Idiopathic anaphylaxis

Test Panel of Hidden Allergens for "Idiopathic Anaphylaxis" Reveals Wheat Allergy Dependent on Augmentation Factors as Common Final Diagnosis

BACKGROUND

Idiopathic anaphylaxis (IA) is an unresolved concern. Hidden allergens may be relevant in IA and in nonsteroidal anti-inflammatory drug hypersensitivity (NSAID-HS).

OBJECTIVE

To identify hidden elicitors for IA and NSAID-HS by a skin prick test (SPT) (13 allergens) and allergen-specific IgE (sIgE) panel (12 allergens) and to determine the value of each tested allergen.

METHODS

We retrospectively included all patients from 2018 to 2021 referred with a suspicion of IA or NSAID-HS by history in whom SPT and/or sIgE to allergens of the IA panel were performed. Patient characteristics from patients' records included comorbidities, history and symptoms of anaphylaxis, serum baseline tryptase level, total IgE level, SPT, sIgE, challenge results, and final diagnoses.

RESULTS

A total of 134 patients (77 female, mean age 39.7 ± 14.6 years) were included. Median serum baseline tryptase and total IgE levels were 4.23 μg/L and 133.5 kU/L, respectively. Allergologic workup with the IA panel resulted in positive SPT and sIgE in 61 (47%) and 66 (60%) patients, respectively. In those, confirmation or exclusion of allergy, mostly by challenge, led to a definitive diagnosis in 61 of 134 patients (46%). Skin prick test was most frequently positive to gluten (22.4%) and sIgE to ω5-gliadin (21.6%), which correlated with the history (r = 0.310, P < .001; and r = 0.407, P < .001, respectively). In 28 of 134 patients (21%) with initially suspected IA or NSAID-HS, challenges confirmed occult food allergy in which wheat allergy dependent on augmentation factors was the most frequent cause of anaphylaxis (19%).

CONCLUSIONS

Wheat allergy dependent on augmentation factors should be considered in all patients with anaphylaxis of unknown cause or after NSAID intake.

Pediatric idiopathic anaphylaxis: practical management from infants to adolescents

Idiopathic anaphylaxis (IA) remains a frustrating challenge for both patients and physicians. The aim of this paper is to focus on IA in pediatric ages and suggest possible diagnostic algorithms according to specific age ranges (infants, children, and adolescents). In fact, in a variable percentage of patients, despite extensive diagnostic tests, the cause of anaphylactic episodes cannot be identified. Moreover, the lack of a unanimous IA definition requires a careful and detailed diagnostic workup. Prompt recognition of signs and symptoms, especially in younger children, and an accurate clinical history often allow a choice of the most appropriate diagnostic tests and a correct differential diagnosis.

Oxidative Stress and Mitochondria Are Involved in Anaphylaxis and Mast Cell Degranulation: A Systematic Review

Anaphylaxis, an allergic reaction caused by the massive release of active mediators, can lead to anaphylactic shock (AS), the most severe and potentially life-threatening form of anaphylactic reaction. Nevertheless, understanding of its pathophysiology to support new therapies still needs to be improved. We performed a systematic review, assessing the role and the complex cellular interplay of mitochondria and oxidative stress during anaphylaxis, mast cell metabolism and degranulation. After presenting the main characteristics of anaphylaxis, the oxidant/antioxidant balance and mitochondrial functions, we focused this review on the involvement of mitochondria and oxidative stress in anaphylaxis. Then, we discussed the role of oxidative stress and mitochondria following mast cell stimulation by allergens, leading to degranulation, in order to further elucidate mechanistic pathways. Finally, we considered potential therapeutic interventions implementing these findings for the treatment of anaphylaxis. Experimental studies evaluated mainly cardiomyocyte metabolism during AS. Cardiac dysfunction was associated with left ventricle mitochondrial impairment and lipid peroxidation. Studies evaluating in vitro mast cell degranulation, following Immunoglobulin E (IgE) or non-IgE stimulation, revealed that mitochondrial respiratory complex integrity and membrane potential are crucial for mast cell degranulation. Antigen stimulation raises reactive oxygen species (ROS) production from nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and mitochondria, leading to mast cell degranulation. Moreover, mast cell activation involved mitochondrial morphological changes and mitochondrial translocation to the cell surface near exocytosis sites. Interestingly, antioxidant administration reduced degranulation by lowering ROS levels. Altogether, these results highlight the crucial role of oxidative stress and mitochondria during anaphylaxis and mast cell degranulation. New therapeutics against anaphylaxis should probably target oxidative stress and mitochondria, in order to decrease anaphylaxis-induced systemic and major organ deleterious effects.

Anaphylaxis in a Swiss university emergency department: clinical characteristics and supposed triggers

BACKGROUND

Anaphylaxis is the most severe form of acute systemic and potentially life-threatening reactions triggered by mast and basophilic cells. Recent studies show a worldwide incidence between 50 and 112 occurrences per 100,000 person-years. The most identified triggers are food, medications, and insect venoms. We aimed to analyze triggers and clinical symptoms of patients presenting to a Swiss university emergency department for adults.

