The Epidemiology of Anaphylaxis

"Antibiotic hypersensitivity reactions in Cystic Fibrosis: A thorough inspection on a stumbling block in patient care"

One hurdle in the management of CF, a disease characterized by progressive endobronchial infection, is the presence of hypersensitivity reactions to antimicrobials due to prolonged and repetitive treatment courses. The aim of this review is to compile existing data and provide insight to medical professionals on a long-debated topic for optimum patient care. Clinical studies were inducted from the last 15 years and filtered based on their relativity to drug hypersensitivity reactions (DHRs), antibiotics and CF. After completing the selection process, 10 clinical studies were thoroughly examined. The most frequent antibiotic group related to DHRs were beta-lactams. Frequency of the most common overall type of reaction (immediate or nonimmediate) differed among clinical studies. Although severe reactions seem rare comparatively, they do occur during and even after completion of treatment regimens. The prevalence of true drug allergies should be confirmed using a variety of tests available, however, should not be confused with overall DHR rates. Genetic mutations, gender and lifetime antibiotic dose were not related with an increased risk for DHR development. On the contrary, the most important factor according to most studies was the cumulative antimicrobial dose in a given period of time, especially when delivered parenterally. DHRs are an indisputable problem in the management of CF patients. Understanding possible risk factors and increased awareness is vital in both hospital and outpatient settings as early detection can decrease the severity of the reactions.

Circulating serum profile of small non-coding RNAs in patients with anaphylaxis beyond microRNAs

Introduction

Anaphylaxis is the most severe manifestation of allergic disorders. Currently, an increasing number of cells, pathways and molecules involved in the etiopathogenesis of anaphylaxis are being discovered. However, there are no conclusive biomarkers to confirm its diagnosis. Small non-coding RNAs (sncRNAs) are 18-200 nucleotide molecules that can be divided into: microRNAs (miRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), small nuclear RNAs (snRNAs), transference RNA derived fragments (tRFs) and YRNA derived fragments (YRFs). These molecules participate in cell-cell communication modulating various physiological processes and have been postulated as non-invasive biomarkers of several pathologies. Therefore, in this study we characterized the serum circulating profile of other sncRNA beyond miRNAs in two populations of 5 adults and 5 children with drug- and food-mediated anaphylaxis, respectively.

Methods

Samples were obtained from each patient under two different conditions: during anaphylaxis and 14 days after the reaction (control). The sncRNA analysis was carried out by Next Generation Sequencing (NGS).

Results

A total of 671 sncRNAs (3 piRNAs, 74 snoRNAs, 54 snRNAs, 348 tRFs and 192 YRFs) were identified in adults with drug-induced anaphylaxis, while 612 sncRNAs (2 piRNAs, 73 snoRNAs, 52 snRNAs, 321 tRFs and 164 YRFs) were characterized in children with food-mediated anaphylaxis. However, only 33 (1 piRNA, 4 snoRNAs, 1 snRNAs, 7 tRFs and 20 YRFs) and 80 (4 snoRNAs, 6 snRNAs, 54 tRFs and 16 YRFs) of them were statistically different between both conditions, respectively. Among them, only three (Y_RNA.394, Y_RNA.781 and SCARNA2) were common to both adults and children analysis.

Discussion

This study provides a differential profile of circulating serum sncRNAs beyond miRNAs in patients with anaphylaxis, postulating them as candidate biomarkers for this pathological event and as novel mediators of the reaction.

Managing anaphylaxis: Epinephrine, antihistamines, and corticosteroids: More than 10 years of Cross-Canada Anaphylaxis REgistry data

BACKGROUND

Epinephrine is the first-line treatment for anaphylaxis but is often replaced with antihistamines or corticosteroids. Delayed epinephrine administration is a risk factor for fatal anaphylaxis. Convincing data on the role of antihistamines and corticosteroids in anaphylaxis management are sparse.

OBJECTIVE

To establish the impact of prehospital treatment with epinephrine, antihistamines, and/or corticosteroids on anaphylaxis management.

METHODS

Patients presenting with anaphylaxis were recruited prospectively and retrospectively in 10 Canadian and 1 Israeli emergency departments (EDs) between April 2011 and August 2022, as part of the Cross-Canada Anaphylaxis REgistry. Data on anaphylaxis cases were collected using a standardized form. Primary outcomes were uncontrolled reactions (>2 doses of epinephrine in ED), no prehospital epinephrine use, use of intravenous fluids in ED, and hospital admission. Multivariate regression was used to identify factors associated with primary outcomes.

RESULTS

Among 5364 reactions recorded, median age was 8.8 years (IQR, 3.78-16.9); 54.9% of the patients were males, and 52.5% had a known food allergy. In the prehospital setting, 37.9% received epinephrine; 44.3% received antihistamines, and 3.15% received corticosteroids. Uncontrolled reactions happened in 250 reactions. Patients treated with prehospital epinephrine were less likely to have uncontrolled reactions (adjusted odds ratio [aOR], 0.955 [95% CI, 0.943-0.967]), receive intravenous fluids in ED (aOR, 0.976 [95% CI, 0.959-0.992]), and to be admitted after the reaction (aOR, 0.964 [95% CI, 0.949-0.980]). Patients treated with prehospital antihistamines were less likely to have uncontrolled reactions (aOR, 0.978 [95% CI, 0.967-0.989]) and to be admitted after the reaction (aOR, 0.963 [95% CI, 0.949-0.977]). Patients who received prehospital corticosteroids were more likely to require intravenous fluids in ED (aOR, 1.059 [95% CI, 1.013-1.107]) and be admitted (aOR, 1.232 [95% CI, 1.181-1.286]).

CONCLUSION

Our findings in this predominantly pediatric population support the early use of epinephrine and suggest a beneficial effect of antihistamines. Corticosteroid use in anaphylaxis should be revisited.

Sugammadex-Induced Anaphylactic Shock Reversed With Short-Term Continuous Veno-Venous Hemodiafiltration: A Case Report

Anaphylaxis is a life-threatening, systemic, hypersensitivity reaction, manifested by urticaria, hypotension, and respiratory symptoms. Antigens that are cleared renally may have protracted exposure in patients with impaired renal function, resulting in prolonged and refractory anaphylactic shock. After administration of sugammadex, a 47-year-old man developed prolonged, refractory anaphylactic shock, with anuria due to acute kidney injury. The patient was treated with continuous, short-term, veno-venous hemodiafiltration. Initiating this therapy in patients with refractory anaphylactic shock and anuria due to an antigen that is excreted renally can expedite recovery.

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.

Retrospective evaluation of hypersensitivity reactions and anaphylaxis in dogs (2003-2014): 86 cases

OBJECTIVE

To characterize anaphylactic reactions in dogs, including clinical signs, severity, treatments, prognosis, and estimated incidence. To determine whether glucocorticoids influence clinical recovery and survival.

DESIGN

Retrospective study between January 1, 2003 and April 28, 2014.

SETTING

University teaching hospital.

ANIMALS

Eighty-six dogs treated for a type I hypersensitivity reaction. Nineteen dogs fulfilled the criteria for anaphylaxis, and 67 dogs had mild cutaneous reactions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The estimated incidence was 0.04% for anaphylaxis and 0.15% for mild hypersensitivity reactions. The female:male ratio (2.3:1) was significantly higher (P = 0.032) compared to our source population (ratio of 1:1.158). Vaccines were the most frequent trigger for anaphylaxis (57.9%) and mild hypersensitivity reactions (28.4%). Seventy-four (86%) dogs had cutaneous signs, and 11 (57.9%) dogs with anaphylaxis had no cutaneous signs reported. Forty-two (48.8%) dogs received both an H1 antagonist and a glucocorticoid, 34 (39.5%) dogs received an H1 antagonist only, and 6 (6.9%) dogs received a glucocorticoid only. The majority of the dogs survived, and 1 was euthanized due to complications. Clinical signs associated with nonsurvival included respiratory signs (P = 0.006), particularly respiratory distress (P < 0.00001) and cyanosis (P < 0.00001), and circulatory shock (P = 0.005). The analysis of the interaction between etiology, clinical signs, treatment, and outcome did not show any association between pairs of variables.

