Anaphylaxis: A 2023 practice parameter update

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

Positive Predictive Values of Anaphylaxis Diagnosis in Claims Data: A Multi-Institutional Study in Taiwan

Real-world data sources can facilitate essential understanding of the epidemiological features of anaphylaxis. However, the accuracy of case-identifying definitions based on diagnosis codes for anaphylaxis in healthcare databases remains understudied. We conducted a cross-sectional study analyzing claims data from the largest multi-institutional healthcare system in Taiwan during 2017-2021. We included patients with incident anaphylaxis identified by either ICD-10-CM codes for anaphylaxis (Group 1) or ICD-10-CM codes for severe allergic or drug adverse events and additional modifier codes for acute allergy events (Group 2). We randomly selected 20% of the cases to determine the positive predictive value (PPV) of anaphylaxis case-identifying definitions in Groups 1 and 2 after review of electronic medical records by two physicians. From the original cohort (n = 2,176), we randomly selected 433 patients with either a diagnosis of anaphylaxis (Group 1), or a diagnosis of severe allergic and drug adverse events with additional modifier codes for acute allergy events (Group 2). In Group 1, we judged 135 / 170 patients as true anaphylaxis cases, giving a PPV of 79.4% (95% CI: 73.3-85.5). In Group 2, we judged 47 / 263 patients as true anaphylaxis cases, giving a PPV of 17.9% (95% CI: 13.3-22.5). In conclusion, acceptable PPVs were observed when anaphylaxis cases were identified by ICD-10-CM codes for anaphylaxis, but not by ICD-10-CM codes for severe allergic or drug adverse event with additional modifier codes for acute allergy events. Our multi-institutional findings could serve as a fundamental reference for further studies of anaphylaxis based on real-world healthcare databases.

Spread of stinging ants to oceanic islands, and the need to raise awareness of prevention and treatment of ant stings

OBJECTIVE

Venomous invasive ants are rapidly dispersing throughout oceanic islands. Medics unfamiliar with envenomation or venom-induced anaphylaxis may be unprepared for the range of possible reactions and corresponding treatments. We detail the suboptimal treatment of a patient suffering anaphylaxis from an ant sting on a remote island and describe what treatment should have been provided.

METHODS

The patient experienced stings on his feet from an ant later identified as tropical fire ant, Solenopsis geminata. Clinical examination revealed throat swelling without obstruction of the airway or pharynx.

RESULTS

The patient was provided the following suboptimal treatment: intravenously-administered antihistamine and saline perfusion. Injected epinephrine should be the standard first line of treatment for anaphylaxis, even when not all symptoms are present.

CONCLUSION

A rise in invasive hymenopteran stings on oceanic islands is inevitable, and proactively improving public awareness and medical training could save lives.

Trends and determinants of epinephrine prescriptions: a proxy of anaphylaxis epidemiology?

PURPOSE OF REVIEW

Epinephrine autoinjectors (EAIs) are recommended to all patients previously experiencing anaphylaxis reaction in order to prevent further reactions and fatalities. Under that perspective, EAI prescription could be considered as a proxy of anaphylaxis epidemiology. Nevertheless EAI prescription rates are still unacceptably low.

RECENT FINDINGS

The review focuses on potential determinants, in addition to clinical indications, which might impact EAI prescription rates by exploring the scientific literature published within the past 18 months, wherever available. Although some controversial results, age, sex, ethnicity, geographical setting and socioeconomic conditions might influence both physician prescription behaviour and EAIs' accessibility from the patient's side, which hampers the accuracy of EAI prescription as a proxy of anaphylaxis. Low EAI prescription and refill rates have been recorded even in the absence of significant socioeconomic barriers, suggesting that economical limitations only partially account for the issue, and cultural restrictions have also to be considered and addressed.

SUMMARY

In addition to providing the same opportunities in terms of EAI availability in all countries worldwide, implementing the resources for anaphylaxis management in terms of practical knowledge, education, and allergy specialist networks is an urgent need, even in the absence of socioeconomic barriers.

Anaphylaxis: Epidemiology and Differential Diagnosis

Anaphylaxis-related emergency department (ED) visits and hospitalizations are increasing. Triggers for anaphylaxis include food, medications, and stinging insects. Idiopathic anaphylaxis accounts for 30% to 60% of cases of anaphylaxis in adults and up to 10% of cases in children with novel allergens such as galactose-α-1,3 galactose reclassifying these cases. Recent practice guidelines have recommended against the routine use of systemic corticosteroids and antihistamines for the prevention of biphasic reactions and recommend an extended observation, up to 6 hours, for those with risk factors for biphasic anaphylaxis and those with lack of access to epinephrine and to emergency medical services.

Food-induced anaphylaxis morbidity: Emergency department and hospitalization data support preventive strategies

BACKGROUND

Anaphylaxis is a recognized public health issue. There is no doubt that food-induced anaphylaxis (FIA) has tremendous impact on the quality of life of patients and their families and increases direct and indirect costs. FIA is associated with increasing rates of emergency department admissions and hospitalizations and implies the risk of death. Morbidity epidemiological data are a key to tailor public health actions to this non-communicable disease. The aim of this article was to review published morbidity epidemiological data relating to FIA and potential risk factors, in order to provide evidence-based recommendations to reduce the risk of severe adverse outcomes.

METHODS

We identified published studies available in PUBMED/MEDLINE (1966-2020), EMBASE (1980-2020) and CINAHL (1982-2020). The systematic review was carried out using MeSH terms related to FIA ED admissions and hospitalizations.

