In conjunction with the Food Allergy and Anaphylaxis Network, researchers at the University of Michigan Medical School have conducted an on-line survey of people who have experienced allergic reactions to peanuts or tree nuts on board a commercial flight. While there are several limitations to such on-line questionnaires, the results highlight that despite greater education and awareness regarding food allergy over the past decade, risks to food allergic individuals travelling on commercial flights remain predominantly unchanged.

Of the 150 respondents who met the research inclusion criteria, 42% claimed to have had multiple in-flight reactions, and more than 30% of respondents had symptoms classified as anaphylaxis aboard the aircraft they were travelling on. While the large majority (76%) of those who suffered a reaction were carrying self-injectable epinephrine, only 10% used it to treat their in-flight reaction.

In nearly 65% of the cases, respondents had notified the airline of their allergy ahead of the flight, and requested special accommodations; these requests were met in less than 40% of cases. Those who carried self-injectable epinephrine were more likely to advise the airline of their allergy prior to boarding.

When asked how they had come in contact with the peanut or tree nut, 16% believed they had ingested it, almost 50% thought it was through inhalation, 30% through skin contact, and nearly 8% were unsure how they had come into contact with the allergen.

Despite their previous reactions, over half (53%) of the respondents said they had not made any changes in their flying behaviour and only 26% said they no longer consume food served on board. Many of them (24%) reported that they now clean their personal seating area and 20% request a peanut or tree nut-free flight. Only 12% reported no longer flying commercially as a result of their allergic reaction.

While the authors concede that in-flight medical events are rare, occurring as 1 event per 753 flights with allergic reactions accounting for 1.7% to 4.6% of all in-flight medical events, they believe there is still a considerable educational gap that remains in keeping those with peanut and tree nut allergies safe while flying.

Reference: Greenhawt et al. 2009. Journal of Allergy and Clinical Immunology. Vol 124(3) pp. 598-9.