CONCLUSIONS

In the current study, anaphylaxis had a relatively good prognosis, and cutaneous signs were not always present. Based on the present data, the use of glucocorticoids to treat mild type I hypersensitivity reactions and anaphylaxis in dogs was not associated with clinical improvement or survival.

Mast Cells and Basophils in IgE-Independent Anaphylaxis

Anaphylaxis is a life-threatening or even fatal systemic hypersensitivity reaction. The incidence of anaphylaxis has risen at an alarming rate in the past decades in the majority of countries. Generally, the most common causes of severe or fatal anaphylaxis are medication, foods and Hymenoptera venoms. Anaphylactic reactions are characterized by the activation of mast cells and basophils and the release of mediators. These cells express a variety of receptors that enable them to respond to a wide range of stimulants. Most studies of anaphylaxis focus on IgE-dependent reactions. The mast cell has long been regarded as the main effector cell involved in IgE-mediated anaphylaxis. This paper reviews IgE-independent anaphylaxis, with special emphasis on mast cells, basophils, anaphylactic mediators, risk factors, triggers, and management.

Endotracheal Intubation of Difficult Airways in Emergency Settings: A Guide for Innovators

Over 400,000 Americans are intubated in emergency settings annually, with indications ranging from respiratory failure to airway obstructions to anaphylaxis. About 12.7% of emergency intubations are unsuccessful on the first attempt. Failure to intubate on the first attempt is associated with a higher likelihood of adverse events, including oxygen desaturation, aspiration, trauma to soft tissue, dysrhythmia, hypotension, and cardiac arrest. Difficult airways, as classified on an established clinical scale, are found in up to 30% of emergency department (ED) patients and are a significant contributor to failure to intubate. Difficult intubations have been associated with longer lengths of stay and significantly greater costs than standard intubations. There exists a wide range of airway management devices, both invasive and noninvasive, which are available in the emergency setting to accommodate difficult airways. Yet, first-pass success rates remain variable and leave room for improvement. In this article, we review the disease states most correlated with intubation, the current landscape of emergency airway management technologies, and the market potential for innovation. The aim of this review is to inspire new technologies to assist difficult airway management, given the substantial opportunity for translation due to two key-value signposts of medical innovation: the potential to decrease cost and the potential to improve clinical outcomes.

Investigation of the underuse of adrenaline (epinephrine) and prognosis among patients with anaphylaxis at emergency department admission

Background

Anaphylaxis is a potentially fatal condition; in severe cases of anaphylaxis, the cardiovascular system is often heavily involved. Adrenaline (epinephrine) is a cornerstone of the initial treatment of anaphylaxis. The use of epinephrine remains below expectations in clinical practice. Whether the underuse of epinephrine affects the prognosis of patients with anaphylaxis is still unclear.

Materials and methods

This retrospective study included patients with anaphylaxis between 2011 and 2020 who were admitted to an emergency department (ED) in Taiwan. All patients were divided into two groups based on the use of epinephrine (or not), and we compared the demographic characteristics, allergens, clinical manifestations, management, and patient outcomes.

Results

We reviewed the records of 314 subjects (216 males, 98 females; mean age: 52.78 ± 16.02 years) who visited our ED due to anaphylaxis; 107 (34.1%) and 207 (65.9%) patients were categorized into the epinephrine use group and the non-epinephrine use group, respectively. Arrival via ambulance (p = 0.019), hypotension (p = 0.002), airway compromise (p < 0.001) and altered consciousness (p < 0.001) were the deciding factors for epinephrine use among anaphylactic patients in the ED. The epinephrine use group had higher rates of other inotropic agent usage and fluid challenge. More than 90% of patients received bed rest, steroids, antihistamines, and monitoring. The epinephrine use group had a longer ED length of stay (387.64 ± 374.71 vs. 313.06 ± 238.99 min, p = 0.03) and a greater need of hospitalization. Among all severe symptoms, hypotension was the most tolerated decision factor for not using epinephrine. In this retrospective analysis, some patients with serious anaphylaxis did not experience adverse outcomes or death even without the use of epinephrine at ED admission. Emergent care focuses first on the airway, breathing, and circulation (ABC) and may compensate for the underusage of epinephrine. This could be the reason why epinephrine was underused among patients with anaphylaxis in the ED.

Conclusion

In summary, early ABC management continues to play an important role in treating patients with severe anaphylaxis, even when epinephrine is not immediately available in clinical scenarios.

A Case of "Anaphylaxis" to NovoSeven in a Hemophiliac Patient

Anaphylaxis is a life-threatening emergency that may be confused with other less serious conditions. The onset of true anaphylaxis typically occurs within minutes following exposure to an offending agent, and it can variably include dyspnea/wheezing, hemodynamic compromise, rash, hives/pruritus, swelling, or gastrointestinal symptoms. The absence of an expected association between exposure(s) and classic symptoms should lead to the consideration of alternative diagnoses. Here, we describe the course of a patient with hemophilia B who developed stridor and wheezing after exposure to the recombinant factor VII, NovoSeven, and tranexamic acid (TXA) for the management of hematomas. Due to a reported prior history of anaphylaxis to multiple factor replacements, the patient's initial management included NovoSeven with steroid/antihistamine prophylaxes and close monitoring with epinephrine at the bedside. Despite the administration of prophylaxis, the patient developed significant stridor, was treated with epinephrine and nebulizers and additional steroids, and was transferred to the intensive care unit. There, a pattern of NovoSeven administration followed variably by wheezing and stridor continued for two days until the patient's respiratory condition was predictable and stable. The patient's subsequent clinical course following transfer to the general medical ward was not consistent with anaphylaxis. This case highlights the importance of evaluating for mimickers of anaphylaxis, especially where only select symptoms such as stridor and wheezing are present without other serious signs of anaphylaxis such as hypoxemia, hypotension, or significant tachycardia.

[Characterization of patients with anaphylaxis in a tertiary hospital in Medellin, Colombia (2009-2019)]

OBJECTIVE

To characterize demographically and clinically the patients with anaphylaxis treated in a third level health institution in Medellin, Colombia.

METHODS

A cross-sectional descriptive observational study was carried out, which includedpatients were diagnosed with anaphylaxis between 2009 and 2019. Information was retrieved from medical records through a collection instrument. Subsequently, a descriptive statistical analysis of proportions and measures of central tendency of the variables of interest was performed.

RESULTS

A total of 1820 records were reviewed and data from 253 patients were included. Among the reported comorbidities, drug allergy was the most prevalent (28%). The most frequent manifestations of anaphylaxis were cutaneous and respiratory. Most of the cases presented basal tryptase values ≤ 11.4 ng/mL (94.7%). Different etiological agents (food, drugs, insects and latex) were reported, and their frequency varied according to age. Adrenaline, steroids, and antihistamines were the treatments of choice in 39.9, 34.3, and 39.9% of cases, respectively.

CONCLUSIONS

The characteristics of anaphylaxis in a medical center in Colombia coincide with those reported in Latin American. The treatment of anaphylaxis is not standardized, which makes it necessary to educate the health personnel and develop national guidelines.

Different age groups present different clinics in anaphylaxis with children: one size does not fit all children

BACKGROUND

Childhood anaphylaxis presents with a heterogeneous clinic. Elicitors and epidemiologic factors associated with anaphylaxis differ with age, geographic location and lifestyle. This study aimed to determine the clinical features and age-specific patterns of childhood anaphylaxis in a single referral center in Turkey.

METHODS

We conducted a retrospective study of anaphylaxis in children aged between 0 and 18 years of age, attending an allergy department in a children's hospital.

