International study of risk-mitigating factors and in-flight allergic reactions to peanut and tree nut

Three studies have analyzed in-flight peanut/tree nut reactions, although the studies were conducted exclusively among Americans.

We studied the international in-flight experience and determined the efficacy of certain risk-mitigation strategies.

A 47-question on-line survey was distributed through the websites and social media outlets of the member organizations of the Food Allergy & Anaphylaxis Alliance. Both persons reporting an in-flight reaction and nonreactors were surveyed to assess details of air travel preparation and any reported reaction. Data were analyzed to determine the association among flying behaviors, reported reactions, and nationality.

We found that 349 reactions were reported among 3273 respondents from 11 countries; 13.3% received epinephrine as treatment. Flight crews were notified about 50.1% of reactions. Sixty-nine percent of all respondents reported making a preflight accommodation request, although just 55% of reactors did so compared with 71.6% of nonreactors (P < .001). Adjusted odds of epinephrine use were increased with reported gastrointestinal or cardiovascular symptoms or with notifying the crew. Passengers who requested any accommodation, requested a peanut/tree nut-free meal, wiped their tray table, avoided airline pillows or blankets, requested a buffer zone, requested other passengers not consume peanut/tree nut-containing products, or reported not consuming airline-provided food had significantly lower adjusted odds of reporting a reaction.

In-flight peanut and tree nut reactions occur internationally. Epinephrine was sparsely used to treat reactions. We identified 8 risk-mitigating behaviors associated with lower odds of a reported reaction. Future study is necessary to further validate the effectiveness of these passenger-initiated risk-mitigating behaviors.