Comparison of the incidence, etiology, and management of anaphylaxis over time

Population-based incidence of all-cause anaphylaxis and its development over time: a systematic review and meta-analysis

Introduction

It is extremely difficult to compare studies investigating the frequency of anaphylaxis making it challenging to satisfactorily assess the worldwide incidence rate. Using a systematic review and meta-analysis, this publication aims to determine the current incidence of all-cause anaphylaxis worldwide. Additionally, we investigated whether the incidence of anaphylaxis has changed over time and which factors influence the rates determined by individual studies.

Methods

A literature search was performed in four databases. All articles that reported relevant information on population-based incidence rates of all-cause anaphylaxis were included. The protocol was published on INPLASY, the International Platform of Registered Systematic Review and Meta-analysis Protocols.

Results

The database query and screening process resulted in 46 eligible articles on anaphylaxis. The current incidence worldwide was found to be approximately 46 cases per 100,000 population per year (95% CI 21-103). Evaluating confounding factors showed that studies using allergy clinics and hospitalizations as data source result in comparably low rates. Moreover, children are less prone to develop anaphylaxis compared to the general population. Using a random effects Poisson model we calculated a yearly increase of anaphylaxis incidence by 7.4% (95% CI 7.3-7.6, p < 0.05).

Discussion

This seems to be the first approach to analyze every reported all-cause anaphylaxis incidence rate until 2017 for an at most accurate determination of its epidemiology. Based on these results, future research could investigate the underlying causes for the rising incidence in order find ways to decrease the condition's frequency.

Systematic Review Registration

inplasy.com, identifier [INPLASY202330047].

U.S. Population-Based background incidence rates of medical conditions for use in safety assessment of COVID-19 vaccines

The Coronavirus Disease 2019 (COVID-19) pandemic has had a devastating impact on global health, and has resulted in an unprecedented, international collaborative effort to develop vaccines to control the outbreak, protect human lives, and avoid further social and economic disruption. Mass vaccination campaigns are underway in multiple countries and are expected worldwide once more vaccine becomes available. Some early candidate vaccines use novel platforms, such as mRNA encapsulated in lipid nanoparticles, and relatively new platforms, such as replication-deficient viral vectors. While these new vaccine platforms hold promise, limited safety data in humans are available. Serious health outcomes linked to vaccinations are rare, and some outcomes may occur incidentally in the vaccinated population. Knowledge of background incidence rates of these medical conditions is a critical component of vaccine safety monitoring to aid in the assessment of adverse events temporally associated with vaccination and to put these events into context with what would be expected due to chance alone. A list of 22 potential adverse events of special interest (AESI), including neurologic, autoimmune, and cardiovascular disorders, was compiled by subject matter experts at the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention. The most recently available U.S. background rates for these medical conditions, overall and by age, sex, and race/ethnicity (when available), were sourced from reported statistics (data published by medical panels/ associations or federal government reports), and literature reviews in PubMed. This review provides estimates of background incidence rates for medical conditions that may be monitored or studied as AESI during safety surveillance and research for COVID-19 vaccines and other new vaccines.

Changes in Emergency Department Concordance with Guidelines for the Management of Food-Induced Anaphylaxis: 1999-2001 versus 2013-2015

BACKGROUND

Awareness about food allergy and food-induced anaphylaxis (FIA) has increased dramatically over the past decade. It remains unclear, however, whether concordance with guidelines for FIA management has improved over time.

OBJECTIVE

Our objective was to describe changes in emergency department (ED) concordance with guidelines for FIA management.

METHODS

We analyzed data from 2 multicenter retrospective studies of patients with food-related acute allergic reactions seen in 1 of 17 EDs during 2 time periods: 1999 to 2001 and 2013 to 2015. Visits were identified similarly across years-for example, using International Classification of Diseases, Ninth Revision, Clinical Modification codes 693.1, 995.60, 995.61-995.69, 995.0, and 995.3. Anaphylaxis was defined as an acute allergic reaction with involvement of 2+ organ systems or hypotension. We compared concordance between time periods for 4 guideline recommendations: (1) treatment with epinephrine, (2) discharge prescription for an epinephrine autoinjector (EAI), (3) referral to an allergist/immunologist, and (4) instructions to avoid offending allergen.

