Anaphylaxis

Anaphylaxis: first clinical presentation, subsequent referral practise, and suspected elicitor-an observational study

Anaphylaxis is an allergic manifestation characterised by rapid onset and progression. Rapid treatment may be challenging in patients with atypical symptoms or no previous history of anaphylaxis. This study aimed to describe the clinical prehospital presentation of first-time anaphylactic patients. To help target educational initiatives, we sought to identify which groups of medical professionals are most likely to encounter first-time anaphylactic patients and investigated the referral pattern for suspected anaphylactic patients for specialised treatment. A retrospective register-based study from the Region of Southern Denmark. Patients referred to the Allergy Centre, Odense University Hospital, from 2019 to 2021 were included. The medical records were manually reviewed for first contact with the emergency departments or the emergency medical service. 444 patients with suspected anaphylaxis were referred. 226 patients had grade 3-5 systemic allergic reactions as classified by the World Allergy Organisation; 90% had cutaneous symptoms, 63% symptoms from the central nervous system, 42% gastrointestinal symptoms, 40% cardiovascular symptoms, 36% had upper-airway symptoms, and 36% had lower-airway symptoms. Patients treated prehospitally had a significantly more severe degree of anaphylaxis than patients only treated within the hospital. More than half of the patients with suspected anaphylaxis were referred to the Allergy Centre from the emergency departments. Patients with allergies progressing to severe anaphylaxis most often are treated prehospitally before transport to emergency departments. From the emergency departments, they are referred to the allergy centre. Education concerning the immediate treatment of severe anaphylaxis should primarily be targeted towards prehospital care providers.

Prevention of Anaphylaxis Episodes in Idiopathic Anaphylaxis by Omalizumab

INTRODUCTION

In 15-35 percent of patients with anaphylaxis, the triggering allergen cannot be found; therefore, a diagnosis of idiopathic anaphylaxis (IA) is made. We report on the outcomes in patients with IA treated with omalizumab.

METHODS

We included consequent omalizumab-treated IA adult patients treated with omalizumab 300 mg every 4 weeks.

RESULTS

Out of 7 patients, 6 were female, median age 40 years with the frequency of anaphylaxis episodes from 3 in 2 years to 5 in 4 months. Baseline tryptase ranged from 1.71 to 12.0 μg/L. An increase in tryptase during anaphylaxis was documented in 6 patients. Activating KIT p.D816V variant was detected in 2 patients. One patient also had hereditary alpha-tryptasemia (HαT). The duration of omalizumab treatment was 0.5-7.5 years. None of the patients have experienced an anaphylactic reaction since the start of treatment. Mild systemic reactions were reported in 6 patients (86%). The presence of underlying cMCD had no impact on the treatment outcome.

CONCLUSION

All patients in our study had complete responses to omalizumab. The presence of KIT p.D816V and HαT did not influence the response to omalizumab treatment.

Prehospital and In-Hospital Treatment with Adrenaline and Related Prognosis in Anaphylaxis Patients

INTRODUCTION

Although intramuscular adrenaline is the recommended first-line treatment for anaphylaxis, not all patients receive this treatment. The consequences in daily clinical practice are sparsely described. This study aimed to investigate the treatment administered to anaphylactic patients and the related prognosis.

METHODS

A retrospective register-based study of patients with anaphylaxis referred to the allergy centre, Odense University Hospital (2019-2021). Each patient's medical records were reviewed for contacts with the emergency departments and the prehospital emergency medical service in the Region of Southern Denmark. The World Allergy Organization (WAO) grading system was used to assess the severity of prehospital and in-hospital anaphylaxis. Furthermore, the treatment administered to the patients was registered.

RESULTS

In total, 315 patients were included. The prehospital system had contact with 256 of these patients (two were released prehospitally following treatment and 12 patients had insufficient data to assess anaphylaxis). Of the remaining 242 patients, 115 had anaphylaxis prehospitally (WAO grades 3-5); 59% (67/115) received adrenaline. Among the 67 patients who received prehospital adrenaline, 9 patients (13.4%; 95% CI: 6.3-24.0%) still had anaphylaxis at arrival at the emergency department. Of the 48 patients that were not treated with prehospital adrenaline, 17 patients (35.5%; 95% CI: 22.1-50.5) had anaphylaxis at the arrival to the emergency department. Among the 127 patients without prehospital anaphylaxis (WAO grades 0-2), 22 patients (18.2%; 95% CI: 11.8-26.2%) who did not receive prehospital adrenaline had anaphylaxis at arrival to the emergency department, while none of the 6 patients treated prehospitally with adrenaline had anaphylaxis.

