Hospitalizations for Food-Induced Anaphylaxis Between 2016 and 2021: Population-Based Epidemiologic Study.

Background: Food-induced anaphylaxis (FIA) is a major public health problem resulting in serious clinical complications, emergency department visits, hospitalization, and death.

Objective: This study aims to assess the epidemiology and the trends in hospitalizations because of FIA in Spain between 2016 and 2021.

Methods: An observational descriptive study was conducted using data from the Spanish National Hospital discharge database. Information was coded based on the International Classification of Diseases, Tenth Revision. The study population was analyzed by gender and age group and according to food triggers, clinical characteristics, admission to the intensive care unit, severity, and in-hospital mortality. The annual incidence of hospitalizations because of FIA per 100,000 person-years was estimated and analyzed using Poisson regression models. Multivariable logistic regression models were constructed to identify which variables were associated with severe FIA.

Results: A total of 2161 hospital admissions for FIA were recorded in Spain from 2016 to 2021. The overall incidence rate was 0.77 cases per 100,000 person-years. The highest incidence was found in those aged <15 years (3.68), with lower figures among those aged 15 to 59 years (0.25) and ≥60 years (0.29). Poisson regression showed a significant increase in incidence from 2016 to 2021 only among children (3.78 per 100,000 person-years vs 5.02 per 100,000 person-years; P=.04). The most frequent food triggers were "milk and dairy products" (419/2161, 19.39% of cases) and "peanuts or tree nuts and seeds" (409/2161, 18.93%). Of the 2161 patients, 256 (11.85%) were hospitalized because FIA required admission to the intensive care unit, and 11 (0.51%) patients died in the hospital. Among children, the most severe cases of FIA appeared in patients aged 0 to 4 years (40/99, 40%). Among adults, 69.4% (111/160) of cases occurred in those aged 15 to 59 years. Multivariable logistic regression showed the variables associated with severe FIA to be age 15 to 59 years (odds ratio 5.1, 95% CI 3.11-8.36), age ≥60 years (odds ratio 3.87, 95% CI 1.99-7.53), and asthma (odds ratio 1.71,95% CI 1.12-2.58).

Conclusions: In Spain, the incidence of hospitalization because of FIA increased slightly, although the only significant increase (P=.04) was among children. Even if in-hospital mortality remains low and stable, the proportion of severe cases is high and has not improved from 2016 to 2021, with older age and asthma being risk factors for severity. Surveillance must be improved, and preventive strategies must be implemented to reduce the burden of FIA.