RESULTS

A total of 25 articles were selected, 80% published in the last 5 years. After critical analysis of methodological and clinical characteristics reported in the data selected, we were able to propose preventive strategies.

CONCLUSION

Anaphylaxis is a recognized public health issue. FIA is associated with increasing rates of ED admissions and hospitalizations and imply in risk of death. More than reviewing and critically interpreting the key patterns related to FIA morbidity published data, we proposed strategies in order to promote quality care of patients suffering from FIA. Our World Health Organization Collaborative Center is deeply involved in this process, and we believe that the proposed strategies will inform future healthcare policies on anaphylaxis. The long-term objective would be to improve clinical care and quality of life of patients and their families, and develop risk-stratified, cost-effective preventive measures.

Biologicals for the prevention of anaphylaxis

PURPOSE OF REVIEW

To review the use of biological agents (BA) in the treatment of anaphylaxis in the view of the new knowledge in the field to support the quality of care and prevention.

RECENT FINDINGS

Some BA, as a single medication or as combined therapy to food or venom immunotherapy, are effectively able to reduce most of the severe anaphylactic reactions.

SUMMARY

Anaphylaxis is a recognized clinical emergency, which requires prompt identification and treatment. Several biologic therapies and new devices are emerging as a potential preventive treatment for anaphylaxis. However, adrenaline (epinephrine) is still the first-line treatment for any type of anaphylaxis. Biological drugs, such as omalizumab, whereas not US Food and Drug Administration (FDA) nor European Medicines Agency (EMA) approved for anaphylaxis, have been used as therapeutic adjuvants in the preventive treatment of anaphylaxis, but cost-effectiveness should be considered individually.

Emergency medicine updates: Anaphylaxis

INTRODUCTION

Anaphylaxis is a potentially deadly condition that requires emergent therapy. While frequently treated in the emergency department (ED), recent evidence updates may improve the diagnosis and management of this condition.

OBJECTIVE

This paper evaluates key evidence-based updates concerning the diagnosis and management of anaphylaxis for the emergency clinician.

DISCUSSION

The presentation of anaphylaxis can vary. Current diagnostic criteria can be helpful when evaluating patients for anaphylaxis, though multiple criteria exist. While the most common causes of anaphylaxis include medications, insect venom, and foods, recent literature has identified an IgE antibody response to mammalian galactose alpha-1,3-galactose, known as alpha-gal anaphylaxis. Epinephrine is the first-line therapy and is given in doses of 0.01 mg/kg (up to 0.5 mg in adults) intramuscularly (IM) in the anterolateral thigh. Intravenous (IV) epinephrine administration is recommended in patients refractory to IM epinephrine and IV fluids, or those with cardiovascular collapse. Antihistamines and glucocorticoids should not delay administration of epinephrine and do not demonstrate a significant reduction in risk of biphasic reactions. Biphasic reactions may affect 1-7% of patients with anaphylaxis. Risk factors for biphasic reaction include severe initial presentation and repeated doses of epinephrine. Disposition of patients with anaphylaxis requires consideration of several factors.

CONCLUSIONS

Emergency clinicians must be aware of current updates in the evaluation and management of this disease.

Effects of Glucocorticoids on Hospitalized Children With Anaphylaxis

BACKGROUND

The benefits of glucocorticoid treatment and recent trends of adjunctive treatments during episodes of anaphylaxis remain unclear.

OBJECTIVES

The aims of this study were to investigate the recent practice patterns and compare the effects of glucocorticoid for children hospitalized with anaphylaxis.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database, we compared the length of hospital stay, risk of 10-day readmission, and total hospitalization cost between the steroid and nonsteroid groups. We also evaluated recent trends of adjunctive treatments for anaphylaxis.

RESULTS

From 2010 to 2014, the proportions of H1-receptor antagonist use increased from 65.1% to 71.8% (Ptrend = 0.02). The proportions of H2-receptor antagonist use showed an upward trend, ranging from 12.8% to 16.7% (Ptrend = 0.01). No significant change in glucocorticoid use was observed (from 86.7% to 82.6%; Ptrend = 0.08). Stabilized inverse probability-weighting analyses showed that the total length of hospital stay was 0.39 days longer in the steroid group than in the nonsteroid group (95% confidence interval, 0.29-0.49 days). Total hospitalization cost was greater in the steroid group than in the nonsteroid group (difference, ¥3896; 95% confidence interval, ¥2464-¥5562). No significant difference in risk of 10-day readmission was observed between the groups. Instrumental variable analyses showed similar results to stabilized inverse probability-weighting analyses.

CONCLUSIONS

We observed increasing trends of H1- and H2-receptor antagonist use. Length of hospital stay and total hospitalization cost were greater in the steroid group than in the nonsteroid group, whereas readmission risks were similar between the 2 groups.

Epidemiology of anaphylaxis

PURPOSE OF REVIEW

To understand the current global epidemiological data of anaphylaxis and identify potential strategies to improve patients' care and prevention.

RECENT FINDINGS

Anaphylaxis mortality and morbidity statistics (MMS) may gain new perspectives with the implementation of the International Classification of Diseases (ICD)-11 in the forthcoming years. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk, and support decision-making to facilitate healthcare planning and implementation of public health measures to prevent anaphylaxis.

