Underreporting of anaphylaxis in a community emergency room

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].

Active surveillance and clinical analysis of anaphylaxis based on the China Hospital Pharmacovigilance System

Objective: This study aimed to develop active surveillance programs (ASPs) for anaphylaxis using the China Hospital Pharmacovigilance System (CHPS) and analyze the characteristics, allergens, and management strategies for anaphylaxis within a tertiary hospital setting in China. Methods: We retrospectively analyzed the anaphylaxis cases reported to the National Adverse Drug Reaction Monitoring System in our hospital from 2014 to 2021. Characteristic medical orders, progress notes, and diagnoses in these cases were recorded to identify initial anaphylaxis trigger entries. Based on these initial entries, the questionnaire was developed, and the Delphi method was used to establish consensus entries for anaphylaxis triggers. The CHPS was used to program these trigger entries and construct ASPs, which were then tested on the 238,194 discharged patients to evaluate their performance and analyze the related clinical data. Results: Ten anaphylaxis triggers and three ASPs were ultimately identified. The ASPs captured 309 cases, out of which 94 cases were confirmed as anaphylaxis following manual screening. After removing duplicates, we noted 76 patients who experienced anaphylaxis 79 times. The positive rate of triggers and the positive predictive value of the programs were 0.13% and 30.42%, respectively. The incidence of anaphylaxis in our study was 0.03%, and the number of anaphylaxis cases detected by the ASPs was 5.64 times higher than those detected by the spontaneous reporting system. Anaphylaxis was more common among female patients. Antibacterial drugs, antineoplastic drugs, and contrast media were the most prevalent allergens in clinical practice. Anaphylaxis to antineoplastic drugs had the highest incidence (0.6%) when compared with patients admitted during the same period. Our study revealed a significant underuse of epinephrine and overuse of second-line therapy (glucocorticoids and antihistamines) in the management of anaphylaxis. Furthermore, we found the use and dosage of epinephrine to be inappropriate. Conclusion: The CHPS can effectively utilize both structured and unstructured data to construct anaphylaxis ASPs, and this could counteract the under-reporting by the spontaneous reporting system, the primary adverse reaction monitoring method in China. The treatment and management of anaphylaxis are currently inadequate and require improvement to reduce mortality risk.

Health-care resource utilization associated with peanut allergy management under allergen avoidance among commercially insured individuals

Background: Until recently, the standard approach to care for individuals with peanut allergy (PA) was limited to allergen avoidance and treatment of reactions with emergency medicines. Objectives: To assess health-care resource utilization (HRU) and costs associated with PA management under allergen avoidance and to identify risk factors associated with peanut reactions that resulted in inpatient (IP) and/or emergency department (ED) visits. Methods: Privately insured individuals with PA diagnosis codes were identified from a large U.S. administrative claims data base (January 1, 1999, to March 31, 2017). PA-related HRU, indicated by a PA diagnosis and/or diagnostic procedure codes and by epinephrine autoinjectors (EAI) prescription fills in medical and pharmacy claims, respectively, and all-cause costs were described per patient-year (PPY). Risk factors associated with peanut reactions in an IP and/or ED setting were identified by using a multivariable logistic regression model. Results: A total of 86,483 patient-years from 14,136 individuals with PA were included. At the patient-year level, 28.1% were ages 0-3 years, 43.6% were ages 4-11 years, 13.7% were ages 12-17 years, and 14.5% were ages ≥ 18 years; 35.6% had PA-related outpatient visits; 50.6% had EAI fills; and 2.4% had PA-related IP and/or ED visits PPY. Younger individuals had more PA-related outpatient visits and EAI fills, with peak intensive use at ages 4-11 years. The proportion of individuals with PA-related IP and/or ED visits was highest among those aged ≥ 18 years. Mean all-cause costs were $3084 PPY; individuals with PA-related IP and/or ED visits incurred $8902 PPY ($17,451 for those with one or more IP visits). Risk factors associated with peanut reactions that resulted in IP and/or ED visits included young adults (odds ratio [OR] 3.19 [95% confidence interval {CI}, 2.66-3.83]), previous peanut reaction(s) (OR 1.66 [95% CI, 1.23-2.24]), asthma (OR 1.33 [95% CI, 1.18-1.51]), and male sex (OR 1.14 [95% CI, 1.01-1.28]). Conclusion: Individuals with PA and under allergen avoidance had significant HRU that varied across all age groups, with more PA-related outpatient visits during preschool and/or school age and PA-related urgent care among adults. Individuals with previous peanut reaction(s), asthma, and males had a higher risk of peanut reactions that resulted in IP and/or ED visits.

Idiopathic Anaphylaxis: A Form of Mast Cell Activation Syndrome

Idiopathic anaphylaxis is a condition caused by paroxysmal episodes of sudden-onset multiorgan involvement variably including laryngeal edema, urticaria, bronchoconstriction, dyspnea, hypoxia, abdominal pain, nausea, vomiting, diarrhea, and hypotension. Rarely, the episodes can lead to cardiovascular collapse and death in the absence of a clear trigger, especially in the presence of other cardiovascular comorbidities. Elevated mast cell mediators such as tryptase and histamine have been reported during episodes, and mast cells are considered the primary cells responsible for driving anaphylaxis in humans. Basophils also secrete histamine and LTC4 when activated and theoretically can contribute to symptoms. As our understanding of mast cell disorders continue to grow, the classification for these disorders evolves. The purpose of this article was 2-fold: to review the epidemiology, clinical manifestations, and diagnosis of idiopathic anaphylaxis and to discuss the classification of idiopathic anaphylaxis within the broader context of mast cell activation disorders.

Economic burden of peanut allergy in pediatric patients with evidence of reactions to peanuts in the United States