RESULTS

A total of 95 children diagnosed with anaphylaxis were analyzed. Among all, 35.8% of the first anaphylaxis episodes occurred ininfancy and 57.9% in preschool age. Foods were the most common culprits (57.9%) and followed by drugs (15.8%). Patients with foodinduced anaphylaxis were younger in age (p < 0.001). Food-related anaphylaxis was most common with cow's milk (36.4%) and followed by tree nuts (20%). Cow's milk played a significant role as a trigger in infancy, and tree nuts as a trigger in preschoolers and school-age children. Mucocutaneous manifestations were almost universally present (94.7%), followed by respiratory compromise (56.8%), with gastrointestinal (55.8%), cardiovascular (9.5%), and neurologic (4.2%) symptoms being less common. Respiratory and cardiovascular system-related symptoms were found more frequently in school-age children (p = 0.02 and p = 0.014, respectively). The severity of anaphylaxis was higher in school-age children (p = 0.015).

DISCUSSION

Findings reveal that children diagnosed with anaphylaxis differ in terms of etiological and clinical findings according to age groups. This difference shows the dynamically changing clinic of anaphylaxis over time and the importance of evaluating childhood anaphylaxis according to age groups.

A mast cell-thermoregulatory neuron circuit axis regulates hypothermia in anaphylaxis

IgE-mediated anaphylaxis is an acute life-threatening systemic reaction to allergens, including certain foods and venoms. Anaphylaxis is triggered when blood-borne allergens activate IgE-bound perivascular mast cells (MCs) throughout the body, causing an extensive systemic release of MC mediators. Through precipitating vasodilatation and vascular leakage, these mediators are believed to trigger a sharp drop in blood pressure in humans and in core body temperature in animals. We report that the IgE/MC-mediated drop in body temperature in mice associated with anaphylaxis also requires the body's thermoregulatory neural circuit. This circuit is activated when granule-borne chymase from MCs is deposited on proximal TRPV1⁺ sensory neurons and stimulates them via protease-activated receptor-1. This triggers the activation of the body's thermoregulatory neural network, which rapidly attenuates brown adipose tissue thermogenesis to cause hypothermia. Mice deficient in either chymase or TRPV1 exhibited limited IgE-mediated anaphylaxis, and, in wild-type mice, anaphylaxis could be recapitulated simply by systemically activating TRPV1⁺ sensory neurons. Thus, in addition to their well-known effects on the vasculature, MC products, especially chymase, promote IgE-mediated anaphylaxis by activating the thermoregulatory neural circuit.

Symjepi Epinephrine Injection Device Deconstruction and Residual Medication Retrieval in an Austere Environment

Epinephrine is the primary therapy in the treatment of anaphylaxis. Epinephrine delivery devices are commonplace in out-of-hospital care of anaphylaxis because they administer a standardized dose of epinephrine, limit human error, and allow for ease of use by the operator. However, a major limitation of these devices is the single-use nature of the products. In an austere setting, the ability to obtain additional doses from an autoinjector may prevent further progression of anaphylaxis. Previous articles have demonstrated the deconstruction of spring-loaded epinephrine autoinjectors to extract additional medication doses. This article provides instruction and videography, outlining the process of deconstructing and obtaining additional doses of epinephrine from the Symjepi prefilled syringe.

Efficacy and safety of food allergy oral immunotherapy in adults

BACKGROUND

Oral immunotherapy (OIT) is an emerging method for treating food allergy in children. However, data regarding adults undergoing this process are lacking.

METHODS

We retrospectively analyzed the medical records of patients with food allergy aged ≥17 years who completed OIT treatment between April 2010 and December 2020 at Shamir Medical Center. Data were compared with that of children aged 4 to <11 years and adolescents aged ≥11 to 17 treated during the same time period.

RESULTS

A total of 96 adults at a median age of 22.3 years who underwent OIT for milk (n = 53), peanut (n = 18), sesame (n = 7), egg (n = 5), and tree nuts (n = 13) were analyzed and compared with 1299 children and 309 adolescents. Adults experienced more adverse reactions requiring injectable epinephrine, both during in-clinic up-dosing (49% vs. 15.9% and 26.5% for children and adolescents, respectively, p < 0.0001) and during home treatment (22.9% vs. 12.4%, p = 0.007 for children, and 17.5%, p = 0.23 for adolescents). Most adults (61.5%) were fully desensitized, but the rates of full desensitization were significantly lower than children (73.4%, p = 0.013). Significantly more adults (28.3%) undergoing milk OIT failed treatment than children (14.3%, p = 0.015) and adolescents (14.1%, p = 0.022), while failure rates in adults undergoing OIT for other foods were low (9.3%) and comparable with children and adolescents.

CONCLUSIONS

OIT is successful in desensitizing most adults with IgE-mediated food allergy. Adults undergoing milk OIT are at increased risk for severe reactions and for OIT failure while failure rates in adults undergoing OIT for other foods are low.

Direct Versus Indirect Query Performance of ICD-9/-10 Coding to Identify Anaphylaxis

BACKGROUND

Anaphylaxis is an often under =diagnosed, severe allergic event for which epidemiological data are sporadic. Researchers have leveraged administrative and claims data algorithms to study large databases of anaphylactic events; however, little longitudinal data analysis is available after transition to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM).

OBJECTIVE

Study longitudinal trends in anaphylaxis incidence using direct and indirect query methods.

METHODS

Emergency department (ED) and inpatient data were analyzed from a large state health care administration database from 2011 to 2020. Incidence was calculated using direct queries of anaphylaxis ICD-9-CM and ICD-10-CM codes and indirect queries using a symptom-based ICD-9-CM algorithm and forward mapped ICD-10-CM version to identify undiagnosed anaphylaxis episodes and to assess algorithm performance at the population level.

RESULTS

An average of 2.4 million inpatient and 7.5 million ED observations/y were analyzed. Using the direct query method, annual ED anaphylaxis cases increased steadily from 1,454 (2011) to 4,029 (2019) then declined to 3,341 in 2020 during the coronavirus disease 2019 (COVID-19) pandemic. In contrast, inpatient cases remained relatively steady, with a slight decline after 2015 during the ICD version transition, until a significant drop occurred in 2020. Using the indirect queries, anaphylaxis cases increased markedly after the ICD transition year, especially involving drug-related anaphylaxis.

CONCLUSIONS

Nontypical drug associations with anaphylaxis episodes using the ICD-10-CM version of the algorithm suggest poor performance with drug-related codes. Further, the increased granularity of ICD-10-CM identified potential limitations of a previously validated symptom-based ICD-9-CM algorithm used to detect undiagnosed cases.

Appearance of food-dependent exercise-induced anaphylaxis as an inflammatory disease: a pediatric case report and differential diagnosis

Anaphylaxis is the most serious of all allergic reactions. Despite advances in the knowledge of anaphylaxis, its clinical manifestations continue to be under-recognized. Indeed, proper diagnosis of anaphylaxis is often missed, and the treatment is delayed. The underlying causes are still under investigation globally. Inflammation represents the cornerstone of pathophysiology of anaphylaxis. Food-dependent exercise-induced anaphylaxis (FDEIA) is a rare clinical manifestation characterized by a chronological sequence in which food ingestion followed by physical exercise leads to anaphylaxis. Its mechanisms are yet to be fully explained. We report the case of a 14-year-old Chinese male who lost consciousness while undergoing physical activity at school. Several differential diagnoses were considered such as hypovolemic shock, septic shock, anaphylactic shock or neurological adverse event. Finally, the diagnosis of FDEIA was made. This case highlights the difficulties in diagnosing FDEIA and its management, especially when the clinical history is not complete and detailed.

Integrative transcriptomic analysis in human and mouse model of anaphylaxis identifies gene signatures associated with cell movement, migration and neuroinflammatory signalling

Background

Anaphylaxis is an acute life-threatening allergic reaction and a concern at a global level; therefore, further progress in understanding the underlying mechanisms and more effective strategies for diagnosis, prevention and management are needed.

Objective

We sought to identify the global architecture of blood transcriptomic features of anaphylaxis by integrating expression data from human patients and mouse model of anaphylaxis.