SUMMARY

Anaphylaxis is a complex noncommunicable diseases with adverse impact on health-related quality of life of patients and their carriers and a significant proportion of deaths may be preventable. It requires an integrated holistic plan to improve quality of healthcare and gathering accurate and comparable epidemiological data is key. Morbidity related to anaphylaxis seems to be increasing worldwide whereas mortality of anaphylaxis appears to be low and stable, but this still has great challenges in capturing quality anaphylaxis MMS. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk. As knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to anaphylaxis in the ICD-11 will allow the collection of more accurate epidemiological data to support quality management of patients, and better facilitate healthcare planning to implement public health measures to prevent and reduce the morbidity and mortality attributable to these conditions.

Consensus on DEfinition of Food Allergy SEverity (DEFASE) an integrated mixed methods systematic review

BACKGROUND AND AIMS

The term "Food Allergy" refers to a complex global health problem with a wide spectrum of severity. However, a uniform definition of severe food allergy is currently missing. This systematic review is the preliminary step towards a state-of-the-art synopsis of the current evidence relating to the severity of IgE-mediated food allergy; it will inform attempts to develop a consensus to define food allergy severity by clinicians and other stakeholders.

METHODS

We undertook a mixed-methods systematic review, which involved searching 11 international biomedical databases for published studies from inception to 31 December 2019. Studies were independently screened against pre-defined eligibility criteria and critically appraised by established instruments. The substantial heterogeneity of included studies precluded meta-analyses and, therefore, narrative synthesis of quantitative and qualitative data was performed.

RESULTS

We found 23 studies providing eligible primary data on symptom-specific severity of food allergic reactions, and 31 previously published symptom-severity scoring systems referred to food allergic reactions. There were seven studies which assessed quality-of-life measures in patients (and family members) with different food allergy severity and two studies that investigated the economic burden of food allergy severity. Overall, the quality and the global rating of all included studies were judged as being moderate.

CONCLUSIONS

There is heterogeneity among severity scoring systems used and even outcomes considered in the context of severity of food allergy. No score has been validated. Our results will be used to inform the development of an international consensus to define the severity of food allergy.

SYSTEMATIC REVIEW REGISTRATION

A protocol was prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO) database with the registration number CRD42020183103 (https://www.crd.york.ac.uk/prospero/#recordDetails).

Comorbidities and Cofactors of Anaphylaxis in Patients with Moderate to Severe Anaphylaxis. Analysis of Data from the Anaphylaxis Registry for West Pomerania Province, Poland

Anaphylaxis is a severe, potentially life-threatening systemic hypersensitivity reaction that is still rarely diagnosed. For safety reasons, patients should visit an allergologist to identify potential causes and cofactors of this reaction. This paper presents the analysis of data from the Anaphylaxis Registry gathered over ten years at the Allergy Clinic, Pomeranian Medical University (PMU). A questionnaire-based survey was used for patients visiting the Allergy Clinic to identify potential augmentation factors/comorbidities and/or cofactors of anaphylaxis in patients with a history of moderate to severe anaphylaxis. The registry comprised patients with grade II or higher anaphylaxis. The gathered data concerned chronic comorbidities (cardiovascular diseases, respiratory diseases, and others), recurrence of anaphylaxis, and potential cofactors in anaphylaxis. In the analyzed group, the incidence rate of anaphylaxis was the highest for women aged 19–60 years. Most common comorbidities in patients with moderate to severe anaphylaxis included: cardiovascular diseases, respiratory tract diseases, features of atopy, and thyroid diseases. More than 30% of drug-induced reactions were anaphylactic reactions due to the re-exposure to the same drug, which points to the need for educational initiatives in this area. The incidence rate of anaphylaxis induced by Hymenoptera stings was comparable in patients who had a previous generalized reaction and those who had good tolerance to the previous sting. It is important to take these cofactors into consideration when evaluating patients with anaphylaxis as they may play a role in future anaphylactic reactions.

A Proposal from the Montpellier World Health Organization Collaborating Centre for Better Management and Prevention of Anaphylaxis

Since the first description of anaphylaxis in 1902, its clinical importance as an emergency condition has been recognized worldwide. Anaphylaxis is a severe, potentially life-threatening systemic hypersensitivity reaction characterized by rapid onset and the potential to endanger life through respiratory or circulatory compromise. It is usually, although not always, associated with skin and mucosal changes. Although the academic/scientific communities have advocated to promote greater awareness and protocols for the management of anaphylaxis based on best evidence, there are few efforts documenting feedback as to the success of these efforts. In this article, we review the key unmet needs related to the diagnosis and management of anaphylaxis, and propose a public health initiative for prevention measures and a timetable action plan that intends to strengthen the collaboration among health professionals and especially primary care physicians dealing with anaphylaxis, which can encourage enhanced quality of care of patients with anaphylaxis. More than calling for a harmonized action for the best management of anaphylaxis to prevent undue morbidity and mortality, the Montpellier World Health Organization Collaborating Centre here proposes an action plan as a baseline for a global initiative against anaphylaxis. We strongly believe that these collaborative efforts are a strong public health and societal priority that is consistent with the overarching goals of providing optimal care of allergic patients and best practices of allergology.

World allergy organization anaphylaxis guidance 2020

Anaphylaxis is the most severe clinical presentation of acute systemic allergic reactions. The occurrence of anaphylaxis has increased in recent years, and subsequently, there is a need to continue disseminating knowledge on the diagnosis and management, so every healthcare professional is prepared to deal with such emergencies. The rationale of this updated position document is the need to keep guidance aligned with the current state of the art of knowledge in anaphylaxis management. The World Allergy Organization (WAO) anaphylaxis guidelines were published in 2011, and the current guidance adopts their major indications, incorporating some novel changes. Intramuscular epinephrine (adrenaline) continues to be the first-line treatment for anaphylaxis. Nevertheless, its use remains suboptimal. After an anaphylaxis occurrence, patients should be referred to a specialist to assess the potential cause and to be educated on prevention of recurrences and self-management. The limited availability of epinephrine auto-injectors remains a major problem in many countries, as well as their affordability for some patients.