BACKGROUND: The economic burden of food allergy is large; however, costs specific to individuals with peanut allergy experiencing reactions to peanuts remain to be evaluated. As the prevalence of peanut allergy continues to increase in children, a better understanding of the cost of care is warranted. OBJECTIVE: To assess the cost of care of peanut allergy among privately insured and Medicaid-insured pediatric patients in the United States. METHODS: This retrospective matched-cohort study included patients aged 4-17 years from the Optum Health Care Solutions and Medicaid Claims databases (January 1, 2007-March 31, 2017). Patients were classified into 2 cohorts: peanut allergy (with peanut allergy diagnosis codes and reactions triggering health care resource utilization [HRU]) and peanut allergy-free (no peanut allergy diagnosis codes in claims). Peanut allergy patients were matched 1:10 to peanut allergy-free patients based on baseline covariates. Comorbidities including anxiety and depression, HRU, and direct health care costs were compared between cohorts and reported for both perspectives separately. RESULTS: Compared with peanut allergy-free patients (n = 30,840 privately insured; n = 12,450 Medicaid), peanut allergy patients (n = 3,084 privately insured; n = 1,245 Medicaid) had higher prevalence of asthma, atopic dermatitis/eczema, other food allergies, allergic rhinitis, depression, and anxiety (all P < 0.01). Peanut allergy patients had higher HRU per patient per year (PPPY), including 90% more emergency department visits among both privately insured and Medicaid patients (P < 0.01) and higher direct health care costs PPPY, with incremental costs of $2,247 total or $1,712 excluding asthma-related costs for privately insured patients and $2,845 total or $1,844 excluding asthma-related costs for Medicaid patients (all P < 0.01). CONCLUSIONS: Pediatric patients in the United States with peanut allergy and reactions triggering HRU had significantly higher comorbidity burdens, HRU, and direct health care costs, regardless of asthma-related costs, versus those without peanut allergy. DISCLOSURES: This study was funded by Aimmune Therapeutics, a Nestlé Health Science company. The study sponsor was involved in several aspects of the research including the study design, the interpretation of data, the writing of the manuscript, and the decision to submit the manuscript for publication. Yu and Tilles are employees of Aimmune Therapeutics, a Nestlé Health Science company. Robison and Norrett were employees of Aimmune Therapeutics at the time this study was conducted. Blaiss, Meadows, and Hass provided paid consulting services to Aimmune Therapeutics. Guerin and Latremouille-Viau are employees of Analysis Group, a consulting company that provided paid consulting services to Aimmune Therapeutics. Parts of the results were presented at the AMCP Managed Care & Specialty Pharmacy Annual Meeting held March 25-28, 2019, in San Diego, CA, and at the ISPOR Annual Meeting held May 18-22, 2019, in New Orleans, LA.

Anaphylaxis-a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis

Anaphylaxis is an acute, potential life-threatening systemic allergic reaction that may have a wide range of clinical manifestations. Severe anaphylaxis and/or the need for repeated doses of epinephrine to treat anaphylaxis are risk factors for biphasic anaphylaxis. Antihistamines and/or glucocorticoids are not reliable interventions to prevent biphasic anaphylaxis, although evidence supports a role for antihistamine and/or glucocorticoid premedication in specific chemotherapy protocols and rush aeroallergen immunotherapy. Evidence is lacking to support the role of antihistamines and/or glucocorticoid routine premedication in patients receiving low- or iso-osmolar contrast material to prevent recurrent radiocontrast media anaphylaxis. Epinephrine is the first-line pharmacotherapy for uniphasic and/or biphasic anaphylaxis. After diagnosis and treatment of anaphylaxis, all patients should be kept under observation until symptoms have fully resolved. All patients with anaphylaxis should receive education on anaphylaxis and risk of recurrence, trigger avoidance, self-injectable epinephrine education, referral to an allergist, and be educated about thresholds for further care.

Anaphylaxis diagnosis and management in the Emergency Department of a tertiary hospital in the Philippines

Background

In the Emergency Department (ED), diagnosis and management of anaphylaxis are challenging with at least 50% of anaphylaxis episodes misdiagnosed when the diagnostic criteria of current guidelines are not used.

Objective

Objective of our study was to assess anaphylaxis diagnosis and management in patients presenting to the ED.

Methods

Retrospective chart review conducted on patients presenting to The Medical City Hospital ED, the Philippines from 2013–2015 was done. Cases were identified based on International Statistical Classification of Diseases, 10th revision coding for either anaphylaxis or other allergic related diagnosis. Cases fitting the definition of anaphylaxis as identified by the National Institute of Allergy and Infectious Disease and the Food Allergy and Anaphylaxis Network (NIAID/FAAN) were included. Data collected included demographics, signs and symptoms, triggers and management.

Results

A total of 105 cases were evaluated. Incidence of anaphylaxis for the 3-year study period was 0.03%. Of the 105 cases, 35 (33%) were diagnosed as “urticaria” or “hypersensitivity reaction” despite fulfilling the NIAID/FAAN anaphylaxis criteria. There was a significant difference in epinephrine administration between those given the diagnosis of anaphylaxis versus misdiagnosed cases (61 [87%] vs. 12 [34%], χ² = 30.77, p < 0.01); and a significant difference in time interval from arrival at the ED to epinephrine administration, with those diagnosed as anaphylaxis (48%) receiving epinephrine within 10 minutes, versus ≥ 60 minutes for most of the misdiagnosed group (χ² = 52.97, p < 0.01).

Conclusion

Despite current guidelines, anaphylaxis is still misdiagnosed in the ED. Having an ED diagnosis of anaphylaxis significantly increases the likelihood of epinephrine administration, and at a shorter time interval.

Capturing anaphylaxis through medical records: Are ICD and CPT codes sufficient?

OBJECTIVE

The identification of anaphylaxis cases is imperative for optimal clinicalprovider knowledge deficiencies in diagnosis and treatment and the efficacy of reimbursement codes, such as International Classification of Diseases (ICD) and current procedural terminology (CPT) codes, in detecting anaphylaxis.

DATA SOURCES

Pubmed.

STUDY SELECTIONS

Recent and clinically relevant literature on anaphylaxis and provider knowledge, ICD, CPT, Healthcare Common Procedural Coding System (HCPCS), and E-codes were selected and reviewed.

RESULTS

Reimbursement codes are used to detect anaphylaxis in administrative claims databases. Inaccurate recognition of the diagnosis by providers, underreporting, and cause identification are challenges faced by health researchers using reimbursement codes for anaphylaxis case identification. Anaphylactic shock-specific ICD codes were noted to have a positive predictive value (PPV) of 52% to 53% of anaphylaxis events compared with physician chart review, which was improved to 63% to 67.3% when used in conjunction with anaphylaxis symptom-specific ICD, CPT, HCPCS, and E-codes 31, 34, and 35.

CONCLUSION

Education of providers to properly diagnose and treat anaphylaxis requires systematic and educational investments. The ICD codes specific to anaphylactic shock have suboptimal PPV to identify anaphylaxis in administrative claims databases. Use of algorithms incorporating other reimbursement codes improve the PPV, but they are limited by inaccurate diagnoses and underreporting of anaphylaxis. Future ICD-11 reclassification may improve anaphylaxis detection by reimbursement codes.

Medical malpractice related to drug-induced anaphylaxis: An analysis of lawsuit judgments in South Korea

Drug-induced anaphylaxis (DIA) is a highly paradoxical disorder involving a fatal response to medicines prescribed for therapeutic purposes. This study aimed to improve the awareness on DIA and to prevent errors through an analysis of lawsuit judgments.Sentenced judgments involving DIA from 1998 to 2017 using the database of the Korean Supreme Court Judgment System were collected. General characteristics, results, and recognized negligence of DIA litigation cases were analyzed.Of 27 lawsuit cases included, antibiotics (n = 6, 22.2%), radiocontrast media (n = 6, 22.2%), and non-steroidal anti-inflammatory drugs (n = 5, 18.5%) were the most common drugs that had caused DIA. Cardiac arrest was reported in 23 cases (85.2%). The median time interval from drug administration to diagnosis and from diagnosis to cardiac arrest were 7 (interquartile range, IQR = 0-35) and 5 minutes (IQR = 0-33), respectively, suggesting insufficient time to cope with anaphylaxis. Consequently, either death (n = 18, 66.7%) or ischemic brain injury (n = 9, 33.3%) occurred in all cases. Violation of duty of care was recognized in 19 cases (70.4%) with median awarded amount of $106,060 (IQR = $70,296-$168,363). The recognized negligence included inadequate observation after drug administration (n = 6), delayed or missed epinephrine administration (n = 6), ignoring a history of allergy or drug hypersensitivity (n = 6), and prescription error (n = 5).It is necessary to improve the awareness on DIA, because making a trivial error in any process of history taking, drug prescription and administration, observation, and/or emergency treatment may have fatal consequences that can lead to indemnity.