Methods

Bulk RNA-sequencings of peripheral whole blood were performed in: i) 14 emergency department (ED) patients with acute anaphylaxis, predominantly to Hymenoptera venom, ii) 11 patients with peanut allergy undergoing double-blind, placebo-controlled food challenge (DBPCFC) to peanut, iii) murine model of IgE-mediated anaphylaxis. Integrative characterisation of differential gene expression, immune cell-type-specific gene expression profiles, and functional and pathway analysis was undertaken.

Results

1023 genes were commonly and significantly dysregulated during anaphylaxis in ED and DBPCFC patients; of those genes, 29 were also dysregulated in the mouse model. Cell-type-specific gene expression profiles showed a rapid downregulation of blood basophil and upregulation of neutrophil signature in ED and DBPCFC patients and the mouse model, but no consistent and/or significant differences were found for other blood cells. Functional and pathway analysis demonstrated that human and mouse blood transcriptomic signatures of anaphylaxis follow trajectories of upregulation of cell movement, migration and neuroinflammatory signalling, and downregulation of lipid activating nuclear receptors signalling.

Conclusion

Our study highlights the matched and extensive blood transcriptomic changes and suggests the involvement of discrete cellular components and upregulation of migration and neuroinflammatory pathways during anaphylaxis.

Causes and Diagnostic Usefulness of Tryptase Measurements for Anaphylaxis in a Korean Tertiary Care General Hospital

PURPOSE

The causes of anaphylaxis in a general hospital may differ from those occurring in a community setting. Underlying diseases in admitted patients and vague presenting symptoms can make the diagnosis of anaphylaxis difficult. Serum tryptase measurements may provide valuable evidence for diagnosing anaphylaxis in admitted patients.

MATERIALS AND METHODS

This study was designed as a retrospective study of 53 patients with an anaphylaxis episode at a Korean tertiary care general hospital. Tryptase levels were measured at baseline and different time points from the onset of anaphylaxis.

RESULTS

Drugs (42 cases; 79.2%) and foods (10 cases; 18.9%) were the most common causes of anaphylaxis. In drug-induced anaphylaxis, antibiotics (24.5%), anticancer medications, which included monoclonal antibodies (22.6%), and contrast agents (11.3%) were the most frequent causes. The muscle relaxant eperisone (5.7%), neuromuscular blocking agent rocuronium (5.7%), and its antagonist sugammadex (3.8%) were other frequent triggering agents. Wheat-dependent exercise-induced anaphylaxis was the most common entity in food-induced anaphylaxis. Tryptase concentrations were higher in patients with higher grades of anaphylaxis, as well as in accidental anaphylaxis, compared to meticulously provoked anaphylaxis. Overall diagnostic sensitivity was higher for tryptase algorithm criteria (≥[1.2×baseline+2] µg/L: 71.4%) than for abnormal tryptase level criteria (≥11.4 µg/L: 52.8%).

CONCLUSION

The triggers of anaphylaxis in a Korean tertiary care hospital were diverse, including beta-lactam antibiotics, anticancer medications, contrast medias, eperisone, nonsteroidal anti-inflammatory drugs, rocuronium, sugammadex, and wheat. Tryptase measurements provided valuable evidence for diagnosis, and the sensitivity of algorithm criteria was superior to that of the abnormal value criteria.

Improving Methods of Identifying Anaphylaxis for Medical Product Safety Surveillance Using Natural Language Processing and Machine Learning

We sought to determine whether machine learning and natural language processing (NLP) applied to electronic medical records could improve performance of automated health-care claims-based algorithms to identify anaphylaxis events using data on 516 patients with outpatient, emergency department, or inpatient anaphylaxis diagnosis codes during 2015-2019 in 2 integrated health-care institutions in the Northwest United States. We used one site's manually reviewed gold-standard outcomes data for model development and the other's for external validation based on cross-validated area under the receiver operating characteristic curve (AUC), positive predictive value (PPV), and sensitivity. In the development site 154 (64%) of 239 potential events met adjudication criteria for anaphylaxis compared with 180 (65%) of 277 in the validation site. Logistic regression models using only structured claims data achieved a cross-validated AUC of 0.58 (95% CI: 0.54, 0.63). Machine learning improved cross-validated AUC to 0.62 (0.58, 0.66); incorporating NLP-derived covariates further increased cross-validated AUCs to 0.70 (0.66, 0.75) in development and 0.67 (0.63, 0.71) in external validation data. A classification threshold with cross-validated PPV of 79% and cross-validated sensitivity of 66% in development data had cross-validated PPV of 78% and cross-validated sensitivity of 56% in external data. Machine learning and NLP-derived data improved identification of validated anaphylaxis events.

Pediatric Anaphylaxis: A 20-Year Retrospective Analysis

BACKGROUND

Anaphylaxis is a steadily increasing global problem defined as an acute hypersensitivity multisystem reaction that is potentially fatal. In the pediatric age, the leading cause is food. In other allergic diseases, intrinsic heterogeneity has been reported in the clinical presentation, severity, and triggers of anaphylaxis. This study analyzes the features and management approach of the anaphylactic reactions in children evaluated at the pediatric clinic in Pavia.

MATERIALS AND METHODS

A retrospective study was conducted on patients with anaphylaxis between 2001 and 2021.

RESULTS

A total of 148 patients with a median age of 5 years were enrolled, and 80% of the patients had other atopic comorbidities that were correlated with the severity of anaphylaxis. The main trigger of anaphylaxis was food. Most reactions involved mucocutaneous, respiratory, and gastrointestinal systems, and occurred at home. Adrenaline was administered only in a minority of cases.

CONCLUSIONS

Considering that anaphylaxis is a potentially life-threatening condition requiring prompt management, the use of adrenaline should be implemented. Our data also suggest the importance of educating and spreading awareness of anaphylactic management within the medical community.

Risk factors of anaphylaxis in Korea: Identifying drug-induced anaphylaxis culprits using big data

Drug-induced anaphylaxis is a fatal medical condition whose incidence has been increasing continuously. Due to differences between genetic backgrounds and health care systems, different populations may be prone to various causative drugs. Using the Health Insurance Service and Assessment Service database, we investigated culprit drugs for drug-induced anaphylaxis and common medication risk factors in the Korean general population. We collected medical prescription histories within 3 days prior to anaphylaxis between January 2011 and December 2019 from the HIRA database. Designed as a case-crossover study, the attributable visits (case visits) were matched to medical visits (control visits) with the drug sets for each visit. We collected a list of medication risk factors for anaphylaxis and calculated the risk ratio of each agent using the chi-square test and conditional logistic regression analysis. A total of 159,473 individuals were listed in the database with a diagnosis of anaphylaxis in the HIRA from 2011 to 2019. After evaluating the suitability of control visits for matching with a case visit, 8168 subjects and 767 drugs were analyzed. The chi-square analysis identified 31 drugs as potential risk factors for drug-induced anaphylaxis in Korea. After applying a conditional logistic regression analysis for each agent, 5 drugs were found to be the common medication risk factors for drug-induced anaphylaxis: cefaclor, iopromide, iohexol, iomeprol, and tolperisone. We found 5 medication risk factors that showed the highest risk of drug-induced anaphylaxis and their degree of risk using an objective methodology in the Korean general population.

Anaphyl-Crisis: Rising Rates of Pediatric Anaphylaxis

OBJECTIVES

Anaphylaxis is a serious allergic reaction that has the potential to be life-threatening if not recognized and managed rapidly. Several regional studies have shown increased incidence of anaphylaxis over the past decade. The objectives of this study were to determine rates of pediatric anaphylaxis in southeast Michigan between January 1, 2010, and December 31, 2019, and to describe the epidemiology of pediatric patients presenting to emergency centers in southeast Michigan with anaphylaxis.