Asthma and anaphylaxis

PURPOSE OF REVIEW

Both asthma and anaphylaxis are recognized noncommunicable hypersensitivity conditions, which should be correctly diagnosed and treated/controlled in order to decrease avoidable deaths. Nevertheless, their association is not completely clear. We here propose to review the current and new evidence-based data of asthma and anaphylaxis in the view of the new knowledge in the field that can support the quality practice and empower allergists and health professionals in treating symptoms and preventing death.

RECENT FINDINGS

Hypersensitivity life-threatening conditions, such as anaphylaxis and asthma can coexist, mimic or worse each other. Asthma itself is not a strong predictor of more severe anaphylaxis. However, poor asthma control associated with more severe anaphylaxis reactions in all ages. In children, asthma is associated with the severity and recurrences of anaphylactic reactions.

SUMMARY

Although recent data point for the association between asthma and anaphylaxis, we still do not have harmonized evidence to confirm if we are dealing with two independent comorbidities one worsening each other. However, as far as this review is covering two relevant public health problems in the field of allergy, it is mandatory put in place decisions supporting recommendations to better manage the affected patients and reduce the risk.General strategies should include regular notification of this association, optimization of the classification and coding for anaphylaxis and asthma (new ICD 11 allergy codes) in order to harmonize epidemiological stratified data, early diagnosis of asthma in childhood, regular investigation of asthma in cases of anaphylaxis and optimization of the asthma control and lung function for all patients with indication to provocation tests, desensitization or allergen immunotherapy regardless to the trigger. Implementation of these strategies will involve national and international support for ongoing efforts in relationship with networks of centres of excellence to provide personalized management for the most at-risk patients and prevent death.

Midazolam anaphylaxis during general anesthesia: A case report

RATIONALE

Midazolam is known as a safe drug and is widely used as a sedative and an anesthetic adjuvant. Therefore, there is a lack of awareness that midazolam can cause anaphylaxis. Midazolam anaphylaxis is rare, and only a few cases have been reported, but such a risk is always present. In this study, we report a case of midazolam anaphylaxis by an intravenous injection, in the prone position, during general anesthesia.

PATIENT CONCERNS

A 62-year-old woman was intravenously administered 1 mg midazolam during general anesthesia, and sudden severe hypotension, bronchospasm, decreased oxygen saturation, erythema, and diarrhea occurred.

DIAGNOSIS

Midazolam anaphylaxis was presumptively diagnosed by clinical symptoms and was confirmed by an intradermal test after 9 weeks.

INTERVENTIONS

The patient was treated with 100% oxygen, large volume of fluid, epinephrine, phenylephrine, ephedrine, dexamethasone and prednisolone, ranitidine, and flumazenil.

OUTCOMES

Severe hypotension and decreased oxygen saturation were resolved within 20 minutes of the onset of anaphylaxis, and the patient was discharged after 3 days without any sequelae.

LESSONS

Midazolam anaphylaxis is very rare, but it can happen always. Therefore, the possibility of anaphylaxis due to midazolam should be considered and always be prepared for treatment.

Changing the history of anaphylaxis mortality statistics through the World Health Organization's International Classification of Diseases-11

We review the history of the classification and coding changes for anaphylaxis and provide current and perspective information in the field. In 2012, an analysis of Brazilian data demonstrated undernotification of anaphylaxis-related deaths because of the difficulties of coding using the International Classification of Diseases, 10th Revision. This work triggered strategic international actions supported by the Joint Allergy Academies and the International Classification of Diseases World Health Organization (WHO) leadership to update the classification of allergic disorders for the International Classification of Diseases, 11th Revision (ICD-11), which resulted in construction of the pioneer "Allergic and hypersensitivity conditions" chapter. The usability of the new framework has been tested by evaluating the same data published in 2012 from the ICD-11 perspective. Coding accuracy was much improved, reaching 95% for definite anaphylaxis. As the results were provided to the WHO Mortality Reference Group, coding rules have been changed, allowing anaphylaxis to be recorded as an underlying cause of death in official mortality statistics. The mandatory use of ICD-11 from January 2022 for documenting cause of death could have 2 immediate consequences: (1) the reported number of anaphylaxis-related deaths might increase because of more appropriate coding and (2) the cross-sectional and longitudinal mortality data generated might ultimately lead to a better understanding of anaphylaxis epidemiology and improved health policies directed at reducing anaphylaxis-related mortality.

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.

Acute Severe Anaphylaxis in Nepali Patients with Neurotoxic Snakebite Envenoming Treated with the VINS Polyvalent Antivenom

