Increasing Allergy-Related Emergency Department Visits in the United States, 2007 to 2015

Epinephrine treatment of food-induced and other cause anaphylaxis in United States and Canadian Emergency Departments: a systematic review and meta-analysis

INTRODUCTION

Studies from more than 10 years ago showed epinephrine treatment of food-induced anaphylaxis in the emergency department (ED) was unacceptably low. We investigated whether epinephrine treatment of food-induced and other cause anaphylaxis in United States and Canadian EDs has changed over time.

METHODS

Guided by a health sciences librarian, we performed a systematic search in Medline, Embase, and Web of Science on 11 January 2023. We included observational studies that reported epinephrine use to treat anaphylaxis in the ED. We stratified by anaphylaxis etiology (food-, venom-, medication-induced, or any cause). Associations between year and epinephrine use were tested using Spearman correlation and proportional meta-analysis.

RESULTS

Of 2458 records identified in our initial search, 40 met inclusion criteria. Of these, 14 examined food-induced, 4 venom-induced, 0 medication-induced, and 24 any cause anaphylaxis. For epinephrine treatment of food-induced anaphylaxis in the ED, among studies using similar definition of anaphylaxis, meta-analysis showed a pooled value of 20.7% (95% CI 17.8, 23.8) for studies performed >10 years ago and 45.1% (95% CI 38.4, 52.0) from those in the last 10 years. For anaphylaxis of any cause, there was no change over time, with a pooled value of 45.0% (95% CI 39.8, 50.3) over the last 10 years.

DISCUSSION

Epinephrine treatment of food-induced anaphylaxis in the ED has increased over time. There was no clear change for anaphylaxis of any cause. Over the last 10 years, approximately 45% of ED patients with anaphylaxis received epinephrine. A limitation of the evidence is heterogeneity in anaphylaxis definitions.

Impact of Outpatient Antihypertensive Medication Use on Epinephrine Resistance in Anaphylaxis

BACKGROUND

There has been an increase in allergy-related emergency department (ED) visits over the past several years. Underlying cardiovascular disease or respiratory disease and concurrent beta blocker or angiotensin-converting enzyme inhibitor use have been identified as potential risk factors for severe or refractory anaphylactic reactions. Conflicting evidence exists regarding the association between antihypertensive (AH) use and the incidence of refractory anaphylaxis.

OBJECTIVE

The purpose of this study was to determine the incidence of refractory anaphylaxis in patients presenting to the ED while prescribed select AH medications outpatient.

METHODS

This was a retrospective cohort study of all adult and pediatric patients presenting to the ED between February 16, 2021, and August 31, 2021, with a diagnosis of anaphylaxis. The primary objective was to compare the proportion of patients experiencing refractory anaphylaxis that were prescribed versus not prescribed AH medications in the outpatient setting.

RESULTS

A total of 101 patients were treated for anaphylaxis in the ED during the study timeframe with 13 patients in the AH group and 88 patients in the no AH group. There was no difference in the incidence of refractory anaphylaxis between groups (0% vs 9%; p=0.48). Significantly fewer patients in the AH group required any epinephrine doses compared to the no AH group (38% vs 88%; p<0.001).

CONCLUSIONS

Outpatient use of select AH medications was not associated with an increased incidence of refractory anaphylaxis in patients presenting to the ED.

Characteristics of anaphylaxis patients who visited emergency departments in Korea: Results from a national emergency department information system

Background

Anaphylaxis is an allergic disease with fatal respiratory or cardiovascular symptoms that require immediate emergency treatment. We aimed to understand the characteristics and frequency of emergency department (ED) visits of patients with anaphylaxis in Korea.

Methods

Between 2007 and 2013, using data from 147 ED from the National Emergency Department Information System in Korea, we retrospectively evaluated patients with a primary diagnosis of anaphylaxis.

Results

During the study, a total 23,313 patients visited the ED due to anaphylaxis. The number of patients with anaphylaxis who visited the ED increased from 3.0 per 100,000 population in 2007 to 11.6 per 100,000 population in 2013 (P<0.001). Overall, the frequency of anaphylaxis emergency department visits increased by 1.24 times each year (95% CI 1.23–1.25). The risk of visiting ED due to anaphylaxis by population-based age-specific group was highest in the 60–69 years old (OR 2.30, 95% CI 1.96–2.70). Deaths from anaphylaxis increased by 1.35 times per year (95% CI 1.13–1.62). The causes of anaphylaxis were unknown (80.8%; 95% CI 80.35–81.38), drugs (8.9%; 95% CI 8.47–9.24), food (4.1%; 95% CI 3.87–4.39), bees (3.2%; 95% CI 3.02–3.48) and arthropods (2.3%; 95% CI 2.11–2.48). In 2009, drugs were the most common cause of anaphylaxis in November (35.5%), followed by food in May (15.5%) (P<0.001). Between July and September, stings from insects were the most common causes (P<0.001). By age, food was the most common cause in children aged <6 years (7.6%, <12 months; 9.0%, 1–6 years) and drugs in those aged ≥7 years. The 7-year overall mortality rate was 0.104 case per 1,000,000 population; men accounted for 77.8% of the deaths. By region, the number of cases was the highest in metropolitan areas, Gyeonggi and Seoul; however, the number of anaphylaxis cases per 100,000 population was the highest in Jeju and Gangwon.

Conclusion

Based on ICD-10 codes, the number of ED visits due to anaphylaxis is increasing in Korea, and the incidence of anaphylaxis varies by region, season, and age.

Trends in US Emergency Department Visits for Anaphylaxis Among Infants and Toddlers: 2006-2015

BACKGROUND

Anaphylaxis is a potentially life-threatening allergic reaction. The overall prevalence of anaphylaxis appears to be rising in children, but temporal trends among infants and toddlers are not well studied.

OBJECTIVE

To characterize the trends in US emergency department (ED) visits and hospitalizations among infants and toddlers with anaphylaxis from 2006 to 2015.

METHODS

We conducted a study of temporal trends in anaphylaxis among children (age <18 years) and, more specifically, infants and toddlers (age <3 years) presenting to the ED between 2006 and 2015 using a large, nationally representative database. For internal consistency, we defined anaphylaxis using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes and excluded visits with International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes (late 2015). We calculated trends in the number and proportion of ED visits and hospitalizations and used multivariable logistic regression to identify predictors of hospitalization.

RESULTS

Among infants and toddlers, the proportion of ED visits for anaphylaxis per year increased from 20 per 100,000 visits to 50 per 100,000 visits (P_trend < .001). The rate of ED visits for anaphylaxis increased from 15 to 32 ED visits per 100,000 population of infants and toddlers (P_trend < .001). Food was the most commonly identified trigger. The proportion of hospitalization among anaphylaxis-related ED visits decreased from 19% to 6% (P_trend < .001). Among ED patients, those more likely to be hospitalized were male, privately insured, from higher income families, and presenting to urban, metropolitan teaching hospital EDs.

CONCLUSIONS

In a large, nationally representative US database, from 2006 to 2015, ED visits by infants and toddlers with anaphylaxis increased, whereas hospitalization of these patients decreased.