Evaluation of the Potential Risk Factors for Drug-Induced Anaphylaxis in Adult Patients

AIM

To investigate the potential risk factors in patients who have experienced anaphylaxis from drugs.

METHOD

The study included 281 adult patients (median age 40 years; 76.5% female) who experienced immediate types of hypersensitivity reaction to a drug. The patients were divided into an anaphylaxis group and a nonanaphylaxis group. The anaphylaxis group was diagnosed according to the criteria of the World Allergy Organization. Skin testing with culprit drugs was performed. In the nonanaphylaxis group, drug provocation tests were performed with culprit drugs, including aspirin or diclofenac, to determine nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity. Atopy was determined by skin prick tests with the common inhalant allergens. Patients' demographics, clinical features, and baseline tryptase and total IgE levels were compared between the 2 groups.

RESULTS

The median interval between the last reaction in the patient's history and the study evaluation was 7 months (range 1-120 months). In 52.3% of the patients, reactions were defined as anaphylaxis. The most common culprit drugs were NSAIDs (56.9%) and β-lactams (34.7%). The culprit drugs were used parenterally in 13.2% of the patients. 34.9% of the patients had comorbid diseases and 24.6% used additional drugs, the most common being antihypertensives (10%). Atopy was determined in 28.8% and 28.1% of the patients were smokers. The median serum level of baseline tryptase and total IgE was 3.5 µg/L and 77 kU/L, respectively. In 46.3% of the patients, skin tests with culprit drugs were positive and the positivity ratio was higher in the anaphylaxis group (p = 0.002). Anapyhlaxis was more common in patients who were: hypertensive, atopic, using angio-tensin-converting enzyme inhibitors/angiotensin receptor blockers, and received the culprit drug parenterally (p = 0.034, p = 0.04, p = 0.03, p = 0.035, p = 0.013, and p < 0.001). In the multivariate analysis, it was observed that the parenteral usage of the drug and the presence of atopy were significantly higher in the anaphylaxis group (p < 0.001, odds ratio [OR] = 20.05, confidence interval [CI] 4.75-88.64; p = 0.012, OR = 2.1, CI 1.17-3.74). Age, smoking, family history, and serum levels of baseline tryptase and total IgE did not differ between groups.

CONCLUSION

The parenteral route and atopy increase the risk of drug-induced anaphylaxis. IgE-mediated sensitivity to the culprit drug seems to facilitate anaphylaxis.

Exercise-Induced Anaphylaxis: Literature Review and Recent Updates

PURPOSE OF REVIEW

This paper will review the pathophysiology, diagnosis, and treatment of exercise-induced anaphylaxis and food-dependent, exercise-induced anaphylaxis with an emphasis on novel studies published in the past several years.

RECENT FINDINGS

Exercise-induced anaphylaxis (EIAn) is a clinical syndrome characterized by anaphylaxis during or shortly after physical exertion. The syndrome is broadly grouped into two categories: exercise-induced anaphylaxis and food-dependent, exercise-induced anaphylaxis (FDEIAn). Recent literature indicates that FDEIAn is a primary IgE-mediated food allergy which is augmented by several cofactors. Cofactors such as exercise, NSAIDs, and alcohol increase intestinal permeability and allow increased antigen uptake, thereby causing symptoms. The pathophysiology of EIAn is still under investigation. EIAn and FDEIAn are rare clinical syndromes characterized by symptoms during or shortly after exercise. Despite recent advances in the understanding of EIAn and FDEIAn, the pathophysiology of both conditions is not fully understood.

Epidemiology, Mechanisms, and Diagnosis of Drug-Induced Anaphylaxis

Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release of mediators by mast cells and basophils. Although anaphylaxis is often under-communicated and thus underestimated, its incidence appears to have risen over recent decades. Drugs are among the most common triggers in adults, being analgesics and antibiotics the most common causal agents. Anaphylaxis can be caused by immunologic or non-immunologic mechanisms. Immunologic anaphylaxis can be mediated by IgE-dependent or -independent pathways. The former involves activation of Th2 cells and the cross-linking of two or more specific IgE (sIgE) antibodies on the surface of mast cells or basophils. The IgE-independent mechanism can be mediated by IgG, involving the release of platelet-activating factor, and/or complement activation. Non-immunological anaphylaxis can occur through the direct stimulation of mast cell degranulation by some drugs, inducing histamine release and leading to anaphylactic symptoms. Work-up of a suspected drug-induced anaphylaxis should include clinical history; however, this can be unreliable, and skin tests should also be used if available and validated. Drug provocation testing is not recommended due to the risk of inducing a harmful reaction. In vitro testing can help to confirm anaphylaxis by analyzing the release of mediators such as tryptase or histamine by mast cells. When immunologic mechanisms are suspected, serum-sIgE quantification or the use of the basophil activation test can help confirm the culprit drug. In this review, we will discuss multiple aspects of drug-induced anaphylaxis, including epidemiology, mechanisms, and diagnosis.

Drug-induced anaphylaxis in the emergency room

Anaphylaxis is a life‐threatening, systemic allergic reaction that presents unique challenges for emergency care practitioners. Anaphylaxis occurs more frequently than previously believed. Therefore, proper knowledge regarding the epidemiology, mechanisms, symptoms, diagnosis, and treatment of anaphylaxis is essential. In particular, the initial treatment strategy, followed by correct diagnosis, in the emergency room is critical for preventing fatal anaphylaxis, although making a diagnosis is not easy because of the broad and often atypical presentation of anaphylaxis. To this end, the clinical criteria proposed by the National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network are useful, which, together with a differential diagnosis, could enable a more accurate diagnosis. Additional in vitro tests, such as plasma histamine and tryptase measurements, are also helpful. It should be emphasized that adrenaline is the only drug recommended as first‐line therapy in all published national anaphylaxis guidelines. Most international anaphylaxis guidelines recommend injecting adrenaline by the intramuscular route in the mid‐anterolateral thigh, whereas i.v. adrenaline is an option for patients with severe hypotension or cardiac arrest unresponsive to intramuscular adrenaline and fluid resuscitation. In addition to the route of administration, choosing the appropriate dose of adrenaline is essential, because serious adverse effects can potentially occur after an overdose of adrenaline. Furthermore, to avoid future recurrence of anaphylaxis, providing adrenaline auto‐injectors and making an etiological diagnosis, including confirmation of the offending trigger, are recommended for patients at risk of anaphylaxis before their discharge from the emergency room.