Diagnosing and treating acute severe and recurrent antivenom-related anaphylaxis (ARA) is challenging and reported experience is limited. Herein, we describe our experience of severe ARA in patients with neurotoxic snakebite envenoming in Nepal. Patients were enrolled in a randomised, double-blind trial of high vs. low dose antivenom, given by intravenous (IV) push, followed by infusion. Training in ARA management emphasised stopping antivenom and giving intramuscular (IM) adrenaline, IV hydrocortisone, and IV chlorphenamine at the first sign/s of ARA. Later, IV adrenaline infusion (IVAI) was introduced for patients with antecedent ARA requiring additional antivenom infusions. Preantivenom subcutaneous adrenaline (SCAd) was introduced in the second study year (2012). Of 155 envenomed patients who received ≥ 1 antivenom dose, 13 (8.4%), three children (aged 5−11 years) and 10 adults (18−52 years), developed clinical features consistent with severe ARA, including six with overlapping signs of severe envenoming. Four and nine patients received low and high dose antivenom, respectively, and six had received SCAd. Principal signs of severe ARA were dyspnoea alone (n=5 patients), dyspnoea with wheezing (n=3), hypotension (n=3), shock (n=3), restlessness (n=3), respiratory/cardiorespiratory arrest (n=7), and early (n=1) and late laryngeal oedema (n=1); rash was associated with severe ARA in 10 patients. Four patients were given IVAI. Of the 8 (5.1%) deaths, three occurred in transit to hospital. Severe ARA was common and recurrent and had overlapping signs with severe neurotoxic envenoming. Optimising the management of ARA at different healthy system levels needs more research. This trial is registered with NCT01284855.

Medication-related anaphylaxis treated in hospital: Agents implicated, patient outcomes, and management lessons

PURPOSE

On background of increasing medication-related anaphylaxis rates in Australia, our aim was to determine epidemiology, outcomes, adverse drug reaction (ADR) reporting rates, and accuracy of coding in patients treated for nonantimicrobial medication-related anaphylaxis in our hospital network.

METHODS

From January 2010 to December 2015 patients treated in our hospital network for medication-related anaphylaxis were identified using International Classification of Diseases, 10th Edition diagnosis code T88.6. Cases were also extracted from the hospital ADR database. Medical records were reviewed to ensure consistent diagnosis and to extract clinical, documentation, and outcome data.

RESULTS

Of 1110 patients coded as T88.6, 177 (15.9%) met the medication-related anaphylaxis definition. Eighty (40.8%) had anaphylaxis due to nonantimicrobial agents. Thirteen of these (16.3%) had a previous reaction to the same medication/group. In 51 (63.8%) patients, anaphylaxis occurred during inpatient stay, with 31 reactions occurring during surgery. Eighty-five medications were implicated, most commonly neuromuscular blocking agents (31, 36.5%) and nonsteroidal anti-inflammatory drugs. No trends were noted over the 6-year period, and there was no anaphylaxis-related mortality. Fifty-three (66.3%) patients were assessed in allergy clinics. One in 10 cases did not have the reaction documented in the discharge summary. Adverse drug reaction reports were received for 38 patients (47.5%).

CONCLUSIONS

Although acute patient outcomes were excellent, gaps in practice were noted regarding ADR coding accuracy and reporting rates. One in 6 patients had a prior hypersensitivity reaction to a similar medication, so we recommend accurate documentation, ADR review with allergy follow-up, and patient held information to decrease re-exposure risk.

Critical view of anaphylaxis epidemiology: open questions and new perspectives

In contrast to the majority of allergic or hypersensitivity conditions, worldwide anaphylaxis epidemiological data remain sparse with low accuracy, which hampers comparable morbidity statistics. Data can differ widely depending on a number of variables. In the current document we reviewed the forms on which anaphylaxis has been defined and classified; and how it can affect epidemiological data. With regards to the methods used to capture morbidity statistics, we observed the impact of the anaphylaxis coding utilizing the World Health Organization's International Classification of Diseases. As an outcome and depending on the anaphylaxis definition, we extracted the cumulative incidence, which may not reflect the real number of new cases. The new ICD-11 anaphylaxis subsection developments and critical view of morbidity statistics data are discussed in order to reach new perspectives on anaphylaxis epidemiology.

Paediatric food-induced anaphylaxis hospital presentations in New Zealand

AIM

Globally, rates of paediatric food-induced anaphylaxis (FIA) are increasing. Little data is available regarding the epidemiology of FIA among New Zealand (NZ) children. This study investigated the incidence of paediatric (0-14 years) FIA hospital presentations in NZ over a 10-year period.

METHODS

Ministry of Health public hospital discharge data from 2006 to 2015 were analysed using FIA-related International Classification of Diseases codes (T78.0 - anaphylactic shock due to adverse food reaction and T78.2 - anaphylactic shock unspecified and free text qualifier) to identify acute hospital presentations.

RESULTS

The overall annualised FIA hospital presentation rate was 16.2 per 100 000 children. Subgroup analysis indicated a significantly higher rate in males (19.1/100 000) than in females (13.1/100 000), and among children aged less than 2 years of age (50.5/100 000) compared with older children. Rates among Asian and Pacific children were higher than Māori and NZ European children. In 67.7% of cases, a single specific allergen was suggested by the information provided; among these cases, nuts (48%), specifically peanuts (26%), were the most commonly reported allergen, followed by cow's milk (21%). Time trend analysis showed a 2.8-fold increase in the overall annualised rate for the 10-year period.

CONCLUSION

These findings are consistent with other international studies indicating increasing rates of FIA in children. These data will provide information for a review of NZ paediatric allergy services to ensure current international standards with regard to the equitable delivery of timely, appropriate and accessible care are being met. Reasons for differences by gender, age and ethnicity require further investigation.

Are Registration of Disease Codes for Adult Anaphylaxis Accurate in the Emergency Department?

Purpose

There has been active research on anaphylaxis, but many study subjects are limited to patients registered with anaphylaxis codes. However, anaphylaxis codes tend to be underused. The aim of this study was to investigate the accuracy of anaphylaxis code registration and the clinical characteristics of accurate and inaccurate anaphylaxis registration in anaphylactic patients.

