Hospital admissions for food-induced anaphylaxis is increasing while the number of deaths has fallen, an analysis of UK NHS data has found
A study conducted by scientists from Imperial College London and published in the BMJ has found that deaths from serious allergic reactions (“anaphylaxis”) due to food have declined over the past 20 years. This is despite an increase in hospital admissions for food-induced anaphylaxis over the same time.
The study, funded by the Food Standards Agency and Medical Research Council, analysed 101,891 UK hospital admissions for anaphylaxis between 1998-2018, and found that 30.1% were food- induced.
During the study period from 1998 to 2018, hospital admissions for food-induced anaphylaxis increased by 5.7% per year, or three-fold (from 1.23 to 4.04 admissions per 100,000 population per year). The greatest increase was in children under 15: from 2.1 to 9.2 per 100 000 population per year.
Over the same time, the case fatality rate (number of fatalities compared to hospital admissions) for food-anaphylaxis more than halved, from 0.7% in 1998 to 0.3% in 2018. This may be due to better awareness of food allergy, and how to quickly recognise and treat serious allergic reactions.
Researchers also found that cows’ milk is the commonest single cause of fatal food-induced allergic reactions in school-aged children, accounting for 26% of deaths in children under 16. For adults, nuts were the most common identifiable trigger (23% of deaths). The research team add that cow’s milk is quite protein-rich, meaning a small amount of cow’s milk can result in a significant exposure.
The team at Imperial are now investigating why some people may be more susceptible to severe allergic reactions, and whether factors such as genetics may play a role.
Deaths from food-induced anaphylaxis are rare. The study also assessed food-related anaphylaxis fatalities, recorded since 1992, when data first became available. There had been 187 fatalities since 1992 where the cause of death was likely to be food-induced anaphylaxis.