Changes in Food-Specific IgE Over Time in the National Health and Nutrition Examination Survey (NHANES)

BACKGROUND

Food allergy prevalence appears to have recently risen, with larger increases among non-Hispanic blacks. However, it is unclear whether these trends represent shifts in recognition of food allergy or in sensitization.

OBJECTIVE

The objective of this study was to determine whether sensitization to common food allergens increased in US children from 1988-1994 to 2005-2006 and whether these trends differed by race and/or ethnicity.

METHODS

Food-specific immunoglobulin E (IgE; to peanut, milk, egg, and shrimp) was measured by ImmunoCAP in stored sera from subjects aged 6-19 in the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and was compared with NHANES 2005-2006. Sensitization to foods was defined as overall (IgE ≥ 0.35 kU/L), moderate level (IgE ≥ 2 kU/L), and high level (IgE ≥ commonly used 95% predictive values). Sensitization to individual and combined foods was compared between surveys, with analyses further stratified by race and/or ethnicity.

RESULTS

A total of 7896 subjects (NHANES III: n = 4995, NHANES 2005-2006: n = 2901) were included. In NHANES III, the prevalence of food sensitization was 24.3% (95% confidence interval [CI]: 22.1-26.5) compared with 21.6% (95% CI: 19.5-23.7) in NHANES 2005-2006. There were no significant changes in the prevalence of any level of milk, egg, or peanut sensitization, but shrimp sensitization at all levels decreased markedly; overall sensitization NHANES III: 11.2% (95% CI: 10.0-12.5) versus NHANES 2005-2006: 6.1% (95% CI: 4.5-7.7). There was a trend toward the increased prevalence of moderate- and high-level sensitization to the combination of milk, egg, and peanut among non-Hispanic blacks but not other groups.

CONCLUSIONS

In contrast to our expectations, sensitization to common food allergens did not increase between the late 1980s/early 1990s and the mid-2000s among US 6-19 year olds, and in fact decreased to shrimp.

Risk multipliers for severe food anaphylaxis

Anaphylaxis is a severe, life threatening allergic reaction. In most fatal cases of food anaphylaxis, the fatality is not due merely to a simple, linear relationship between the allergen and exposure in a sensitized individual. Compounding factors such as the allergic disease burden—particularly the presence of asthma; comprehension of the potential severity of an event, training in the appropriate use of epinephrine, and emerging metabolic factors should be considered when assessing risk and establishing management strategies. This paper reviews the factors that contribute to the risk of severe anaphylactic events and provides a framework for the ongoing management of patients at risk of severe food allergy.

Pediatric emergency department visits and hospitalizations due to food-induced anaphylaxis in Illinois

BACKGROUND

Rates of food-induced anaphylaxis among children remain uncertain. In addition, little is known about the demographics of children who have experienced food-induced anaphylaxis resulting in emergency department (ED) visits and/or subsequent hospitalizations.

OBJECTIVES

To evaluate trends in ED visits and hospital admissions due to food-induced anaphylaxis among Illinois children and to identify socioeconomic variation in trend distribution.

METHODS

Illinois hospital discharge data compiled by the Illinois Hospital Association were used to identify ED visits or hospitalizations for food-induced anaphylaxis in Illinois hospitals from 2008-2012. Data for children aged 0 to 19 years who were Illinois residents and received a diagnosis of food-induced anaphylaxis based on International Classification of Diseases, Ninth Revision, Clinical Modification codes (995.60 through 995.69) were included for analysis.

RESULTS

There was a significant increase in the rate of ED visits and hospital admissions due to food-induced anaphylaxis among children in Illinois during the 5-year period, with an annual percent increase of 29.1% from 6.3 ED visits and hospital admissions per 100,000 children in 2008 to 17.2 in 2012 (P < .001). Increases in visit frequency were observed for all study variables, including age, sex, race/ethnicity, insurance type, metropolitan status, hospital type, and allergenic food. Visits were most frequent each year for Asian children and children with private insurance. However, the annual percent increase in visits was most pronounced among Hispanic children (44.3%, P < .001) and children with public insurance (30.2%, P < .001).

CONCLUSION

ED visits and hospital admissions for food-induced anaphylaxis have increased during a 5-year period among children in Illinois, regardless of race/ethnicity and socioeconomic status.

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.

Predictors of Repeat Epinephrine Administration for Emergency Department Patients with Anaphylaxis

BACKGROUND

Risk factors that predict which patients with anaphylaxis might require repeat doses of epinephrine are poorly understood.

OBJECTIVE

The objective of this study was to identify risk factors associated with the need for multiple doses of epinephrine during an anaphylactic reaction.

METHODS

Patients were included if they met diagnostic criteria for anaphylaxis on presentation to the emergency department (ED) at our academic medical center between April 2008 and February 2014. Data were collected on allergic history, presenting signs and symptoms, anaphylaxis management, and disposition. Univariable and multivariable analyses were performed to estimate associations between possible risk factors and the need for multiple doses.

RESULTS

Of 582 ED patients with anaphylaxis, 45 (8%) required multiple doses of epinephrine. By multivariable analysis, factors associated with the need for repeat doses were a history of anaphylaxis (odds ratio [OR], 2.5 [95% CI, 1.3-4.7]; P = .005), the presence of flushing or diaphoresis (OR, 2.4 [95% CI, 1.3-4.5]; P = .007), and the presence of dyspnea (OR, 2.2 [95% CI, 1.0-5.0]; P = .046). Patients who received more than 1 dose were more likely to be admitted to the general medical floor (OR, 2.8 [95% CI, 1.1-7.2]; P = .03) or intensive care unit (OR, 7.6 [95% CI, 3.7-15.6]; P < .001).

CONCLUSION

Patients with a history of anaphylaxis, flushing or diaphoresis, or dyspnea may require multiple doses of epinephrine to treat anaphylactic reactions. Patients who require more than 1 dose are more likely to be admitted to the hospital, thus increasing health care resource utilization.

Management and treatment of anaphylaxis in children: still too low the rate of prescription and administration of intramuscular epinephrine

Despite it being well known that anaphylaxis is a severe life-threatening reaction requiring prompt management and treatment, this entity is still under-recognized and not correctly managed, above all in children. The aim of this study was to analyze the most frequent features of anaphylaxis in a pediatric population (n=65 patients) and to identify factors predicting more severe reactions. Among the 70 recorded episodes, food was the main culprit of anaphylaxis, and patients with a positive history for allergic asthma had more severe episodes (P=0.008). A self-injectable adrenaline was used only in 2 of the 70 episodes and none of the 50 episodes managed in the Emergency Department was treated with intramuscular adrenaline. Only 10/65 patients (15&#x0025;) had a prescription for an auto-injector prior to the first episode of anaphylaxis. The retrospective analysis of the risk factors potentially requiring an epinephrine auto-injector prescription before the first anaphylactic episode, showed that of the 55 patients without prescription, at least 10 (18&#x0025;) should have been provided with a device, according to the most recent guidelines. In conclusion, notwithstanding intramuscular adrenaline being the first-line treatment of anaphylaxis, many episodes are still undertreated and the risk of anaphylaxis is still under-estimated. More efforts should be made to promote the correct management of anaphylaxis among both healthcare-providers and patients.