Methods

This retrospective study evaluated the medical records of adult patients who visited the university hospital emergency department between 2012 and 2016. The study subjects were divided into the groups with accurate and inaccurate anaphylaxis codes registered under anaphylaxis and other allergy-related codes and symptom-related codes, respectively.

Results

Among 211,486 patients, 618 (0.29%) had anaphylaxis. Of these, 161 and 457 were assigned to the accurate and inaccurate coding groups, respectively. The average age, transportation to the emergency department, past anaphylaxis history, cancer history, and the cause of anaphylaxis differed between the 2 groups. Cutaneous symptom manifested more frequently in the inaccurate coding group, while cardiovascular and neurologic symptoms were more frequently observed in the accurate group. Severe symptoms and non-alert consciousness were more common in the accurate group. Oxygen supply, intubation, and epinephrine were more commonly used as treatments for anaphylaxis in the accurate group. Anaphylactic patients with cardiovascular symptoms, severe symptoms, and epinephrine use were more likely to be accurately registered with anaphylaxis disease codes.

Conclusions

In case of anaphylaxis, more patients were registered inaccurately under other allergy-related codes and symptom-related codes rather than accurately under anaphylaxis disease codes. Cardiovascular symptoms, severe symptoms, and epinephrine treatment were factors associated with accurate registration with anaphylaxis disease codes in patients with anaphylaxis.

Epidemiology of severe anaphylaxis: can we use population-based data to understand anaphylaxis?

PURPOSE OF REVIEW

The observed increase in incidence of allergic disease in many regions over the past 3 decades has intensified interest in understanding the epidemiology of severe allergic reactions. We discuss the issues in collecting and interpreting these data and highlight current deficiencies in the current methods of data gathering.

RECENT FINDINGS

Anaphylaxis, as measured by hospital admission rates, is not uncommon and has increased in the United Kingdom, the United States, Canada, and Australia over the last 10-20 years. All large datasets are hampered by a large proportion of uncoded, 'unspecified' causes of anaphylaxis. Fatal anaphylaxis remains a rare event, but appears to be increasing for medication in Australia, Canada, and the United States. The rate of fatal food anaphylaxis is stable in the United Kingdom and the United States, but has increased in Australia. The age distribution for fatal food anaphylaxis is different to other causes, with data suggesting an age-related predisposition to fatal outcomes in teenagers and adults to the fourth decade of life.

SUMMARY

The increasing rates of food and medication allergy (the latter exacerbated by an ageing population) has significant implications for future fatality trends. An improved ability to accurately gather and analyse population-level anaphylaxis data in a harmonized fashion is required, so as to ultimately minimize risk and improve management.

Anaphylaxis

Anaphylaxis is an acute, systemic reaction mediated by immunoglobulin E hypersensitivity. Release of bioactive factors causes vasodilation and bronchiole constriction that can lead to hypotensive shock and asphyxiation. Differential diagnosis includes acute asthma, localized angioedema, syncope, and anxiety/panic attacks. Diagnostic tests lack specificity. Clinical diagnosis is based on demonstration of specific airway or cardiovascular compromise within proximity of allergen exposure. Treatment includes epinephrine, antihistamines, fluid resuscitation, and airway management. Prevention focuses on awareness/avoidance of triggers, implementation of personalized action plans, as well as immune modulation by desensitization in a closely controlled setting where available.

Adrenaline in anaphylaxis treatment and self-administration: experience from an inner city emergency department

BACKGROUND

Anaphylaxis is a life-threatening emergency of which reliable epidemiological data are lacking. This study aimed to analyze how quickly patients presenting with anaphylaxis were treated in emergency and whether treatment followed the European Academy of Allergy and Clinical Immunology (EAACI) guidelines.

METHODS

Patient data were collected between April 2009 and April 2013. Emergency doctors completed a questionnaire for adult patients presenting at the emergency department (ED) of the St. Pierre hospital in Brussels with anaphylaxis. Inclusion criteria were based on the Sampson criteria of anaphylaxis. Data were analyzed using a Microsoft Excel database.

RESULTS

About 0.04% (100/230878) of all emergency visits in adults presented with anaphylaxis. 64% of patients received their first medical help later than 30 min after symptom onset. 67% of patients received adrenaline, 85% oral antihistamines, and 89% received IV glucocorticosteroids. 46/100 patients were discharged directly from the ED, of which 87% received further medical prescriptions for self-administration: 67% corticosteroids, 83% antihistamines, and 9% intramuscular adrenaline. 74% were instructed to consult an allergologist for adequate diagnosis. 54/100 patients were hospitalized.

CONCLUSION

The majority of patients were treated according to the EAACI guidelines for management of anaphylaxis, but only a minority received the recommended adrenaline auto-injector for self-administration at discharge. Because the majority of patients received medical help later than 30 min after symptom onset, adrenaline auto-injector prescription is a necessity. The low rate of doctors prescribing adrenaline auto-injectors in the ED setting underlines the need to train doctors of various backgrounds in prevention and treatment of anaphylaxis and the close collaboration with allergologists.

Australian and New Zealand Anaesthetic Allergy Group/ Australian and New Zealand College of Anaesthetists Perioperative Anaphylaxis Management Guidelines

Anaphylaxis is an uncommon but important cause of serious morbidity and even mortality in the perioperative period. The Australian and New Zealand College of Anaesthetists (ANZCA) with the Australian and New Zealand Anaesthetic Allergy Group (ANZAAG) have developed clinical management guidelines that include six crisis management cards. The content of the guidelines and cards is based on published literature and other international guidelines for the management of anaesthesia-related and non–anaesthesia-related anaphylaxis. The evidence is summarised in the associated background paper (Perioperative Anaphylaxis Management Guidelines [2016] www.anzca.edu.au/resources/endorsed-guidelines and www.anzaag.com/Mgmt%20Resources.aspx ). These guidelines are intended to apply to anaphylaxis occurring only during the perioperative period. They are not intended to apply to anaphylaxis outside the setting of dedicated monitoring and management by an anaesthetist. In this paper guidelines will be presented along with a brief background to their development.

