Rationale: Small case series suggest that teenagers and young adults may be at higher risk of fatal food-induced anaphylaxis than other age groups, but this has not been confirmed in large population-based datasets.
Methods: We extracted data from national databases for hospital admissions and fatalities due to anaphylaxis in England and Wales for the period 1992-2011, and cross-checked fatalities against a prospective fatal anaphylaxis registry. We examined time trends and age distribution for fatal reactions caused by food, drugs and insect stings, and compared these to equivalent data previously published from Australia.
Results: Hospital admissions due to anaphylaxis admissions increased steadily over the time periods studied in both the UK and Australia, but fatality rates have remained stable at around 0.04 (UK) and 0.05 (Aus) cases per 100,000 population per annum. Fatalities and admissions were most common in older people for drug- and insect sting-induced anaphylaxis. For food-triggered reactions, fatalities were most common in teenagers and young adults, in both countries. These findings are not explained by age-related differences in the prevalence of food anaphylaxis requiring hospitalisation.
Conclusions: In the UK and Australia, hospitalisations for anaphylaxis have increased, but fatal anaphylaxis has not. Possible explanations include increasing recognition of anaphylaxis, improved management and a real increase in the prevalence of food allergy. Of note, the age-distribution of fatal cases varies significantly according to the nature of the eliciting agent, and raises important questions about the differences in the pathogenesis of anaphylaxis between different triggers.