CONCLUSION

Omission of prehospital adrenaline in anaphylactic patients is associated with more severe anaphylactic symptoms at arrival to the hospital. Adrenaline treatment remains suboptimal since only half of the patients received prehospital adrenaline and only 1 out of 4 patients, with clinical signs of anaphylaxis, received adrenaline inside the hospital.

Navigating Food Allergies: Advances in Diagnosis and Treatment Strategies

Food allergy is a major health concern worldwide, encompassing both immunologic and non-immunologic reactions. This review thoroughly examines the pathophysiology, clinical manifestations, and treatment options for various types of food allergies. Immunologic food allergies, including IgE-mediated reactions such as oral allergy syndrome and systemic anaphylaxis, pose various diagnostic and management challenges. Non-IgE-mediated reactions such as food protein-induced enterocolitis syndrome, dermatitis herpetiformis, and proctocolitis necessitate individualized patient care. In addition, mixed reactions such as eosinophilic esophagitis and atopic dermatitis complicate the clinical picture. Skin prick tests, serum-specific IgE tests, and oral food challenges are all necessary for accurate food allergy diagnosis. The primary therapeutic options are allergen avoidance, epinephrine-based emergency management, and emerging treatments like immunotherapy. Our review emphasizes the importance of multidisciplinary collaboration and ongoing research in improving our understanding and managing food allergies, promising a brighter future for those affected.

Hymenoptera Venom Immunotherapy Meets Factitious Disorder

Factitious disorder on self is a psychiatric disorder in which individuals fabricate or induce signs or symptoms of a disease. Factitious anaphylaxis, with symptoms suggestive of a life-threatening allergic reaction, is extremely rare. Several cases of factitious disorder reactions during allergen immunotherapy for airborne allergens have been reported. We report the case of a young female patient who presented factitious anaphylaxis during venom immunotherapy to vespid venom extract. Symptoms of stridor, dyspnea, coughing and loss of consciousness were observed during the built-up phase of venom immunotherapy, mimicking allergic reactions to the venom extracts. Diagnosis of factitious disorder prompted the discontinuation of venom immunotherapy.

Health-related quality of life in food and venom induced anaphylaxis and role of influencing factors

The impact on health-related quality of life (HRQL) plays a key role for patients suffering from allergies and anaphylaxis. In this narrative review we review the HRQL in allergic patients suffering from food and venom allergy, both being the most frequent elicitors of severe allergic, potential life-threatening reactions and provide an overview on the current knowledge and identified gaps. The data show that for food and venom allergy standardized assessment tools to measure HRQL are available and have been successfully applied. Our analysis shows that multiple factors can modulate HRQL in these patient groups. These include sociodemographic data like patients' age and sex, fear of accidental reactions but also external factors like the social environment and the appreciation of the seriousness of the condition by others. External factors may have a significant impact on HRQL and should be considered in patient-related outcome assessments to avoid biased measurements possibly affecting the results. The assessment of the quality of life in the context of specific immunotherapy should consider lifestyle factors and ideally, the individual change in HRQL should be measured. Although there are many data indicating a negative impact on HRQL in food allergic children and their caregivers, limited data are existing from adults with food allergy and venom allergic patients from all age groups. Also, the use of standardized questionnaires should be extended to allow for a better comparability of results between studies. Therefore, translation to additional languages is necessary. Taken together, the eliciting allergen, the severity of the allergic disease but moreover multiple external factors impact the outcome in HRQL and should be considered in HRQL assessment.

The impact of type 2 immunity and allergic diseases in atherosclerosis

Allergic diseases are allergen-induced immunological disorders characterized by the development of type 2 immunity and IgE responses. The prevalence of allergic diseases has been on the rise alike cardiovascular disease (CVD), which affects arteries of different organs such as the heart, the kidney and the brain. The underlying cause of CVD is often atherosclerosis, a disease distinguished by endothelial dysfunction, fibrofatty material accumulation in the intima of the artery wall, smooth muscle cell proliferation, and Th1 inflammation. The opposed T-cell identity of allergy and atherosclerosis implies an atheroprotective role for Th2 cells by counteracting Th1 responses. Yet, the clinical association between allergic disease and CVD argues against it. Within, we review different phases of allergic pathology, basic immunological mechanisms of atherosclerosis and the clinical association between allergic diseases (particularly asthma, atopic dermatitis, allergic rhinitis and food allergy) and CVD. Then, we discuss putative atherogenic mechanisms of type 2 immunity and allergic inflammation including acute allergic reactions (IgE, IgG1, mast cells, macrophages and allergic mediators such as vasoactive components, growth factors and those derived from the complement, contact and coagulation systems) and late phase inflammation (Th2 cells, eosinophils, type 2 innate-like lymphoid cells, alarmins, IL-4, IL-5, IL-9, IL-13 and IL-17).

