Increased incidence of admissions for anaphylaxis in Spain 1998-2011.

We report on trends in anaphylaxis admissions in the Spanish hospital system during the period 1998-2011. Data on admissions for anaphylaxis were obtained from the Spanish Information System for Hospital Data for the period 1998-2011. Patients were selected using the codes for anaphylaxis in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Poisson regression models were used to estimate incidence rate ratios. We recorded a 1.89-fold increase in admissions for anaphylaxis in Spanish hospitals during the study period, particularly in patients aged 0-14 years (1.65- to 3.22-fold until 2009 and 4.09- to 12.59-fold until 2011) and in food anaphylaxis in all age groups (2.78-fold until 2009 and 8.74-fold until 2011). The incidence of anaphylaxis is perceived as having increased in recent years, especially anaphylaxis caused by food and anaphylaxis affecting the pediatric population.