Anaphylactic shock caused by intramuscular injection of midazolam during the perioperative period: a case report

Although anaphylactic shock during the perioperative period is rare, it can be lethal due to severe cardiovascular and respiratory collapse. Midazolam is generally used as premedication for relieving anxiety about the operation, and the danger of anaphylactic shock after intramuscular injection is not widely recognized. We report the first case of anaphylactic shock occurring during the perioperative period after intramuscular injection of midazolam. Since anaphylactic shock after intramuscular injection can be of slow onset, the operation should be delayed if an anaphylactic reaction is suspected, even if the symptoms are limited. In addition, anesthesiologists should be prepared for the occurrence of anaphylaxis at any time in the perioperative period.

Adverse reactions to snake antivenom, and their prevention and treatment

Antivenom is the mainstay of treatment of snakebite envenoming. However, adverse reactions to snake antivenom that is available are common in many parts of the world where snakebite is prevalent. Both acute (anaphylactic or pyrogenic) and delayed (serum sickness type) reactions occur. Acute reactions are usually mild but severe systemic anaphylaxis may develop, often within an hour or so of exposure to antivenom. Serum sickness after antivenom has a delayed onset between 5 and 14 days after its administration. Ultimately, the prevention reactions will depend mainly on improving the quality of antivenom. Until these overdue improvements take place, doctors will have to depend on pharmacological prophylaxis, where the search for the best prophylactic agent is still on-going, as well as careful observation of patients receiving antivenom in preparation for prompt management of acute as well as delayed reactions when they occur.

Anaphylaxis audit in a busy metropolitan Emergency Department: a review of real life management compared to best practice

Background

Deficiencies in anaphylaxis management in Emergency Departments is well recognised despite established guidelines for its treatment.

Objective

To identify deficiencies in the management of anaphylaxis in a busy metropolitan Emergency Department and determine if an education intervention could correct these.

Methods

Paediatric and adult admissions to the Emergency Department of a busy hospital were tracked over a 10-month period with a targeted educational program being instituted at 5 months. The electronic records were retrospectively reviewed looking for cases of anaphylaxis and milder forms of immediate type allergic reactions presenting with a combination of urticaria and nonairway threatening angioedema. Anaphylaxis presentation was graded using the Brown grading system. Use of all medication during resuscitation was documented. Observation period before discharge and referral to specialist unit for follow-up was noted.

Results

In the first 5 months, 38 patients fulfilled our criteria. Three had severe anaphylaxis, 13 had moderately severe anaphylaxis and 12 had urticaria and angioedema without anaphylaxis. Anaphylaxis was not always recognised or graded leading to inappropriate management with adrenaline often being withheld. Promethazine, usually given in parenteral form, was frequently administered. Observation time was often inadequate. Referral to an immunologist was not universally followed through. Following the educational intervention 58 patients fulfilled our criteria over the next 5 months. The appropriate use of adrenaline increased by 21% and the use of sedating antihistamines decreased by 16%, while the number of referrals to an immunologist increased by 24%. There was an 11% reduction in the number of patients who were observed for at least 4 hours.

Conclusion

A number of deficiencies in the management of anaphylaxis presentations have been identified. Targeted educational activities aimed at the Emergency Department hospital staff may improve outcomes.

Immediate-type hypersensitivity drug reactions

Hypersensitivity reactions including anaphylaxis have been reported for nearly all classes of therapeutic reagents and these reactions can occur within minutes to hours of exposure. These reactions are unpredictable, not directly related to dose or the pharmacological action of the drug and have a relatively high mortality risk. This review will focus on the clinical presentation, immune mechanisms, diagnosis and prevention of the most serious form of immediate onset drug hypersensitivity reaction, anaphylaxis. The incidence of drug-induced anaphylaxis deaths appears to be increasing and our understanding of the multiple and complex reasons for the unpredictable nature of anaphylaxis to drugs is also expanding. This review highlights the importance of enhancing our understanding of the biology of the patient (i.e. immune response, genetics) as well as the pharmacology and chemistry of the drug when investigating, diagnosing and treating drug hypersensitivity. Misdiagnosis of drug hypersensitivity leads to substantial patient risk and cost. Although oral provocation is often considered the gold standard of diagnosis, it can pose a potential risk to the patient. There is an urgent need to improve and standardize diagnostic testing and desensitization protocols as other diagnostic tests currently available for assessment of immediate drug allergy are not highly predictive.

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.