METHODS

We performed a retrospective chart review of all pediatric patients aged 0 to 17 years presenting to 2 large emergency centers from 2010 to 2019 with a diagnosis of anaphylaxis using International Classification of Diseases , Ninth and Tenth Revision , Clinical Modification codes. Epidemiological and visit data, including length of stay, use of intravenous medication, and emergency severity index, were extracted and analyzed. Pediatric anaphylaxis rates were calculated based on detected anaphylaxis cases divided by total pediatric emergency department visits to the 2 emergency centers. A Poisson regression model was used to predict rates of anaphylaxis per 100,000 emergency department visits.

RESULTS

One thousand three hundred ninety-one pediatric visits for anaphylaxis were identified during a period between January 1, 2010, and December 31, 2019. There was a significant rate of increase in pediatric anaphylaxis cases over the 10-year study period at both suburban emergency centers, with an annual increase of 21% and 13%. There was no significant change in trends in demographic factors. Most anaphylaxis cases were young, White males with private insurance. Most children did not receive intravenous medications (77%). The median length of stay increased by 1.5 hours over the study period and 92% of patients were discharged home.

CONCLUSIONS

Pediatric emergency center visits and length of stay for anaphylaxis in southeast Michigan have markedly increased over the past 10 years.

A Case Report of Lifesaving Intravenous Bolus Epinephrine Administration in a Case of Severe Refractory Anaphylactic Shock

Anaphylaxis is a life-threatening response to various types of allergens. Early recognition and management are crucial for reducing mortality. This case report highlights a 31-year-old male with a background of hypertension who presented to the emergency department with nausea, vomiting, right flank pain, headache, and elevated blood pressure (BP) of 212/134 mmHg. The patient was started on stat captopril 12.5 mg tablet and stat amlodipine 5 mg tablet for his high BP and stat diclofenac 75 mg (1 mg/kg) intramuscular (IM) for his flank pain. Two minutes later the patient started developing swelling of his mucosal membranes with no urticaria or rashes and his BP suddenly dropped and was unrecordable. First-line management was immediately initiated including the administration of two standard adult doses of IM epinephrine of 500 mcg each with a 5-minute interval. The BP remained undetectable; accordingly, a third IM epinephrine dose of 500 mcg was administered along with an intravenous (IV) epinephrine drip initiated at a rate of 4 mcg/min. The BP became 60/40 mmHg but kept dropping, thus an IV epinephrine bolus of 300 mcg (4 mcg/kg) was given along with the ongoing IV epinephrine drip. BP increased to 126/75 mmHg. While on the IV epinephrine drip the BP dropped again to 88/59 mmHg, a second IV epinephrine bolus of 200 mcg (2.6 mcg/kg) was given and the BP became 140/90 mmHg and recovery was achieved. Emergency cases require immediate recognition and intervention. Currently, IM epinephrine is the primary treatment for anaphylaxis. We hope our case report contributes to the database on severe refractory anaphylaxis by discussing a successful case where IV bolus epinephrine was used to prevent imminent cardiovascular collapse. Highlighting the need for appropriate escalation of management given the availability of physicians with expertise.

Cardiac arrest caused by anaphylaxis refractory to prompt management: A case series and review of the literature

BACKGROUND

Anaphylaxis is a potentially life-threatening condition that occurs in the emergency department (ED). Although anaphylaxis is rapidly recognized and treated in the hospital compared with that in the community, in some cases, it does not respond to proper management.

OBJECTIVE

The aim of this study is to describe our experience of cases of refractory anaphylaxis leading to cardiac arrest in hospital, to review their characteristics compared with those seen in the community, and to discuss the best management practices for anaphylaxis-induced cardiac arrest with a literature review.

METHODS

We reviewed the medical records of patients referred to the ED with possible in-hospital anaphylaxis between January 2017 and May 2021. According to the anaphylaxis protocol, epinephrine, corticosteroid, and antihistamine were administered immediately on-site at our institution before the study period. Refractory anaphylaxis was defined as the development of anaphylaxis-induced cardiac arrest even after following the anaphylaxis protocol.

RESULTS

A total of 246 cases were evaluated for possible anaphylaxis, with 236 cases meeting the criteria for a diagnosis of anaphylaxis. Among them, 178 patients showed the signs and symptoms of shock, and cardiac arrest occurred in 6 patients (2.5%). Of the six patients, three had a return of spontaneous circulation before admission to the ED, while two died due to refractory cardiac arrest despite resuscitation in the ED. Following post-cardiac arrest care, including temperature management, one patient who received extracorporeal cardiopulmonary resuscitation survived neurologically intact.

CONCLUSION

We present our case series to highlight the risk of developing refractory anaphylaxis with subsequent in-hospital cardiac arrest. Patients may progress to cardiac arrest within minutes despite prompt recognition and management. If patients present with potentially fatal symptoms, a more aggressive approach, including intravenous adrenaline infusion, should be taken.

Emergency department childhood anaphylaxis presentations in regional/remote Australia

AIM

Explore the prevalence of childhood anaphylaxis and clinical presentation of anaphylaxis in children across two regional emergency departments over a 7-year period.

METHODS

Retrospective audit of all children (0-18 years) presenting to emergency from 1 January 2010 to 31 December 2016 with anaphylaxis, defined by Australasian Society of Clinical Immunology and Allergy definitions and doctor diagnosis.

RESULTS

Seven hundred and twenty-four patients were identified with allergic diagnosis, 60% were diagnosed with non-anaphylaxis allergic reactions or unspecified urticaria and 40% with anaphylaxis (n = 286). Annual prevalence of anaphylaxis remained stable over the study period (M = 30.9/10 000 cases, range: 20.8-48.3/10 000). Gender distribution was equal, median age was 9.48 years (interquartile range = 4-15). Most (71%) arrived by private transport. 23% had a prior history of anaphylaxis. Food triggers (44%) were the most common cause of anaphylaxis. Insect bites/stings triggers occurred in 21%. Patients were promptly assessed (average wait time = 13 min), 16% received prior adrenaline injections. Adrenaline was administered in 26% and 20% were admitted to hospital. On discharge, 29% had a follow-up plan, 9% received an allergy clinic referral, 6% anaphylaxis action plan, 26% adrenaline autoinjector prescriptions and allergy testing performed in 6%.

CONCLUSIONS

We found a relatively low prevalence of overall childhood anaphylaxis in a regional area. The two most common causes of anaphylaxis in this population (food and bites/stings) recorded increased prevalence providing an opportunity for further study. Significant gaps in evidence-based care of anaphylaxis were noted, demonstrating the need for improved recognition and treatment guideline implementation in regional areas.

Effect of Nitric Oxide Pathway Inhibition on the Evolution of Anaphylactic Shock in Animal Models: A Systematic Review

Simple Summary

Anaphylactic shock (AS) is the most serious consequence of anaphylaxis, with life-threatening sequelae including hypovolemia, shock, and arrhythmias. The literature lacks evidence for the effectiveness of interventions other than epinephrine in the acute phase of anaphylaxis. Our objective was to assess, through a systematic review, how inhibition of nitric oxide (NO) pathways affects blood pressure, and whether such blockade improves survival in AS animal models. AS was induced in all included studies after or before drug administration that targeted blockade of the NO pathway. In all animal species studied, the induction of AS caused a reduction in arterial blood pressure. However, the results show different responses to the inhibition of nitric oxide pathways. Overall, seven of fourteen studies using inhibition of nitric oxide pathways as pre-treatment before induction of AS showed improvement of survival and/or blood pressure. Four post-treatment studies from eight also showed positive outcomes. This review did not find strong evidence to propose modulation of blockade of the NO/cGMP pathway as a definitive treatment for AS in humans. Well-designed in vivo AS animal pharmacological models are needed to explore the other pathways involved, supporting the concept of pharmacological modulation.