RESULTS

We compared 290 patients with FIA during 1999 to 2001 and 459 during 2013 to 2015. Any treatment with epinephrine (pre-ED or in the ED) for patients with FIA increased over time (38% vs 56%; P < .001). Prescriptions for EAI at discharge (24% vs 54%; P < .001) and documentation for referral to an allergist/immunologist (14% vs 24%; P = .001) approximately doubled, whereas instructions to avoid the offending allergen did not change significantly (37% vs 43%; P = .08). Receipt of 3+ guideline recommendations remained low but almost quadrupled over the study interval (6% vs 23%; P < .001).

CONCLUSIONS

Over the nearly 15-year study interval, we observed clinically and statistically significant increases in ED concordance with epinephrine-related guidelines for FIA. Management gaps remain and interventions to standardize care still appear warranted.

Changes in emergency department concordance with guidelines for the management of stinging insect-induced anaphylaxis: 1999-2001 vs 2013-2015

BACKGROUND

Changes in emergency department (ED) concordance with guidelines for the management of stinging insect-induced anaphylaxis (SIIA) are not known.

OBJECTIVE

To describe temporal changes in ED concordance with guidelines for the management of SIIAs.

METHODS

We analyzed data from 2 multicenter retrospective studies of patients with stinging insect-related acute allergic reactions seen in 1 of 14 North American EDs during 2 periods: 1999 through 2001 and 2013 through 2015. Visits were identified similarly across studies (eg, using International Classification of Diseases, Ninth Revision, Clinical Modification codes 989.5, 995.0, and 995.3). Anaphylaxis was defined as an acute allergic reaction with involvement of at least 2 organ systems or hypotension. We compared concordance between periods with 4 guideline recommendations: (1) treatment with epinephrine, (2) discharge prescription for epinephrine auto-injector, (3) referral to an allergist/immunologist, and (4) instructions to avoid the offending allergen.

RESULTS

We compared 182 patients with SIIA during 1999 to 2001 with 204 during 2013 to 2015. Any treatment with epinephrine (before arrival to the ED or in the ED) increased over time (30% vs 49%; P < .001). Prescriptions for epinephrine auto-injector at discharge increased significantly (34% vs 57%; P < .001), whereas documentation of referral to an allergist/immunologist decreased (28% vs 12%; P = .002), and instructions to avoid the offending allergen did not change (23% vs 24%; P = .94). Receipt of at least 3 guideline recommendations increased over time; however, the comparison was not statistically significant (10% vs 16%; P = .15).

CONCLUSION

During the nearly 15-year study interval, we observed increased ED concordance with epinephrine-related guideline recommendations for the management of SIIA. Reasons for the decrease in allergy/immunology referrals merit further study.

Anaphylaxis to foods in a population of adolescents: incidence, characteristics and associated risks

BACKGROUND

Information about severe reactions to foods in adolescence is limited.

OBJECTIVE

To describe reactions to foods, including anaphylaxis, with regard to incidence, characteristics and associated risks, among 16-year-olds (adolescents) in a large, population-based birth cohort.

METHODS

Parent-reported questionnaire data from ages 2-3 months, and 1, 2 and 16 years were used (N = 3153). Anaphylaxis at age 16 years was defined per NIAID/FAAN criteria. Immunoglobulin E (IgE) antibodies to 14 common food and inhalant allergens were analysed at ages 4 (n = 2283) and 16 years (n = 2510). Among adolescents with food-related symptoms (FRS) and for whom blood was available (n = 221), 25 additional food allergen extracts or allergen components were analysed. Associations between reactions to foods, and sensitization and allergic multimorbidity were investigated.

RESULTS

In the 12 months prior to the 16-year assessment, 8.5% of adolescents had FRS. This included 0.8% (n = 24) adolescents who were classified as having anaphylaxis, yielding an incidence rate of 761/100 000 person-years. One-third of adolescents accessed health care during anaphylaxis. Allergic multimorbidity in infancy, as well as sensitization to foods and airborne allergens at age 4 years, was associated with an increased risk for FRS in adolescence. Peanuts and tree nuts were the most common culprit foods for anaphylaxis, and fruits and vegetables for non-anaphylactic reactions. Adolescents with anaphylaxis were significantly more likely to be sensitized to storage proteins (Ara h 2, Cor a 9, Cor a 14) and to be polysensitized to foods (P < 0.001 vs. non-anaphylactic reactions).