Lipid transfer protein syndrome: How to save a life through careful education

Introduction

Lipid transfer proteins (nsLTPs) are ubiquitous allergens. Patients affected by nsLTP syndrome experience symptoms to various plant-derived foods, ranging from local manifestations to anaphylaxis, the critical treatment of which is represented by self-administration of adrenaline. The principle aim of this study is to assess how dietary recommendations influence the occurrence of new and severe cases and if poly-sensitization to different nsLTPs may play a role. We also investigated about the appropriate use of adrenaline auto-injector during the episodes of anaphylaxis. Moreover, we examinated how other features (ie, co-sensitization to profilin and PR-10 and the presence of risk co-factors) affect these events.

Materials and methods

We evaluated 78 patients allergic to nsLTPs, investigating adherence to diet and ability to use the adrenaline auto-injector. Number of sensitization to nsLTPs, co-sensitization to other panallergens, and presence of risk factors for new reactions were also assessed. Diagnosis was based on clinical history and positivity to in vivo and in vitro tests. During the follow-up, compliance, diet modifications, and new reactions were noted, and re-training for the use of epinephrine auto-injector was performed. At the last visit we evaluated the patients’ ability to use the self-injector.

Results

The whole of fruits belonging to the Rosaceae family emerged as the most frequent culprit foods (28%), followed by walnut (17%), peanut (17%), and hazelnut (10%). At the baseline visit 23% of the patients described the presence of a risk factor during the allergic reaction (mainly nonsteroidal anti-inflammatory drugs [NSAIDs] and exercise). Forty-five percent of the patients reported anaphylactic reactions; no association between the type of food and the severity of the reactions was found. The presence of sensitization to 4 or more nsLTPs was associated to more severe reactions (p < .05; OR 1.67). During the follow-up 38% of the patients experienced at least 1 new allergic reaction: in 79% of them the culprit food was previously tolerated, and in 69% the reaction was an anaphylaxis. Only 47% of the patients showed a proper use of adrenaline auto-injector during the final evaluation, but a significant correlation between periodic education and reduction of the probability of mistakes in the use was reported (p < .05; OR 0.34). Furthermore, an association between co-sensitization to PR-10 (in particular Bet v1) and profilin and less severe symptoms was found, but without a significant odds ratio.

Conclusion

A careful education aimed to the prevention of new reactions, through dietary restrictions and avoidance of risk co-factors, and to the management of anaphylaxis, through the training for the correct use of adrenaline auto-injector, should be a routine practice in nsLTP syndrome.

State-of-the-Art on Biomarkers for Anaphylaxis in Obstetrics

Anaphylaxis is an unpredictable systemic hypersensitivity reaction and constitutes a high risk of maternal and fetal morbidity and mortality when occurring during pregnancy. Currently, the acute management of anaphylaxis is based on clinical parameters. A total serum tryptase is only used to support an accurate diagnosis. There is a need to detect other biomarkers to further assess high-risk patients in obstetrics. Our objective is to present biomarkers in this complex interdisciplinary approach beyond obstetrician and anaesthetic management. Candidate biomarkers derive either from mediators involved in immunopathogenesis or upcoming molecules from systems biology and proteomics. Serum tryptase is determined by singleplex immunoassay method and is important in the evaluation of anaphylactic mast cell degranulation but also in the assessment of other risk factors for anaphylaxis such as systemic mastocytosis. Another category of biomarkers investigates the IgE-mediated sensitization to triggers potentially involved in the etiology of anaphylaxis in pregnant women, using singleplex or multiplex immunoassays. These in vitro tests with natural extracts from foods, venoms, latex or drugs, as well as with molecular allergen components, are useful because in vivo allergy tests cannot be performed on pregnant women in such a major medical emergency due to their additional potential risk of anaphylaxis.