Food allergy diagnosis and management practices among pediatricians

Our goals were to (1) estimate the rates of parent-reported versus physician-diagnosed food allergy, (2) determine pediatrician adherence to national guidelines, and (3) obtain pediatricians' perspectives on guideline nonadherence. A mixed method approach was used, including survey, chart review, and qualitative methods. Overall, 10.9% of parents reported having a child with food allergy and two thirds of these cases were detected by the pediatrician. Chart reviews revealed high rates of guideline adherence with respect to allergist referral (67.3%), but less consistent adherence regarding documentation of reaction history (38.8%), appropriate use of diagnostic tests (34.7%), prescription of epinephrine autoinjectors (44.9%), and counseling families in food allergy management (24.5%). Pediatricians suggested that poor adherence was due to lack of documentation, familiarity with guidelines, and clarity regarding the pediatrician's role in managing food allergy. Findings emphasize the need to better establish the role of the pediatrician and to improve awareness and adherence to guidelines.

Anaphylaxis on the other front line: perspectives from the emergency department

Although most cases of anaphylaxis are treated in the emergency department (ED), personnel may not immediately recognize anaphylaxis based on presenting symptoms because it has a wide range of clinical manifestations and variable progression. When symptoms happen to be atypical or mild and when no trigger is identified, the diagnosis of anaphylaxis can be challenging. Underdiagnosis of anaphylaxis can lead to delayed use of appropriate first-line epinephrine in favor of treatments that should be used as adjunctive only. Even when anaphylaxis is recognized, the choice between an epinephrine autoinjector or epinephrine ampule can still present a challenge. Treatment of anaphylaxis in the ED should include a combination of intramuscular epinephrine, supplemental oxygen, and intravenous fluids. If there is an incomplete response to the initial dose of epinephrine, additional doses or other measures may be considered. The most important management consideration is avoiding treatment delays, because symptoms can progress rapidly. Upon discharge from the ED, all patients with anaphylaxis should be given a prescription for at least 2 epinephrine autoinjectors, an initial emergency action plan, education about avoidance of triggers, and a referral to an allergist. A significant limitation of current studies is that clinical outcomes in anaphylaxis associated with established poor rates of diagnosis and use of recommended treatments are unclear; such trials must be conducted as supporting evidence for ED management guidelines for anaphylaxis.

Anaphylaxis knowledge and practice preferences of pediatric emergency medicine physicians: a national survey

OBJECTIVES

To assess the knowledge and practice preferences of anaphylaxis in pediatric emergency medicine (PEM) physicians by practice setting, and to identify factors associated with intramuscular (IM) epinephrine administration and admission of patients with anaphylaxis.

STUDY DESIGN

The cohort was a cross-sectional convenience sample; potential participants were recruited using contact information obtained from the American Board of Pediatrics and American Board of Medical Specialties membership databases and were asked to complete a 12 item survey. Board-certified PEM physicians were categorized by practice setting: university hospital, non-university hospital with a residency training program, or community hospital with no residency training program. Management practices based on practice setting are presented as proportions. Multivariate logistic regression identified factors associated with IM epinephrine administration and admission of patients with anaphylaxis for observation.

RESULTS

Of the 1114 PEM physicians solicited, 620 (56%) completed the survey. The majority (93.5%) correctly identified epinephrine as the treatment of choice for anaphylaxis, yet only 66.9% used the IM route of administration, and only 37.4% admitted affected patients for observation. Factors associated with the use of IM epinephrine included the presence of a residency program at the site of care (OR, 2.28, 95% CI, 1.3-4.04) and higher volume of anaphylaxis cases (OR, 1.21; 95% CI, 1.06-1.38). Increasing anaphylaxis case volume was associated with decreased likelihood of admission of patients with anaphylaxis (OR, 0.81; 95% CI, 0.72-0.92).

CONCLUSION

Even though the majority of PEM physicians correctly report using epinephrine in pediatric anaphylaxis, not all use the preferred administration route, and many discharge patients home after an abbreviated period.

Evaluating the management of anaphylaxis in US emergency departments: Guidelines vs. practice

BACKGROUND

Anaphylaxis is characterized by acute episodes of potentially life-threatening symptoms that are often treated in the emergency setting. Current guidelines recommend: 1) quick diagnosis using standard criteria; 2) first-line treatment with epinephrine; and 3) discharge with a prescription for an epinephrine auto-injector, written instructions regarding long-term management, and a referral (preferably, allergy) for follow-up. However, studies suggest low concordance with guideline recommendations by emergency medicine (EM) providers. The study aimed to evaluate how emergency departments (EDs) in the United States (US) manage anaphylaxis in relation to guideline recommendations.

METHODS

This was an online anonymous survey of a random sample of EM health providers in US EDs.

RESULTS

Data analysis included 207 EM providers. For respondent EDs, approximately 9% reported using agreed-upon clinical criteria to diagnose anaphylaxis; 42% reported administering epinephrine in the ED for most anaphylaxis episodes; and <50% provided patients with a prescription for an epinephrine auto-injector and/or an allergist referral on discharge. Most provided some written materials, and follow-up with a primary care clinician was recommended.

CONCLUSIONS

This is the first cross-sectional survey to provide "real-world" data showing that practice in US EDs is discordant with current guideline recommendations for the diagnosis, treatment, and follow-up of patients with anaphylaxis. The primary gaps are low (or no) utilization of standard criteria for defining anaphylaxis and inconsistent use of epinephrine. Prospective research is recommended.

Anaphylaxis

PURPOSE OF REVIEW

This article aims to make a review of the up-to-date knowledge on anaphylaxis and outline the recent advances on pathophysiology, diagnosis, and management of anaphylaxis.

RECENT FINDINGS

New data confirm the increase in prevalence of anaphylaxis and emphasize immunopathologic mechanisms. However, anaphylaxis is often underdiagnosed and guidelines are poorly applied, particularly in emergency departments.

SUMMARY

An improvement of rapid diagnosis and treatment combined with education of population will decrease mortality and morbidity of anaphylaxis.

Epinephrine auto-injector pandemic

Epinephrine is crucial in the treatment of anaphylaxis. As anaphylaxis frequently occurs in nonmedical settings, use of an epinephrine auto-injector is vital for prompt management. This article provides an overview of the increasing number of epinephrine auto-injector prescriptions and the underlying causes and contributing factors to these rising prescriptions. It also reviews the current indications for prescription of an epinephrine auto-injector, proper use of epinephrine auto-injectors, and the management of unintentional epinephrine injections.

Insect stings: clinical features and management

BACKGROUND

In human beings, local and systemic reactions can be caused both by blood-sucking insects and by venomous insect stings. In Central Europe, the insects that most commonly cause such reactions are honeybees, certain social wasps, mosquitoes, and flies.

METHODS

This article is based on a selective literature review, including guidelines from Germany and abroad.