CONCLUSIONS AND CLINICAL RELEVANCE

The incidence of food-induced anaphylaxis during adolescence in our population-based birth cohort is higher than previously reported. Adolescents with anaphylaxis differ from adolescents with non-anaphylactic FRS with regard to culprit foods and sensitization. Adolescents with previous anaphylaxis are likely to be polysensitized to foods, particularly tree nut and peanut storage proteins, and which warrants consideration at follow-up.

Update on the usage and safety of epinephrine auto-injectors, 2017

Anaphylaxis is a serious, potentially fatal allergic reaction. Guidelines recommend prompt intramuscular injections of epinephrine as the first-line therapy for anaphylaxis. Delayed epinephrine treatment may cause undesirable clinical outcomes, including death. In the community, epinephrine auto-injectors (EAIs) are commonly used to treat anaphylaxis. This literature review examines several recent concerns regarding the safety of EAIs that may prevent the timely administration of epinephrine. Reports of cardiovascular complications are linked with epinephrine administration, although recent studies suggest that these events are much more commonly associated with intravenous epinephrine rather than with EAIs. Recent studies have also highlighted accidental injections of EAIs in patients’ or caregivers’ fingers and lacerations associated with the use of EAI in children. However, the data suggest that both accidental injections and lacerations are rare and require limited medical intervention. In addition, patients may receive conflicting information on the safety and efficacy of using expired EAIs. Overall, it is believed that the benefits of using EAIs far outweigh the potential risks of not administering an EAI. Although legitimate safety concerns are associated with EAIs, adverse events are rare. Continued training of medical providers, caregivers, and patients may be beneficial to address these concerns and reduce EAI-associated injuries while ensuring that patients receive necessary medical care.

Evaluation of Anaphylaxis Management in a Pediatric Emergency Department

OBJECTIVE

In 2006, the National Institute of Allergy and Infectious Disease established evidence-based treatment guidelines for anaphylaxis. The purpose of our study was to evaluate provider adherence to guidelines-based management for anaphylaxis in a tertiary care pediatric emergency department (ED).

METHODS

Retrospective chart review was conducted of patients (0-18 years) presenting to the Arkansas Children Hospital ED from 2004 to 2011 for the treatment of anaphylaxis using International Classification of Diseases, Ninth Edition, codes. Multiple characteristics including demographics, clinical features, allergen source, and anaphylaxis management were collected. Fisher exact or χ tests were used to compare proportion of patients treated with intramuscular (IM) epinephrine in the preguideline versus postguideline period. Relative risk (RR) statistics were computed to estimate the ratio of patients who received self-injectable epinephrine prescription and allergy follow-up in the preguideline and postguideline groups.

RESULTS

A total of 187 patients (median [range] age, 7 [1-18] years; 67% male; 48% African American) were evaluated. Food (44%) and hymenoptera stings (22%) were commonly described culprit allergens, whereas 29% had no identifiable allergen. Only 47% (n = 87) received epinephrine in the ED and 31% (n = 27) via the preferred IM route. Comparing postguideline (n = 126) versus preguideline (n = 61) periods demonstrated increase in the usage of the IM route (46% postguideline vs 6% preguideline; risk ratio (RR), 7.64; 95% confidence interval [CI], 2.04-46.0; P < 0.001). Overall, 61% (n = 115) of the patients received self-injectable epinephrine upon discharge, and there were no significant differences between the groups (64% postguideline vs 56% preguideline, P = 0.30). Postguideline patients were more likely to receive a prescription compared with preguideline patients (64% postguideline vs 56% preguideline; RR, 1.15; 95% CI, 0.89-1.55; P = 0.30). Only 45% (n = 85) received an allergy referral. Postguideline patients were more likely to receive an allergy referral than preguideline patients (48% postguideline vs 41% preguideline; RR, 1.16; 95% CI, 0.81-1.73; P = 0.40).

CONCLUSIONS

Provider use of IM epinephrine has improved since anaphylaxis guidelines were published. However, more provider education is needed to improve overall adherence of guidelines in a tertiary care pediatric ED.

Variation and Trends in Anaphylaxis Care in United States Children's Hospitals

OBJECTIVES

We sought to determine the extent of variation in treatment of children with anaphylaxis.