Abstract

Nitric oxide (NO) induces vasodilation in various types of shock. The effect of pharmacological modulation of the NO pathway in anaphylactic shock (AS) remains poorly understood. Our objective was to assess, through a systematic review, whether inhibition of NO pathways (INOP) was beneficial for the prevention and/or treatment of AS. A predesigned protocol for this systematic review was published in PROSPERO (CRD42019132273). A systematic literature search was conducted till March 2022 in the electronic databases PubMed, EMBASE, Scopus, Cochrane and Web of Science. Heterogeneity of the studies did not allow meta-analysis. Nine hundred ninety unique studies were identified. Of 135 studies screened in full text, 17 were included in the review. Among six inhibitors of NO pathways identified, four blocked NO synthase activity and two blocked guanylate cyclase downstream activity. Pre-treatment was used in nine studies and post-treatment in three studies. Five studies included both pre-treatment and post-treatment models. Overall, seven pre-treatment studies from fourteen showed improvement of survival and/or arterial blood pressure. Four post-treatment studies from eight showed positive outcomes. Overall, there was no strong evidence to conclude that isolated blockade of the NO/cGMP pathway is sufficient to prevent or restore anaphylactic hypotension. Further studies are needed to analyze the effect of drug combinations in the treatment of AS.

Adult anaphylaxis: A state-of-the-art review

Anaphylaxis is the most severe among acute allergic diseases and potentially life threatening. Despite its increasing frequency and related burden, it remains often underdiagnosed and improperly managed. Its multisystemic involvement, protean clinical manifestations and its rapid onset are contributory factors. In recent years new acquisitions have shed light into its pathogenesis pathways (and related biomarkers), triggers, factors increasing its severity, along with peculiar clinical manifestations. These breakthrough discoveries have contributed to phenotyping and endotyping this disease, possibly paving the way to a personalized approach which is not available at present. Moreover, to disseminate awareness and standardize diagnostic criteria and management practices, several guidelines and consensus reports, albeit mainly intended for specialist care, have been issued. We here discuss the latest issues in the field of anaphylaxis from the perspective of the emergency and/or internal medicine physician, so to improve its early recognition and treatment in the acute setting and favor allergology referral to implement therapeutical and preventive strategies, such as allergen identification in unclear cases and desensitizing therapies when available (e.g., for Hymenoptera venom allergy).

Development and Validation of the Anaphylaxis Quality of Life Scale for Adults

BACKGROUND

Anaphylaxis is a severe and potentially life-threatening allergic reaction that can have a detrimental impact on quality of life (QoL). There are no validated scales to measure the impact of anaphylaxis on QoL of adults.

OBJECTIVE

The aim of this study was to develop and assess the reliability and validity of a QoL scale for adults with anaphylaxis (Anaphylaxis Quality of Life Scale for Adults [A-QoL-Adults]).

METHODS

All participants were recruited from a specialist allergy clinic and had a confirmed diagnosis of anaphylaxis (as per the World Allergy Organization diagnostic criteria) to food, drugs, venom, or latex or had spontaneous anaphylaxis. Interviews were conducted with 13 adults; data were analyzed using thematic analysis to extract items for a QoL scale. A prototype QoL scale was then completed by 115 participants alongside validated scales to measure generic QoL (World Health Organization Quality of Life Scale [Brief Version] [WHOQoL BREF]), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), and stress (Perceived Stress Scale [PSS]).

RESULTS

The A-QoL-Adults scale has 21 items demonstrating excellent internal reliability (Cronbach α = 0.96). Factor analysis produced 3 subscales: Emotional Impact; Social Impact; and Limitations on Life. Each has excellent internal reliability (0.92, 0.92, and 0.91, respectively). Poorer anaphylaxis-related QoL (total A-QoL-Adults score and subscale scores) correlated significantly with poorer general QoL and greater anxiety, depression, and stress (all P < .01 with medium-to-large effect sizes).

CONCLUSIONS

The A-QoL-Adults scale is a reliable measure of QoL in adults with anaphylaxis and shows good construct validity. It will offer health care professionals a means to further understand the impact of anaphylaxis on adult patients and could help direct and monitor allergy management and the need for further psychological intervention.

Cardiac Arrest Induced by an Anaphylactic Reaction Associated With the First Dose of Cetuximab

Cetuximab is a chimeric mouse-human monoclonal antibody biologic used for the treatment of epidermal growth factor receptor-positive colorectal cancer and head and neck cancer. The incidence of severe anaphylaxis after infusion of cetuximab is a rare but fatal complication. Galactose-α-1,3-galactose (α-gal), a side-chain component in cetuximab, can cause the α-gal syndrome, an allergic cross-reaction to the α-gal contained in mammalian muscle. Here, we report a case of cardiac arrest induced by an anaphylactic reaction from cetuximab infusion. After the initial dosing of cetuximab in an outpatient setting, the patient developed sudden cardiac arrest. Flushing of the skin and bronchoconstriction led to the diagnosis of a severe anaphylactic reaction, whereupon he was treated with repeated doses of epinephrine, steroids, and continuous epinephrine infusion. The patient responded well to initial treatment, leading to a full recovery. The patient’s history and subsequent blood tests did not show any meat allergies. As an increasing number of patients receive chemotherapy as outpatients, it is important to be aware of the possibility of severe allergic reactions induced by these drugs.

Overdiagnosis in the emergency department: a sharper focus

Overdiagnosis occurs when a person's symptoms or life experiences are given a diagnostic label that ultimately causes them more harm than good. We describe the complex drivers of overdiagnosis spanning five interconnected domains, which can lead to numerous negative impacts on patients. Emergency physicians are often tasked with making timely clinical assessments, decisions, and diagnoses that can unintentionally result in overdiagnosis. Three pertinent areas related to overdiagnosis in Emergency Medicine: anaphylaxis, subsegmental pulmonary embolism, and low-risk chest pain are discussed. For a broader perspective, insight on overdiagnosis from medical students and a patient advisor are presented. The perspectives illustrated are meant to spark reflection on: the ethics of labeling a person with a diagnosis, current clinical practices, the limitations of medical education, and patient care and communication in the context of overdiagnosis in the Emergency Department.

Food allergy and hypersensitivity reactions in children and adults-A review

Adverse reactions after food intake are commonly reported and a cause of concern and anxiety that can lead to a very strict diet. The severity of the reaction can vary depending on the type of food and mechanism, and it is not always easy to disentangle different hypersensitivity diagnoses, which sometimes can exist simultaneously. After a carefully taken medical history, hypersensitivity to food can often be ruled out or suspected. The most common type of allergic reaction is immunoglobulin E (IgE)-mediated food allergy (prevalence 5-10%). Symptoms vary from mild itching, stomach pain, and rash to severe anaphylaxis. The definition of IgE-mediated food allergy is allergic symptoms combined with specific IgE-antibodies, and therefore only IgE-antibodies to suspected allergens should be analyzed. Nowadays, methods of molecular allergology can help with the diagnostic process. The most common allergens are milk and egg in infants, peanut and tree nuts in children, and fish and shellfish in adults. In young children, milk/egg allergy has a good chance to remit, making it important to follow up and reintroduce the food when possible. Other diseases triggered by food are non-IgE-mediated food allergy, for example, eosinophilic esophagitis, celiac disease, food protein-induced enterocolitis syndrome, and hypersensitivity to milk and biogenic amines. Some of the food hypersensitivities dominate in childhood, others are more common in adults. Interesting studies are ongoing regarding the possibilities of treating food hypersensitivity, such as through oral immunotherapy. The purpose of this review was to provide an overview of the most common types of food hypersensitivity reactions.

Pilot Project of Special Emergency Medical Service Team for Anaphylaxis in Gangwon-do, Korea: Results from an Online Questionnaire Survey

BACKGROUND

Early recognition and prompt intramuscular epinephrine administration are critical for the treatment of anaphylaxis. The special emergency medical service team (SEMST) is a reorganization plan that incorporates first-level emergency medical technicians (EMTs) and nurses from Korea to give the authority to administer epinephrine. This study evaluates the experience of SEMST and aims to investigate further needs in the pre-hospital management of anaphylaxis.

METHODS

An online survey of 29 questions on the Gangwon-do 119 EMST was conducted. IBM SPSS Statistics ver. 20.0 (IBM Co., Armonk, NY, USA) and R ver.4.0.3. were used for statistical analysis.

