Food allergies continue to be a major source of life-threatening reactions in children though while hospital admissions have increased, the fatality rate has actually decreased.
The presence of food allergies has attracted a great deal of attention among both the lay public and healthcare professionals. The most serious form of an allergy reaction, anaphylaxis, is a systemic hypersensitivity response with a rapid onset and which increases the risk of death. While there has been a global increase in hospital admissions due to anaphylaxis, it remains unclear the extent to which this rise is associated with a fatal outcome and whether or not this increase represents a continued upward trend.
Using the Hospital Episodes Statistics Database for England and the Devolved Nations, researchers from the National Heart and Lung Institute, Imperial College, London, extracted all data related to hospital admissions between 1998 and 2018 in which the primary diagnosis was anaphylaxis. The team excluded episodes where a visit to an emergency department did not result in a subsequent admission and included all age groups. They also obtained annual prescribing data for adrenaline autoinjectors.
Overall and between the specified date range, hospital admissions due to allergy increased steadily from a rate of 10 to 28 per 100,000 population. Between 1998 and 2018, there were a total of 255,913 hospital admissions for which 101, 891 (39.8%) were specifically coded as due to anaphylaxis. Limiting the analysis to anaphylaxis admissions, the researchers noted an increase of 179% over the 20-year period from 4.1 to 11.5 per 100,000 population.
Of the 101, 891 anaphylaxis admissions, 30,700 (30.1%) were coded as being due to food and the largest increase was among those aged younger than 15 years, rising from 2.1 to 9.2 admissions per 100,000 population per year, representing an annual increase of 6.6%. Moreover, during this 20 year period, there were 152 deaths which were most likely due to food-induced anaphylaxis; however, the case fatality rate had reduced from 0.70% to 0.30%.
In children under 16 years of age, the most frequent cause of anaphylactic deaths were from nuts (35%), including both peanuts and tree nuts, followed by cow’s milk (26%). Overall, the highest fatality rate occurred in those aged 10–19 years. Another important find was how prescriptions for adrenaline autoinjectors had increased by 336% or 11% per year.
The authors called for more education to highlight the specific risks posed by certain foods such as cow’s milk among those who are deemed allergic.
Conrado AB et al. Food anaphylaxis in the United Kingdom: analysis of national data, 1998-2018. BMJ 2021 https://www.bmj.com/content/372/bmj.n251