METHODS

We identified children 1 month to 18 years of age presenting with a primary diagnosis of anaphylaxis to one of the 35 pediatric hospitals included in the Pediatric Health Information System between January 1, 2009, and September 30, 2013. We evaluated the variation in use of β2 agonists, glucocorticoids, histamine-1 (H1) antagonists, histamine-2 (H2) antagonists, inhaled epinephrine, intravenous fluids, and oxygen. We assessed whether variation exists in the rates of hospitalization and 3-day emergency department (ED) revisits and whether a temporal trend exists in the ED visit rate for anaphylaxis.

RESULTS

Among 10,351 children with anaphylaxis, the hospital-level median use of common anaphylaxis therapies varied for β2 agonists (22%, interquartile range [IQR] = 16%-26%), glucocorticoids (71%, IQR = 65%-76%), H1 blockers (60%, IQR = 57%-65%), H2 blockers (53%, IQR = 36%-64%), inhaled epinephrine (2.2%, IQR = 1.3%-3.5%), intravenous fluids (26%, IQR = 13%-41%), and oxygen (2.6%, IQR = 0.8%-4.1%). Hospitalization rates ranged from 12% to 95%, with a median rate of 41%. Anaphylaxis diagnoses rose from 5.7 to 11.7 patients per 10,000 ED visits between 2009 and 2013 (p < 0.001 for trend).

CONCLUSIONS

There is substantial variability in the use of common therapies and hospitalization rates for children cared for in U.S. children's hospitals. Additionally, ED visits for children with anaphylaxis are increasing at U.S. children's hospitals. These findings highlight the need for research defining optimal care for anaphylaxis.

Review article: quality of follow-up care for anaphylaxis in the emergency department

The prevalence of allergic disorders is rising, with a corresponding increase in patients presenting to an ED with anaphylaxis. Appropriate follow up is required for patients with anaphylaxis. We reviewed two potential performance indicators for the quality of post-discharge care: (i) the rate of self-injectable adrenaline prescription; and (ii) the referral rate for follow-up care with allergy specialists. A search of Cochrane Library, PubMed and Google Scholar was performed using the following initial search string: anaphylaxis and 'emergency department'. We considered any (interventional or observational design) study assessing post-discharge care in anaphylaxis, measured by either adrenaline self-injection prescription or allergist referral. Subjects were patients with (suspected) anaphylaxis or severe allergic reaction, with no age limit. This review summarises findings from 16 relevant papers, all retrospective analyses of post-discharge care for anaphylaxis. Weighted arithmetic means were calculated for rates of prescription of adrenaline auto-injector and referral to an allergist following admission to an ED in patients with (suspected) anaphylaxis or severe allergic reaction. Prescription rates for self-injected adrenaline at the time of discharge following anaphylaxis varied from 0% to 68%, with a mean of 44%. Allergist referral rates ranged from 0% to 84%, with a mean of 33%. This review demonstrates that there is room for improvement in post-discharge care for patients who present to the ED with an anaphylactic reaction.

Glucocorticoids and Hospital Length of Stay for Children with Anaphylaxis: A Retrospective Study

OBJECTIVE

To evaluate whether glucocorticoid administration is associated with improved outcomes in children with anaphylaxis.

STUDY DESIGN

We included children from the Pediatric Health Information System database who were diagnosed with anaphylaxis at 35 US children's hospitals between 2009 and 2013. Patients were stratified by disposition from the emergency department (ED), either hospitalized or discharged. We evaluated the association between glucocorticoid administration and prolonged length of stay (LOS), defined as hospital stay ≥ 2 days, and subsequent epinephrine administration among hospitalized children. Among discharged children, we assessed the association between glucocorticoid administration and ED revisits within 3 days. Analyses were adjusted for illness severity using ordering of laboratory tests, medications, oxygen, intravenous fluids, and admission to the intensive care unit.

RESULTS

Among 5203 children hospitalized with anaphylaxis, 424 (8.2%) had prolonged LOS. Glucocorticoid administration was inversely associated with prolonged LOS (aOR, 0.61; 95% CI, 0.41-0.93) and with subsequent epinephrine use (aOR, 0.63; 95% CI, 0.43-0.84) among hospitalized children. Glucocorticoid administration was not associated with the odds of a 3-day revisit (aOR, 1.01; 95% CI, 0.50-2.05) among discharged patients.

CONCLUSION

The use of glucocorticoids was inversely associated with prolonged LOS among children hospitalized with anaphylaxis, but was not associated with 3-day ED revisits among discharged children. These findings support the use of glucocorticoids in children hospitalized with anaphylaxis.