RESULTS

A total of 428 (44.6%) participants responded to the questionnaire, and 55.6% (238/428) experienced anaphylaxis. The common presumed cause was insect sting/animal bites at 84.5% (201/238), followed by food (7.6%, 18/238), and drugs (6.3%, 15/238). The frequency of occurrence was highest for tourist attractions (58.6%, 167/285), followed by homes (31.9%, 91/285) and workplace (3.5%, 10/285). Among 136 medical personnel (31.8%) who were currently active or had been active as the SEMST, 95 (70.0%) experienced anaphylaxis, and 58 (61.1%) used epinephrine, which was significantly lower in the non-SEMST group (n = 36, 25.2%). The biggest difficulty in pre-hospital treatment was the limitation of drug administration authority (23.4%, 22/95). The lack of experience and tricky treatment are the chief difficulties in pediatric anaphylaxis. The percentage of correct answers regarding anaphylaxis awareness was significantly higher in the educated (n = 374) than in the non-educated group (n = 54), both for diagnosis (24.9% vs. 11.1%) and treatment (73.5% vs. 37.0%).

CONCLUSION

Proper administration of epinephrine is particularly important for pre-hospital anaphylaxis management in rural areas. Expanding SEMST and conducting periodic education using virtual experiences is necessary.

Managing anaphylaxis in adults

Anaphylaxis is a severe and potentially life-threatening allergic reaction. The recognition and treatment of anaphylaxis remains complex and an area of continued professional development for health professionals. Prompt recognition of anaphylaxis and its subsequent treatment and management by the multidisciplinary team, including nurses and allied health professionals, is key as this increases the patient's chances of survival. Evidence-based clinical information on managing anaphylaxis will enable health professionals to provide safer patient care.

Structure-guided design of ultrapotent disruptive IgE inhibitors to rapidly terminate acute allergic reactions

BACKGROUND

Anaphylaxis represents one of the most severe and fatal forms of allergic reactions. Like most other allergies, it is caused by activation of basophils and mast cells by allergen-mediated cross-linking of IgE bound to its high-affinity receptor, FcεRI, on the cell surface. The systemic release of soluble mediators induces an inflammatory cascade, rapidly causing symptoms with peak severity in minutes to hours after allergen exposure. Primary treatment for anaphylaxis consists of immediate intramuscular administration of adrenaline.

OBJECTIVE

While adrenaline alleviates life-threatening symptoms of an anaphylactic reaction, there are currently no disease-modifying interventions available. We sought to develop potent and fast-acting IgE inhibitors with the potential to rapidly terminate acute allergic reactions.

METHODS

Using affinity maturation by yeast display and structure-guided molecular engineering, we generated 3 optimized disruptive IgE inhibitors based on designed ankyrin repeat proteins and assessed their ability to actively remove IgE from allergic effector cells in vitro as well as in vivo in mice.

RESULTS

The engineered IgE inhibitors rapidly dissociate preformed IgE:FcεRI complexes, terminate IgE-mediated signaling in preactivated human blood basophils in vitro, and shut down preinitiated allergic reactions and anaphylaxis in mice in vivo.

CONCLUSIONS

Fast-acting disruptive IgE inhibitors demonstrate the feasibility of developing kinetically optimized inhibitors for the treatment of anaphylaxis and the rapid desensitization of allergic individuals.

Anaphylaxis and epinephrine autoinjector use in pediatric patients with cutaneous mastocytosis

BACKGROUND/OBJECTIVES

Mastocytosis is a complex disorder presenting with a broad clinical spectrum. In this study, we aimed to evaluate the frequency of systemic symptoms, necessity of the usage of epinephrine autoinjectors (EAI), and factors affecting the use of EAI among pediatric patients with cutaneous mastocytosis (CM).

METHODS

The study population was composed of 53 patients with CM. The clinical data were collected from the medical files. A questionnaire about the patient's anaphylaxis experiences and treatment attitudes toward EAI was performed.

RESULTS

Thirty-three of 53 patients were male (62.3%), and the median age of the study participants was 80 months. Anaphylaxis was reported in two patients (3.7%). One of the patients had drug-induced anaphylaxis, and the other had venom-induced anaphylaxis. Three patients (5.6%) reported a personal history of EAI use due to systemic symptoms. Patients with higher serum tryptase level and cases of familial mastocytosis had more systemic symptoms (P = .012 and P = .010, respectively). The patient rate of compliance with EAI for prescription filling and carrying the EAI was 88.7% and 79.2% respectively. 41.5% of parents were hesitant to use EAI when necessary, although they were trained for the use of it by medical staff.

CONCLUSIONS

The rate of anaphylaxis in patients with CM in the current study wassignificant and justifies prescribing EAI. Detailed education and counseling on EAI usage are needed to reduce parental hesitancy.

ICD-10 anaphylaxis algorithm and the estimate of vaccine-attributable anaphylaxis incidence in Medicare

BACKGROUND

Anaphylaxis is a rare, serious allergic reaction. Its identification in large healthcare databases can help better characterize this risk.

OBJECTIVE

To create an ICD-10 anaphylaxis algorithm, estimate its positive predictive values (PPVs) in a post-vaccination risk window, and estimate vaccination-attributable anaphylaxis rates in the Medicare Fee For Service (FFS) population.

METHODS

An anaphylaxis algorithm with core and extended portions was constructed analyzing ICD-10 anaphylaxis claims data in Medicare FFS from 2015 to 2017. Cases of post-vaccination anaphylaxis among Medicare FFS beneficiaries were then identified from October 1, 2015 to February 28, 2019 utilizing vaccine relevant anaphylaxis ICD-10 codes. Information from medical records was used to determine true anaphylaxis cases based on the Brighton Collaboration's anaphylaxis case definition. PPVs were estimated for incident anaphylaxis and the subset of vaccine-attributable anaphylaxis within a 2-day post-vaccination risk window. Vaccine-attributable anaphylaxis rates in Medicare FFS were also estimated.

RESULTS

The study recorded 66,572,128 vaccinations among 21,685,119 unique Medicare FFS beneficiaries. The algorithm identified a total of 190 suspected anaphylaxis cases within the 2-day post-vaccination window; of these 117 (62%) satisfied the core algorithm, and 73 (38%) additional cases satisfied the extended algorithm. The core algorithm's PPV was 66% (95% CI [56%, 76%]) for identifying incident anaphylaxis and 44% (95% CI [34%, 56%]) for vaccine-attributable anaphylaxis. The vaccine-attributable anaphylaxis incidence rate after any vaccination was 0.88 per million doses (95% CI [0.67, 1.16]).

CONCLUSION

The ICD-10 claims algorithm for anaphylaxis allows the assessment of anaphylaxis risk in real-world data. The algorithm revealed vaccine-attributable anaphylaxis is rare among vaccinated Medicare FFS beneficiaries.

ANAPHYLAXIS AND PREGNANCY: A SYSTEMATIC REVIEW AND CALL FOR PUBLIC HEALTH ACTIONS

BACKGROUND

Although rare, anaphylaxis during pregnancy implies a risk to both mothers and newborns.

OBJECTIVE

This systematic review is intended to identify key issues in the diagnosis and management of this condition in order to support prevention strategies and decrease the risk of death related to anaphylaxis during pregnancy.

METHODS

We searched MEDLINE, Cochrane, Lilacs, Scielo and Science Direct databases for manuscripts concerning terms "anaphylaxis during pregnancy" without language restrictions. We screened studies, extracted data, and assessed risk of bias independently in duplicate.

RESULTS

We selected 12 articles. Frequency of anaphylaxis during pregnancy is estimated between 1.5 to 3.8 per 100 000 maternities. Only one study provided anaphylaxis mortality data in pregnant women, and the rate of anaphylaxis-related maternal mortality is estimated at 0.05 per 100 000 live births. No standard definition of anaphylaxis severity has been utilized. Forty-nine percent to 74% of anaphylaxis cases were described during caesarean sections. Beta-lactam antibiotics (58%), latex (25%) and anaesthetic agents (17%) were the main culprits. In 17% of papers, causative agents were proven by allergy testing. Seventy two percent of articles proposed the same management and treatment for a clinical episode of anaphylaxis during pregnancy as in non-pregnant patients, and, use of epinephrine in the patient's care during anaphylaxis in pregnancy.

