Can peanut/tree nut allergic passengers avert an in-flight allergic reaction?

Published Online: March 1, 2013

Flying with a peanut or tree nut allergy can be an anxiety-provoking experience. Prior research, including two articles published in The Journal of Allergy and Clinical Immunology (JACI), has detailed this experience. These studies have noted that few passengers use epinephrine as treatment despite reporting severe reactions, and that passenger requests for accommodations are often denied. New research by an international team, led by Dr. Matthew Greenhawt, MD, MBA, MSc of the University of Michigan Food Allergy Center, sheds some light on in-flight allergic reactions as a global phenomenon, and explores behaviors that may be associated with allergic passengers who fly safely, without suffering a reaction. Past research has focused exclusively on US travelers, as well as on only those patients who have reported a reaction.  

In a recent manuscript published in The Journal of Allergy and Clinical Immunology: In Practice, Greenhawt et al. describes an open, internet survey-based study of air travelers with peanut and tree nut allergies, conducted through the websites of the International Food Allergy & Anaphylaxis Alliance across 11 countries. Respondents were asked to provide details about their pre-flight preparation, including passenger and air carrier nationality, specific accommodation requests and whether these requests were granted or denied, medication carriage, in-flight eating habits, and, for those reporting a reaction, the details about the trigger, symptoms, and treatment of the reaction. Both individuals reporting a reaction as well as those who did not were included in the study. Regression analysis was used to determine any association between specific pre-flight/in-flight behaviors, requests for accommodation, nationality, and the odds of reporting an allergic reaction. Regression analysis was also used to determine the association of these with and other variables and the odds of a passenger using epinephrine to treat a reported reaction.

The team found some very intriguing results. They noted 349 reactions reported among 3,273 respondents from 10 countries. Only 13.3% of passengers received epinephrine as treatment. Flight crews were notified regarding 50.1% of reactions. Approximately 69% of all respondents reported making a pre-flight accommodation request, though significantly fewer individuals reporting a reaction made such a request, compared to those who did not report a reaction. The adjusted odds of epinephrine use to treat a reported reaction were increased with gastrointestinal or cardiovascular symptoms, or among individuals notifying the crew of an ongoing reaction. Interestingly, nationality was not a significant factor influencing the use of epinephrine as treatment. Most importantly, Greenhawt et al. focused on behaviors associated with safe flying. They found 8 reported behaviors with favorable associations. Passengers (1) requesting any accommodation, (2) requesting a peanut/tree nut-free meal, (3) wiping their tray table with a commercial wipe, (4) avoiding use of airline pillows or (5) blankets, (6) requesting a peanut/tree nut-free buffer zone, (7) requesting other passengers not consume peanut/tree nut-containing products, or (8) not consuming airline-provided food had significantly lower adjusted odds of reporting a reaction. Significant differences in the utilization of these behaviors based on nationality were noted, however.

This is the first study to show that in-flight peanut and tree nut allergy is an international problem, to determine factors associated with the decision to use epinephrine to treat a reaction, as well as to show that certain pre-flight/in-flight behaviors are associated with a lower likelihood of suffering an in-flight allergic reaction. Passenger nationality does affect what pre-flight notifications or in-flight preparations at-risk passengers will make, but does not affect the odds of using epinephrine to treat a reaction. Unfortunately, it was once again noted that epinephrine was sparsely utilized to treat in-flight reactions, though Greenhawt et al. provide some insight into what factors may be associated with its use, which can help with educational efforts.  

Flying with a peanut/tree nut allergy is equal parts frustrating and frightening for allergic passengers. These 8 passenger-initiated risk-mitigating behaviors may be of assistance to clinicians wishing to advise concerned patients planning to fly commercially. Given that Canada is the only country with any formal policy in place, restricted to just a 3-row buffer zone with advance notification only on Air Canada flights, these behaviors are simple, practical measures which may offer some protection until formal policy can be implemented. Future study is necessary to further validate the effectiveness of these passenger-initiated risk-mitigating behaviors.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

Close-up of pine tree branches in Winter Close-up of pine tree branches in Winter