Anaphylaxis attributed to exercise: considerations for sports medicine specialists

Anaphylaxis is an unanticipated, acute, and sometimes life-threatening systemic reaction with variable clinical presentations that is typically mediated by immunoglobulin E and causes degranulation of mast cells and basophils. The onset of symptoms can occur within minutes or hours after exposure to a known or suspected trigger, and reactions sometimes progress very rapidly, which can lead to death. One trigger of anaphylaxis in younger adults is moderately intense physical exercise, which has been termed exercise-induced anaphylaxis (EIA). Although rare, EIA should be recognized as a distinct and potentially life-threatening form of physical allergy, and is often undetected or inadequately treated. The ingestion of specific foods, including seafood, tree nuts, and wheat, or a nonspecific meal consisting of multiple food components shortly before or after physical exertion, is sometimes, but not always, the principal precipitant of EIA. This article briefly explores the current hypotheses on the role of immunoglobulin E, response mediators, and physiologic changes that bring on EIA, and discusses the current recommendations for diagnosis, including allergen challenge and laboratory testing, emergency care, and long-term prevention and patient follow-up. Accurate diagnosis of EIA is critical to providing lifesaving therapy and care plans to patients at risk. With respect to the medical management of EIA, mainstay therapy with epinephrine is described. For those with a known history of EIA, a comprehensive anaphylaxis action plan is central to successful patient management. Furthermore, patient education is necessary to heighten awareness of the signs and symptoms of EIA and appropriate strategies for allergen avoidance and self-management of anaphylactic episodes with self-injectable epinephrine.

Pediatricians manage anaphylaxis poorly regardless of episode severity

BACKGROUND

No information exists on how the knowledge or the practice of pediatricians regarding anaphylaxis episodes vary with episode severity. The aim of this study was to assess and compare pediatrician knowledge on the management of mild and severe anaphylaxis using clinical scenarios and to determine factors that affect their decisions.

METHODS

A questionnaire consisting of eight questions on the diagnosis and management of anaphylaxis was distributed at two national congresses. A uniform answer box including possible response choices was given below each question, and respondents were asked to check the answers that they thought appropriate. The management of mild and severe anaphylaxis was examined using two clinical case scenarios involving initial treatment, monitoring, and discharge recommendations.

RESULTS

Four hundred and ten questionnaires were analyzed. The percentage of pediatricians who correctly answered all questions on the management of mild and severe anaphylaxis scenarios was 11.3% and 3.2%, respectively. Pediatricians did significantly better with initial treatment, but they were less knowledgeable with respect to observation time and discharge criteria in the mild anaphylaxis case scenario compared with the severe one (both P < 0.001). Multiple logistic regression analysis identified only working in an emergency department or intensive care unit as significantly predicting correct diagnosis of anaphylaxis among pediatricians (P = 0.01, 95% confidence interval: 0.11-0.57). No pediatrician-related factors predicted physician knowledge on the management of anaphylaxis.

CONCLUSIONS

Pediatricians have difficulty with different steps in managing mild and severe anaphylaxis. Their deficiencies in management may result in failure to prevent recurrences of mild anaphylaxis and may increase mortality in severe anaphylaxis.

Snakebite in Australia: a practical approach to diagnosis and treatment

Snakebite is a potential medical emergency and must receive high-priority assessment and treatment, even in patients who initially appear well. Patients should be treated in hospitals with onsite laboratory facilities, appropriate antivenom stocks and a clinician capable of treating complications such as anaphylaxis. All patients with suspected snakebite should be admitted to a suitable clinical unit, such as an emergency short-stay unit, for at least 12 hours after the bite. Serial blood testing (activated partial thromboplastin time, international normalised ratio and creatine kinase level) and neurological examinations should be done for all patients. Most snakebites will not result in significant envenoming and do not require antivenom. Antivenom should be administered as soon as there is evidence of envenoming. Evidence of systemic envenoming includes venom-induced consumption coagulopathy, sudden collapse, myotoxicity, neurotoxicity, thrombotic microangiopathy and renal impairment. Venomous snake groups each cause a characteristic clinical syndrome, which can be used in combination with local geographical distribution information to determine the probable snake involved and appropriate antivenom to use. The Snake Venom Detection Kit may assist in regions where the range of possible snakes is too broad to allow the use of monovalent antivenoms. When the snake identification remains unclear, two monovalent antivenoms (eg, brown snake and tiger snake antivenom) that cover possible snakes, or a polyvalent antivenom, can be used. One vial of the relevant antivenom is sufficient to bind all circulating venom. However, recovery may be delayed as many clinical and laboratory effects of venom are not immediately reversible. For expert advice on envenoming, contact the National Poisons Information Centre on 13 11 26.

H2-antihistamines for the treatment of anaphylaxis with and without shock: a systematic review

BACKGROUND

Anaphylaxis is a serious allergic or hypersensitivity reaction, which is rapid in onset and sometimes can prove fatal. Although H2-antihistamines are often administered for emergency treatment in anaphylaxis, there is uncertainty about their effectiveness in this disease.

OBJECTIVE

To assess the benefits and harms of H2-antihistamines in the treatment of anaphylaxis.

METHODS

A systematic review was performed of randomized controlled trials and quasi-randomized controlled trials comparing H2-antihistamines with placebo or no intervention in patients with anaphylaxis.

RESULTS

The authors failed to identify any eligible studies for inclusion in this systematic review.

CONCLUSION

When H2-antihistamines are recommended for anaphylaxis treatment, the status of the evidence base supporting their use should be described. Well-designed randomized controlled trials investigating the role of H2-antihistamines in anaphylaxis treatment are urgently needed.

Acute pulmonary edema following inflation of arterial tourniquet

Arterial tourniquets are used as one of the methods for reducing blood loss and for allowing blood free surgical field. A 20-year-old, 45 kg healthy female with a sphere shaped pendunculated hemangioma in the popliteal fossa of her left lower limb was applied with arterial tourniquet after exsanguination. The procedure was performed under general anesthesia. Soon after exsanguination and tourniquet inflation, the patient developed pulmonary edema which subsided after deflating the tourniquet. The clinical evolution, treatment and pathophysiology of this complication are described.