RESULTS

Insect venom induces a toxic reaction at the site of the sting. Large local reactions are due to allergy and occur in up to 25% of the population; as many as 3.5% develop IgE-mediated, potentially life-threatening anaphylaxis, of which about 20 people die in Germany each year. Mastocytosis is found in 3% to 5% of patients with sting anaphylaxis, rendering these patients prone to very severe reactions. Blood-sucking by hematophagous insects can elicit a local allergic reaction, presenting as a wheal or papule, in at least 75% of the population. Large local reactions may ensue, but other diseases are rare. The acute symptoms of an insect sting are treated symptomatically. Patients who have had a systemic reaction or a large local reaction due to insect allergy must take permanent measures to avoid further allergen contact, and to make sure they can treat themselves adequately if stung again. Most patients with systemic anaphylactic reactions to bee or wasp stings need specific immunotherapy.

CONCLUSION

Insect stings can cause severe disease. Anaphylaxis due to bee or wasp stings is not a rare event; specific immunotherapy protects susceptible persons from further, potentially life-threatening reactions.

NIAID-sponsored 2010 guidelines for managing food allergy: applications in the pediatric population

Data from many studies have suggested a rise in the prevalence of food allergies during the past 10 to 20 years. Currently, no curative treatments for food allergy exist, and there are no effective means of preventing the disease. Management of food allergy involves strict avoidance of the allergen in the patient's diet and treatment of symptoms as they arise. Because diagnosis and management of the disease can vary between clinical practice settings, the National Institute of Allergy and Infectious Diseases (NIAID) sponsored development of clinical guidelines for the diagnosis and management of food allergy. The guidelines establish consensus and consistency in definitions, diagnostic criteria, and management practices. They also provide concise recommendations on how to diagnose and manage food allergy and treat acute food allergy reactions. The original guidelines encompass practices relevant to patients of all ages, but food allergy presents unique and specific concerns for infants, children, and teenagers. To focus on those concerns, we describe here the guidelines most pertinent to the pediatric population.

Evaluation of national institute of allergy and infectious diseases/food allergy and anaphylaxis network criteria for the diagnosis of anaphylaxis in emergency department patients

BACKGROUND

Diagnostic criteria were proposed at the Second Symposium on the Definition and Management of Anaphylaxis convened by the National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network (NIAID/FAAN). Validation is needed before these criteria can be widely adapted into clinical practice.

OBJECTIVE

Our aim was to retrospectively assess the diagnostic accuracy of the NIAID/FAAN criteria for the diagnosis of anaphylaxis in emergency department (ED) patients.

METHODS

A retrospective cohort study of ED patients presenting from April to October 2008 was conducted. Patients given a diagnosis of an allergic reaction or anaphylaxis and a subset of patients with related diagnoses were included. Electronic medical records were reviewed and data were abstracted to determine whether the NIAID/FAAN criteria were met. Records were also independently reviewed in a blinded fashion by 2 experienced attending allergists. Final diagnosis by allergists was considered the reference standard.

RESULTS

Of 214 patients, 86 (40.2%) met the NIAID/FAAN criteria for anaphylaxis. Allergists gave 61 (28.5%) patients diagnoses of anaphylaxis, 59 (96.7%) of whom satisfied the NIAID/FAAN criteria. The interrater agreement between allergists was substantial (κ = 0.77). The test characteristics of the NIAID/FAAN criteria were as follows: sensitivity, 96.7% (95% CI, 88.8% to 99.1%); specificity, 82.4% (95% CI, 75.5% to 87.6%); positive predictive value, 68.6% (95% CI, 58.2% to 77.4%); negative predictive value, 98.4% (95% CI, 94.5% to 99.6%); positive likelihood ratio, 5.48; and negative likelihood ratio, 0.04.

CONCLUSIONS

These results suggest that the NIAID/FAAN criteria are highly sensitive but less specific and are likely to be useful in the ED for the diagnosis of anaphylaxis.

Improving anaphylaxis management in a pediatric emergency department

BACKGROUND

The management of anaphylaxis in pediatric emergency units (PEU) is sometimes deficient in terms of diagnosis, treatment, and subsequent follow-up. The aims of this study were to assess the efficiency of an updated protocol to improve medical performance, and to describe the incidence of anaphylaxis and the safety of epinephrine use in a PEU in a tertiary hospital.

METHODS

We performed a before-after comparative study with independent samples through review of the clinical histories of children aged <14 years old diagnosed with anaphylaxis in the PEU according to the criteria of the European Academy of Allergy and Clinical Immunology (EAACI). Two allergists and a pediatrician reviewed the discharge summaries codified according to the International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) as urticaria, acute urticaria, angioedema, angioneurotic edema, unspecified allergy, and anaphylactic shock. Patients were divided into two groups according to the date of implantation of the protocol (2008): group A (2006-2007; the period before the introduction of the protocol) and group B (2008-2009; after the introduction of the protocol). We evaluated the incidence of anaphylaxis, epinephrine administration, prescription of self-injecting epinephrine (SIE), other drugs administered, the percentage of admissions and length of stay in the pediatric emergency observation area (PEOA), referrals to the allergy department, and the safety of epinephrine use.

RESULTS

During the 4 years of the study, 133,591 children were attended in the PEU, 1673 discharge summaries were reviewed, and 64 cases of anaphylaxis were identified. The incidence of anaphylaxis was 4.8 per 10,000 cases/year. After the introduction of the protocol, significant increases were observed in epinephrine administration (27% in group A and 57.6% in group B) (p = 0.012), in prescription of SIE (6.7% in group A and 54.5% in group B) (p = 0.005) and in the number of admissions to the PEOA (p = 0.003) and their duration (p = 0.005). Reductions were observed in the use of corticosteroid monotherapy (29% in group A, 3% in group B) (p = 0.005), and in patients discharged without follow-up instructions (69% in group A, 22% in group B) (p = 0.001). Thirty-three epinephrine doses were administered. Precordial palpitations were observed in one patient.

CONCLUSION

The application of the anaphylaxis protocol substantially improved the physicians' skills to manage this emergency in the PEU. Epinephrine administration showed no significant adverse effects.

A population-based epidemiologic study of emergency department visits for anaphylaxis in Florida

BACKGROUND

Previous population-based analyses of emergency department (ED) visits for anaphylaxis have been limited to small populations in limited geographic areas and focused on children or have included patients who had allergic conditions other than anaphylaxis.

OBJECTIVE

We sought to describe the epidemiology and risk factors among patients with anaphylaxis presenting to Florida EDs.

METHODS

Two thousand seven hundred fifty-one patients with anaphylaxis were identified for 2005-2006 within ED records by using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), and a validated ICD-9-CM-based algorithm. Age- and sex-specific rates were calculated. Regression analyses were used to determine relative risks for anaphylaxis caused by various triggers (food, venom, and medication) and risk factors (age, sex, race, and ethnicity).

RESULTS

The highest observed rates were among the youngest male subjects (8.2/100,000 Floridians aged 0-4 years) and among adult female subjects (15-54 years) grouped in 10-year age categories (9.9-10.9/100,000 Floridians). Male and black subjects were 20% and 25%, respectively, more likely to have a food trigger than female and white subjects. White, male, and older subjects were more likely to have an anaphylaxis-related ED visit caused by insect stings. Venom-induced anaphylaxis was more likely in August through October. Children were less likely than those older than 70 years (referent) to have medication-induced anaphylaxis (P < .03).

