Abstract:
Global passenger demand for air travel has
increased by over 7% annually since 2006, with a strong recovery
following the coronavirus disease 2019 (COVID-19) pandemic.
Prior to COVID-19, individuals with food allergies reported
significant concern and anxiety over the risk of reactions when
travelling by air. However, published data of in-flight medical
events (IMEs) due to allergic reactions are limited.
OBJECTIVE: To undertake a systematic review with meta-
analysis to estimate the incidence of IMEs due to allergic re-
actions on commercial flights.
METHODS: We searched MEDLINE, Embase, PsycINFO, and
TRANSPORT databases and the Cochrane Register of
Controlled Trials for relevant studies reporting IMEs of allergic
etiology, published since 1980. Data were extracted in duplicate
for meta-analysis, and risk of bias assessed. Study registration:
PROSPERO CRD42022384341.
RESULTS: Seventeen studies met the inclusion criteria. At meta-
analysis, a pooled estimate of 2.2% (95% confidence interval
[95% CI] 1.6%e3.1%) of IMEs are coded as being due to
allergic reactions. This may be higher in children (3.1%; 95% CI
1.5%e6.6%). The incidence of allergic IMEs at meta-analysis
was 0.7 events per million passengers (95% CI 0.4e1.1). Reas-
suringly, the rate of allergic IMEs has been stable over the past
30 years, despite increasing passenger numbers and food allergy
prevalence.
CONCLUSIONS: Allergic reactions coded as IMEs during
commercial air travel are uncommon, occurring at an incidence
approximately 10 to 100 times lower than that reported for accidental allergic reactions to food occurring in the comunity. Despite increasing passenger numbers and food al-
lergy prevalence, the rate of allergic IMEs has not changed
over the past 3 decades.