CONCLUSION

Few studies address anaphylaxis during pregnancy, and the majority have been produced by non-allergy specialists. Collaboration between different specialists involved in the care of pregnant women should be established in order to support preventive strategies and reduce avoidable deaths.

Does Informal Education Training Increase Awareness of Anaphylaxis among Students of Medicine? Before-After Survey Study

Allergies are among the most common chronic diseases in Europe. The most serious complication is anaphylactic shock. Most cases occur outside the hospital; thus, knowledge of symptoms and first aid is crucial. This study aimed to evaluate the awareness of anaphylaxis and the ability to use adrenaline auto-injectors among medical students, and to determine an improvement after training based on non-formal education. The research was conducted among 364 medicine students (years 1–5) from the Medical University of Gdańsk, with year-specific curriculum-based general medical knowledge. Training consisted of pre-test, practical training and post-test. Descriptive statistics were used to reveal the characteristics of students from different grades. A Mann–Whitney U test was used for statistical analysis. The tested students did not have sufficient knowledge to provide first aid in cases of anaphylaxis before training. There was an increase in knowledge (on average, 28.6%, p = 0.005) after training. Almost all (99.4%) of the respondents believed that they would be able to use an adrenaline auto-injector in case of emergency after the training. The training based on non-formal education was effective. The use of the subject-performed task method helped students to remember the stages of action in stressful situations.

ARIA-EAACI statement on severe allergic reactions to COVID-19 vaccines - An EAACI-ARIA Position Paper

Further to the approval of the Coronavirus disease 2019 (COVID-19) vaccine BNT162b2, several severe anaphylaxis cases occured within the first few days of public vaccination. An investigation is taking place to understand the cases and their triggers. The vaccine will be administered to a large number of individuals worldwide and there are raising concerns that severe adverse events might occur. With the current information, the European Academy of Allergy and Clinical Immunology (EAACI) states its position for the following preliminary recommendations that are to be revised as soon as more data emerge. To minimize the risk of severe allergic reactions in vaccinated individuals, it is urgently required to understand the specific nature of the reported severe allergic reactions, including the background medical history of the individuals affected and the mechanisms involved. To achieve this goal, all clinical and laboratory information should be collected and reported. Mild and moderate allergic patients should not be excluded from the vaccine as this could have a significant impact on reaching the goal of population immunity. Healthcare practitioners vaccinating against COVID-19 are required to be sufficiently prepared to recognize and treat anaphylaxis properly with the ability to administer adrenaline. Further to vaccine administration, a mandatory observation period of at least 15 minutes should be followed for all individuals. The current data have not shown any higher risk for patients suffering from allergic rhinitis or asthma, and this message should be clearly stated by physicians to enable our patients to trust the vaccine. More than 30% of the population suffers from allergic diseases and the benefit of the vaccination clearly outweighs the risk of severe COVID-19 development.

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.

Real-world effectiveness of mepolizumab in patients with severe asthma and associated comorbidities

BACKGROUND

Patients with severe asthma frequently have associated comorbidities, which can compound existing symptoms, complicating asthma management.

OBJECTIVE

To describe the real-world effectiveness of mepolizumab in patients with severe asthma stratified by common overlapping comorbidities.

METHODS

This was a retrospective analysis of patients with asthma from the MarketScan Commercial and Medicare Supplemental Database initiating mepolizumab treatment (index date). Eligible patients had more than or equal to 1 claim (excluding claims for diagnostic tests) with a diagnosis code for more than or equal to 1 of 7 comorbidities (atopic disease, nasal polyps, chronic sinusitis, obesity, respiratory infections, chronic obstructive pulmonary disease, and depression/anxiety) during the 12-month preindex baseline period; these were used to stratify patients into 7 nonmutually exclusive subgroups. Outcomes included asthma exacerbations and exacerbation-related health care resource utilization during the 12-month baseline and follow-up periods. Each patient acted as their own control.

RESULTS

Of the 639 patients included, the most common comorbidities were atopic diseases (73.2%), respiratory infections (55.6%), and chronic sinusitis (45.1%). Across all 7 comorbidity subgroups, there were significant (P < .05) reductions of 38% to 55% and 57% to 83% in exacerbations and exacerbations requiring hospitalization, respectively, during the follow-up vs baseline period, except for exacerbations requiring hospitalization in the nasal polyp subgroup, owing to the small subgroup sample size. During the follow-up vs baseline periods, mean number of oral corticosteroids claims was significantly (P < .001) reduced by 29% to 38%; 39% to 47% of patients achieved greater than or equal to 50% oral corticosteroids dose reduction. Significant reductions in exacerbation-related health care resource utilization were also observed.

CONCLUSION

Mepolizumab treatment provided real-world clinical benefits in patients.

Sodium R-lipoate and enzymatically-modified isoquercitrin suppressed IgE-independent anaphylactic reactions and stress-induced gastric ulceration in mice

Anaphylaxis is a life-threatening allergic reaction, for which the worldwide prevalence is rapidly increasing. The currently used synthetic antiallergic drugs have a high tendency to cause adverse effects, like gastric ulcers, in long-term use. Therefore, a great deal of attention has been given to develop new safer and more effective antiallergic agents from natural compounds that are chemically/enzymatically-modified. Here, we evaluated/compared the efficacy of two different doses (50 and 100 mg/kg body weight "b.w", given orally) of sodium R-lipoate (NaRLA) and enzymatically-modified isoquercitrin (EMIQ) in alleviating both local/systemic non-immunological anaphylactic reactions and stress-induced gastric ulceration in mice, in comparison with sulfasalazine (SSZ) as a reference drug. The results indicated that the pre-treatment of animals with NaRLA or EMIQ (especially at 100 mg/kg b.w) completely succeeded, as SSZ, in alleviating the hind paw edema induced by either histamine or compound 48/80 (Cpd 48/80). Furthermore, NaRLA and EMIQ prevented the mast cell degranulation and anaphylactic shock caused by Cpd 48/80 (in a dose-dependent manner) and reduced significantly (P < 0.001) the histamine release from the mouse peritoneal mast cells, like SSZ. Moreover, their use was associated with alleviating both gastric histopathological and biochemical alterations in the water-restraint stress (WRS) mice model towards the control values. They also decreased the percentage of degranulated mesenteric mast cells in the WRS mice model. In conclusion, our findings provide possibility that both NaRLA and EMIQ may serve as an effective therapeutic agents for mast cells-dependent anaphylactic reactions without risks of inducing gastric ulcers.

Retrieval of Additional Epinephrine from Adrenaclick-Style Epinephrine Autoinjectors

Anaphylaxis is a life-threatening allergic reaction involving multiple organ systems that can result in significant morbidity and mortality if left untreated. Epinephrine is the mainstay of treatment. Most episodes of anaphylaxis resolve after a single dose of epinephrine, but biphasic and protracted courses of anaphylaxis are well described. The need for additional doses of epinephrine poses a significant challenge in the wilderness setting, because patients and providers may only carry a single autoinjector. Prior work has demonstrated successful disassembly of various brands of epinephrine autoinjectors to retrieve additional drug product for repeat dosing. We describe 2 techniques to retrieve additional doses of epinephrine from Adrenaclick-style epinephrine autoinjectors. The techniques described are off-label and are not approved by the manufacturer or the Food and Drug Administration. Wilderness providers should familiarize themselves with techniques for retrieval of additional epinephrine from various autoinjectors in light of significant differences in product design.

Who Is Really at Risk for Anaphylaxis Due to COVID-19 Vaccine?

The vaccination campaign against the Severe acute respiratory syndrome coronavirus 2 (Sars-Cov-2) started on 8 December 2020 in UK, after the approval of BNT162b2 by the Healthcare products Regulatory Agency (MHRA) [...].