CONCLUSION

This is the only ED-based population study in a US lower-latitude state. The overall rate is considerably lower than other US ED-based population studies. The rates of anaphylaxis by age group differed by sex. Male and black subjects were more likely to have a food trigger.

Current understanding of Kounis syndrome

Inflammatory mediators, adhesion molecules of neutrophils and monocytes, have been shown to be increased in the plasma of patients presenting with acute coronary syndromes. Anaphylaxis is a systemic, immediate hypersensitivity reaction caused by rapid IgE-mediated release of mediators from mast cells and basophils. Kounis syndrome is the coincidental occurrence of these two distinct conditions accompanied by clinical and laboratory findings of angina pectoris caused by inflammatory mediators released during an allergic insult. Allergic angina can progress to acute myocardial infarction, which is termed 'allergic myocardial infarction'. There are several causes reported to be capable of inducing Kounis syndrome. These include a number of conditions, several drugs, foods and insect stings, among others. In this article, the clinical aspects, diagnosis, pathogenesis, incidence and epidemiology, related conditions and therapeutic management of this important syndrome are discussed.

Perspectives on anaphylaxis epidemiology in the United States with new data and analyses

Anaphylaxis incidence rates and time trends in the United States have been reported using different data sources and selection methods. Larger studies using diagnostic coding have inherent limitations in sensitivity and specificity. In contrast, smaller studies using chart reviews, including reports from single institutions, have better case characterization but suffer from reduced external validity due to their restricted nature. Increasing anaphylaxis hospitalization rates since the 1990s have been reported abroad. However, we report no significant overall increase in the United States. There have been several reports of increasing anaphylaxis rates in northern populations in the United States, especially in younger people, lending support to the suggestion that higher anaphylaxis rates occur at higher latitudes. We analyzed anaphylaxis hospitalization rates in comparably sized northern (New York) and southern (Florida) states and found significant time trend differences based on age. This suggests that the relationship of latitude to anaphylaxis incidence is complex.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

Predictors of hospital admission for food-related allergic reactions that present to the emergency department

BACKGROUND

guidelines do not provide specific hospitalization criteria for patients presenting to the emergency department (ED) with food-related allergic reactions.

OBJECTIVE

to determine predictors of hospital admission for ED patients with food-related allergic reactions.

METHODS

we performed a medical record review at 3 academic centers of patients presenting to the ED for food-related allergic reactions (International Classification of Diseases, Ninth Revision, Clinical Modification codes 693.1, 995.0, 995.1, 995.3, 995.7, 995.60-995.69, 558.3, 692.5, and 708.X) between January 1, 2001, and December 31, 2006. We focused on patient demographics, medical history, food triggers, clinical presentation, pre-ED and ED management with a specific focus on epinephrine treatment, and disposition. Predictors of hospital admission were determined using multivariable logistic regression.

RESULTS

through random sampling and appropriate weighting, the 1,112 cases reviewed represented a study cohort of 2,583 patients. Most patients (80%) were discharged from the ED. The age and sex of patients admitted to the hospital and those discharged were similar. Multivariable analysis identified 3 factors associated with a higher likelihood of hospital admission: meeting the criteria for food-related anaphylaxis (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.23-4.33), pre-ED epinephrine treatment (OR, 6.65; 95% CI, 3.04-14.57), and epinephrine treatment within 1 hour of ED triage (OR, 3.78; 95% CI, 1.68-8.50). Patients with food-related allergic reactions triggered by shellfish were less likely to be admitted to the hospital (OR, 0.23; 95% CI, 0.08-0.68).

CONCLUSIONS

most patients presenting to the ED with food-related allergic reactions are discharged. Several patient factors were independently associated with hospital admission in ED patients with food-related allergic reactions.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

North-south differences in US emergency department visits for acute allergic reactions

BACKGROUND

In a previous study, latitude was positively associated with EpiPen prescription rates.

OBJECTIVE

To determine whether a similar geographic difference exists for emergency department (ED) visits for acute allergic reactions (including anaphylaxis).

METHODS

We combined National Hospital Ambulatory Medical Care Survey data for ED visits to noninstitutional hospitals from 1993 to 2005. Acute allergic reactions were identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes 995.0, 995.60-995.69, 995.1, 995.2, 995.3, 989.5, and 693.1, and visit rates were compared across standardized geographic divisions.

RESULTS

Between 1993 and 2005, there were 17.3 million ED visits for acute allergic reactions, representing 1.3% (95% confidence interval [CI], 1.2%-1.3%) of all ED visits. Per 1000 population, the Northeast had 5.5 visits (95% CI, 4.7-6.2 visits) and the South had 4.9 visits (95% CI, 4.3-5.6 visits). In a multivariable model, the Northeast had a higher odds ratio (OR) than the South (1.13; 95% CI, 1.01-1.27; P = .04). The association was stronger when restricting the analysis to visits for food-related allergic reactions (OR, 1.33; 95% CI, 1.14-1.56; P < .001).

CONCLUSIONS

The ED visit rates for acute allergic reactions are higher in northeastern vs southern regions. These observational data are consistent with the hypothesis that vitamin D may play an etiologic role in anaphylaxis, especially food-induced anaphylaxis.

Algorithm for the diagnosis of anaphylaxis and its validation using population-based data on emergency department visits for anaphylaxis in Florida

BACKGROUND

Epidemiologic studies of anaphylaxis have been limited by significant underdiagnosis.

OBJECTIVE

The purpose of this study was to develop and validate a method for capturing previously unidentified anaphylaxis cases by using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) based datasets.

METHODS

Florida emergency department data for the years 2005 and 2006 from the Florida Agency for Health Care Administration were used. Patients with anaphylaxis were identified by using ICD-9-CM codes specifically indicating anaphylaxis or an ICD-9-CM algorithm based on the definition of anaphylaxis proposed at the 2005 National Institute of Allergy and Infectious Disease and the Food Allergy and Anaphylaxis Network symposium. Cases ascertained with the algorithm were compared with the traditional case-ascertainment method. Comparisons included demographic and clinical risk factors, proportion of monthly visits, and age/sex-specific rates. Cases ascertained with anaphylaxis ICD-9-CM codes were excluded from those ascertained with the algorithm.

RESULTS

One thousand one hundred forty-nine patients were identified by using anaphylaxis ICD-9-CM codes, and 1,602 patients were identified with the algorithm. The clinical risk factors and demographics of cases were consistent between the 2 methods. However, the algorithm was more likely to identify older subjects (P < .0001), those with hypertension or heart disease (P < .0001), and subjects with venom-induced anaphylaxis (P < .0001).

CONCLUSION

This study introduces and validates an ICD-9-CM-based diagnostic algorithm for the diagnosis of anaphylaxis to capture subjects missed by using the ICD-9-CM anaphylaxis codes. Fifty-eight percent of anaphylaxis cases would be missed without the use of the algorithm, including 88% of venom-induced cases.

