because the peanut protein, which is responsible for triggering a reaction, is usually contained by some other ingredient in the food, such as chocolate or caramel. You may be able to smell the peanut butter, but the odor is the result of something other than peanut protein.
Caution: Although an airborne reaction from peanut contained in most foods is rare, you may react if the person eating the food is in your face, talking and laughing, and essentially spraying small droplets of peanut at you. You could also react if the person gets peanut on her hands or on the table and it happens to contaminate the food you're eating. It's still a good idea to keep a safe distance from the person and to follow other precautions I outline in the book.Airborne peanut reactions are much more common in situations with high concentrations of peanut dust, such as in restaurants that serve peanuts in shells and encourage patrons to toss the shells on the floor. In a roomful of peanut-cracking, peanut-chomping patrons kicking up peanut dust, the risk of an airborne reaction is very high, indeed, and I strongly advise that anyone with a peanut allergy avoid these situations.