Proteomic and Biological Analysis of an In Vitro Human Endothelial System in Response to Drug Anaphylaxis

Anaphylaxis is a life-threatening systemic hypersensitivity reaction. During anaphylaxis, mediator release by effector cells causes endothelial barrier breakdown, increasing vascular permeability and leakage of fluids, which may lead to tissue edema. Although endothelial cells (ECs) are key players in this context, scant attention has been paid to the molecular analysis of the vascular system, and further analyses of this cell type are necessary, especially in humans. The protein expression pattern of human microvascular ECs was analyzed in response to sera from anaphylactic patients (EC-anaphylaxis) and sera from non-allergic subjects (EC-control) after 2 hours of contact. Firstly, a differential quantitative proteomic analysis of the protein extracts was performed by mass spectrometry using an isobaric labeling method. Second, the coordinated behavior of the identified proteins was analyzed using systems biology analysis (SBA). The proteome of the EC-anaphylaxis system showed 7,707 proteins, of which 1,069 were found to be significantly altered between the EC-control and EC-anaphylaxis groups (p-value < 0.05). Among them, a subproteome of 47 proteins presented a high rate of change (|ΔZq| ≥ 3). This panel offers an endothelial snapshot of the anaphylactic reaction. Those proteins with the highest individual changes in abundance were hemoglobin subunits and structural support proteins. The interacting network analysis of this altered subproteome revealed that the coagulation and complement systems are the main biological processes altered in the EC-anaphylactic system. The comprehensive SBA resulted in 5,512 functional subcategories (biological processes), 57 of which were significantly altered between EC-control and EC-anaphylaxis. The complement system, once again, was observed as the main process altered in the EC system created with serum from anaphylactic patients. Findings of the current study further our understanding of the underlying pathophysiological mechanisms operating in anaphylactic reactions. New target proteins and relevant signaling pathways operating in the in vitro endothelial-serum system have been identified. Interestingly, our results offer a protein overview of the micro-EC-anaphylaxis environment. The relevance of the coagulation, fibrinolytic, contact and complement systems in human anaphylaxis is described. Additionally, the untargeted high-throughput analysis used here is a novel approach that reveals new pathways in the study of the endothelial niche in anaphylaxis.

Vaccines and allergic reactions: The past, the current COVID-19 pandemic, and future perspectives

Vaccines are essential public health tools with a favorable safety profile and prophylactic effectiveness that have historically played significant roles in reducing infectious disease burden in populations, when the majority of individuals are vaccinated. The COVID-19 vaccines are expected to have similar positive impacts on health across the globe. While serious allergic reactions to vaccines are rare, their underlying mechanisms and implications for clinical management should be considered to provide individuals with the safest care possible. In this review, we provide an overview of different types of allergic adverse reactions that can potentially occur after vaccination and individual vaccine components capable of causing the allergic adverse reactions. We present the incidence of allergic adverse reactions during clinical studies and through post-authorization and post-marketing surveillance and provide plausible causes of these reactions based on potential allergenic components present in several common vaccines. Additionally, we review implications for individual diagnosis and management and vaccine manufacturing overall. Finally, we suggest areas for future research.

Revisiting the role of MRGPRX2 on hypersensitivity reactions to neuromuscular blocking drugs

Anaphylaxis is caused by a variety of triggers including Food and Drug Administration (FDA)-approved antibiotics, contrast media and neuromuscular blocking drugs (NMBDs). Traditionally, drug-induced anaphylaxis was thought to result mainly from IgE-mediated histamine release from mast cells. Recently, a G protein-coupled receptor known as MRGPRX2 has been identified and shown to be highly expressed on human skin but not lung mast cells. The demonstration that many NMBDs induce degranulation in human mast cells via MRGPRX2 led to the idea that this receptor contributes to NMBD-induced hypersensitivity reactions. However, other studies have raised doubts regarding its role in drug-induced hypersensitivity. This review discusses the current status and controversy on MRGPRX2's role on NMBD-induced hypersensitivity.

Management of anaphylaxis due to COVID-19 vaccines in the elderly

Older adults, especially men and/or those with diabetes, hypertension, and/or obesity, are prone to severe COVID‐19. In some countries, older adults, particularly those residing in nursing homes, have been prioritized to receive COVID‐19 vaccines due to high risk of death. In very rare instances, the COVID‐19 vaccines can induce anaphylaxis, and the management of anaphylaxis in older people should be considered carefully. An ARIA‐EAACI‐EuGMS (Allergic Rhinitis and its Impact on Asthma, European Academy of Allergy and Clinical Immunology, and European Geriatric Medicine Society) Working Group has proposed some recommendations for older adults receiving the COVID‐19 vaccines. Anaphylaxis to COVID‐19 vaccines is extremely rare (from 1 per 100,000 to 5 per million injections). Symptoms are similar in younger and older adults but they tend to be more severe in the older patients. Adrenaline is the mainstay treatment and should be readily available. A flowchart is proposed to manage anaphylaxis in the older patients.