Anaphylaxis epidemiology in patients with and patients without asthma: a United Kingdom database review

BACKGROUND

There are currently limited data regarding the epidemiology of anaphylaxis.

OBJECTIVE

To estimate the incidence of anaphylaxis from all causes, to explore the variety of diagnoses that may predispose to an anaphylactic episode, and to estimate the rate of recurrence of anaphylaxis in patients with no asthma, nonsevere asthma, and severe asthma.

METHODS

The Health Improvement Network database provided data on individuals 10 to 79 years old who had been enrolled for at least 1 year with a general practitioner in the United Kingdom and had at least 1 health contact in the year before entering the study.

RESULTS

Anaphylaxis incidence rates (per 100,000 person-years) were 21.28 (95% CI, 17.64-25.44) and 50.45 (95% CI, 44.67-56.76) in the no asthma and overall asthma cohorts, respectively. Risk of anaphylaxis was greater in the nonsevere asthma (relative risk, 2.07; 95% CI, 1.65-2.60) and severe asthma (relative risk, 3.29; 95% CI, 2.47-3.47) subgroups compared with the no asthma cohort. The incidence rate of anaphylaxis was higher in women than men (22.65 vs 19.56 per 100,000 person-years). Within the overall asthma population, patients at significantly increased risk of anaphylaxis included those with allergic rhinitis or atopic dermatitis, and current users of antihistamines, oral steroids, or antibiotics (compared with nonusers). Drug and food allergies were the most common known causes of anaphylaxis.

CONCLUSION

Patients with asthma have a greater risk of anaphylaxis than those without asthma, and the risk is greater in severe than nonsevere asthma. Women are at higher risk of anaphylaxis than men, especially those with severe asthma.

Multicenter study of repeat epinephrine treatments for food-related anaphylaxis

OBJECTIVE

We sought to establish the frequency of receiving >1 dose of epinephrine in children who present to the emergency department (ED) with food-related anaphylaxis.

PATIENTS AND METHODS

We performed a medical chart review at Boston hospitals of all children presenting to the ED for food-related acute allergic reactions between January 1, 2001, and December 31, 2006. We focused on causative foods, clinical presentations, and emergency treatments.

RESULTS

Through random sampling and appropriate weighting, the 605 reviewed cases represented a study cohort of 1255 patients. These patients had a median age of 5.8 years (95% confidence interval [CI]: 5.3-6.3), and the cohort was 62% male. A variety of foods provoked the allergic reactions, including peanuts (23%), tree nuts (18%), and milk (15%). Approximately half (52% [95% CI: 48-57]) of the children met diagnostic criteria for food-related anaphylaxis. Among those with anaphylaxis, 31% received 1 dose and 3% received >1 dose of epinephrine before their arrival to the ED. In the ED, patients with anaphylaxis received antihistamines (59%), corticosteroids (57%), epinephrine (20%). Over the course of their reaction, 44% of patients with food-related anaphylaxis received epinephrine, and among this subset of patients, 12% (95% CI: 9-14) received >1 dose. Risk factors for repeat epinephrine use included older age and transfer from an outside hospital. Most patients (88%) were discharged from the hospital. On ED discharge, 43% were prescribed self-injectable epinephrine, and only 22% were referred to an allergist.

CONCLUSIONS

Among children with food-related anaphylaxis who received epinephrine, 12% received a second dose. Results of this study support the recommendation that children at risk for food-related anaphylaxis carry 2 doses of epinephrine.

Suboptimal management of acute food-allergic reactions by patients, emergency departments and general practitioners

Suboptimal food allergy management by patients and doctors.

Visual representation of National Institute of Allergy and Infectious Disease and Food Allergy and Anaphylaxis Network criteria for anaphylaxis

We present a user-friendly visual representation of The National Institute of Allergy and Infectious Disease and the Food Allergy and Anaphylaxis Network criteria so as to enhance recognition of anaphylaxis and active teaching and learning.

Adrenaline for the treatment of anaphylaxis: cochrane systematic review

BACKGROUND

Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. Adrenaline is recommended as the initial treatment of choice for anaphylaxis.

OBJECTIVES

To assess the benefits and harms of adrenaline in the treatment of anaphylaxis.

METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to March 2007), EMBASE (1966 to March 2007), CINAHL (1982 to March 2007), BIOSIS (to March 2007), ISI Web of Knowledge (to March 2007) and LILACS (to March 2007). We also searched websites listing ongoing trials: http://www.clinicaltrials.gov/, http://www.controlledtrials.com and http://www.actr.org.au/ and contacted pharmaceutical companies and international experts in anaphylaxis in an attempt to locate unpublished material. Randomized and quasi-randomized controlled trials comparing adrenaline with no intervention, placebo or other adrenergic agonists were eligible for inclusion. Two authors independently assessed articles for inclusion.

RESULTS

We found no studies that satisfied the inclusion criteria.

CONCLUSIONS

On the basis of this review, we are unable to make any new recommendations on the use of adrenaline for the treatment of anaphylaxis. In the absence of appropriate trials, we recommend, albeit on the basis of less than optimal evidence, that adrenaline administration by intramuscular injection should still be regarded as first-line treatment for the management of anaphylaxis.

Prescriptions for self-injectable epinephrine and follow-up referral in emergency department patients presenting with anaphylaxis

BACKGROUND

Anaphylaxis guidelines recommend that patients with a history of anaphylactic reaction should carry self-injectable epinephrine and should be referred to an allergist.

OBJECTIVE

To evaluate how frequently patients dismissed from the emergency department after treatment for anaphylaxis received a prescription for self-injectable epinephrine or allergist referral.

METHODS

A retrospective medical record review identified patients with anaphylaxis in a community-based study from 1990 through 2000. Records of patients with Hospital Adaptation of the International Classification of Diseases, Second Edition or International Classification of Diseases, Ninth Revision codes representing anaphylaxis were reviewed, and a random sample of patients with associated diagnoses was also reviewed. Patients who met the criteria for diagnosis of anaphylaxis were included in the study.

RESULTS

Among 208 patients identified with anaphylaxis, 134 (64.4%) were seen in the emergency department and discharged home. On dismissal, 49 patients (36.6%; 95% confidence interval [CI], 28.4%-44.7%) were prescribed self-injectable epinephrine, and 42 patients (31.3%; 95% CI, 23.5%-39.2%) were referred to an allergist. Treatment with epinephrine in the emergency department (odds ratio, 3.6; 95% CI, 1.6-7.9; P = .001) and insect sting as the inciting allergen (odds ratio, 4.0; 95% CI, 1.6-10.5; P = .004) were significantly associated with receiving a prescription for self-injectable epinephrine. Patient age younger than 18 years was the only factor associated with referral to an allergist (P = .007).

CONCLUSIONS

Most patients dismissed after treatment for anaphylaxis did not receive a self-injectable epinephrine prescription or allergist referral. Emergency physicians may be missing an important opportunity to ensure prompt treatment of future anaphylactic reactions and specialized follow-up care.