Trends in national incidence, lifetime prevalence and adrenaline prescribing for anaphylaxis in England.

BACKGROUND Analysis of primary healthcare datasets offers the possibility to increase understanding of the epidemiology of acute uncommon conditions such as anaphylaxis, but these datasets remain under-exploited. AIM To investigate recent trends in the recorded incidence, lifetime prevalence and prescribing of adrenaline for anaphylaxis in England. METHODS QRESEARCH is one of the world's largest national aggregated health databases containing the records of over nine million patients. We extracted data on all patients with a recorded diagnosis of anaphylaxis and calculated annual age-sex standardized incidence and lifetime period prevalence rates for each year from 2001-2005. We also analysed trends in adrenaline prescribing in those with a recorded diagnosis of anaphylaxis. National population figures were used to estimate numbers of people in England that have experienced anaphylaxis at some point in their lives. RESULTS The age-sex standardized incidence of anaphylaxis was 6.7 per 100,000 person-years in 2001 and increased by 19% to 7.9 in 2005. Lifetime age-sex standardized prevalence of a recorded diagnosis of anaphylaxis was 50.0 per 100,000 in 2001 and increased by 51% to 75.5 in 2005. Prescribing of adrenaline increased by 97% over this period. By the end of 2005 there were an estimated 37,800 people that had experienced anaphylaxis at some point in their lives. CONCLUSIONS Recorded incidence, lifetime prevalence and prescribing of adrenaline for anaphylaxis all showed substantial increases in recent years. An estimated 1 in 1,333 of the English population have at some point in their lives experienced anaphylaxis.