METHODS

Six-year retrospective analysis (01/2013 to 12/2018) of all patients (> 16 years of age) admitted with moderate or severe anaphylaxis (classification of Ring and Messmer ≥ 2) to the emergency department. Patient and clinical data were extracted from the electronic medical database of the emergency department.

RESULTS

Of the 531 includes patients, 53.3% were female, the median age was 38 [IQR 26-51] years. The most common suspected triggers were medications (31.8%), food (25.6%), and insect stings (17.1%). Organ manifestations varied among the different suspected triggers: for medications, 90.5% of the patients had skin symptoms, followed by respiratory (62.7%), cardiovascular (44.4%) and gastrointestinal symptoms (33.7%); for food, gastrointestinal symptoms (39.7%) were more frequent than cardiovascular symptoms (36.8%) and for insect stings cardiovascular symptoms were apparent in 63.8% of the cases.

CONCLUSIONS

Average annual incidence of moderate to severe anaphylaxis during the 6-year period in subjects > 16 years of age was 10.67 per 100,000 inhabitants. Medications (antibiotics, NSAID and radiocontrast agents) were the most frequently suspected triggers. Anaphylaxis due to insect stings was more frequently than in other studies. Regarding clinical symptoms, gastrointestinal symptoms need to be better considered, especially that initial treatment with epinephrine is not delayed.

Meta-analysis of the adoption of omalizumab in the treatment of pediatric allergic diseases

Introduction

Allergic diseases are common chronic conditions in children, omalizumab has a wide range of adoptions in various diseases. A meta-analysis was implemented to demonstrate the efficacy of omalizumab in the therapy of pediatric allergic diseases.

Materials and methods

English databases were searched. The search terms included "Omalizumab", "Children", "Allergic asthma", and "Atopic dermatitis". The literature was screened regarding inclusion and exclusion criteria, and data were extracted and analyzed using RevMan5.3.

Results

a total of six suitable studies, comprising 2761 patients, were selected for inclusion. The meta-analysis results implied that at 24 weeks, OR for worsening of symptoms in children was 0.10 (95 % confidence interval [CI] 0.03-0.41), Z = 3.24, P = 0.001 (P < 0.05); at 52 weeks, OR was 0.27 (95 % CI 0.09-0.83), Z = 2.28, P = 0.02 (P < 0.05); and during treatment, OR for adverse events in children was 0.87 (95 % CI 0.60-1.29), Z = 0.68, P = 0.49 (P > 0.05).

Conclusion

the study comprised six investigations that examined the effectiveness of omalizumab in treating pediatric allergic diseases. The findings demonstrated that, in comparison to standard treatment, omalizumab can greatly alleviate allergy-related clinical symptoms in children, slow down disease progression, and has a higher safety profile with fewer adverse reactions. These results have practical implications and highlight the potential value of omalizumab in pediatric allergy treatment.

Combination of H1 and H2 Histamine Receptor Antagonists: Current Knowledge and Perspectives of a Classic Treatment Strategy

Histamine receptor antagonists, which can bind to specific histamine receptors on target cells, exhibit substantial therapeutic efficacy in managing a variety of histamine-mediated disorders. Notably, histamine H1 and H2 receptor antagonists have been extensively investigated and universally acknowledged as recommended treatment agents for numerous allergic diseases and acid-related disorders, respectively. Historically, the combination of H1 and H2 receptor antagonists has been considered a classic treatment strategy, demonstrating relatively superior efficacy compared with single-drug therapies in the treatment of diverse histamine-mediated diseases. The latest emerging studies have additionally suggested the underlying roles of histamine and H1R and H2R in the development of anxiety disorders, arthritic diseases, and postexercise hypotension. Nevertheless, there is still a lack of systematic reviews on the clinical efficacy of combination therapy, greatly limiting our understanding of its clinical application. Here, we present a comprehensive overview of the current knowledge and perspectives regarding the combination of H1 and H2 histamine receptor antagonists in various histamine-mediated disorders. Furthermore, we critically analyze the adverse effects and limitations associated with combination therapy while suggesting potential solutions. Our review can offer a systematic summary and promising insights into the in-depth and effective application of the combination of H1 and H2 receptor antagonists.

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.

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.

Hidden and Rare Food Allergens in Pediatric Age

In food allergy management, the avoidance of the allergen that caused the reaction plays a fundamental role. Nevertheless, that can be thwarted in case of accidental exposure to a rare or hidden allergen, causing the adoption of a monotonous diet and a consequent reduction in the quality of life of the patient and their family. The identification of a rare and hidden allergen is an important diagnostic challenge, taking into account that a significant proportion of all food reactions is in reality due to them. The aim of the present review is to provide the pediatric allergist an overview of the possible sources of rare and hidden food allergens, taking into consideration the routes of exposure to these potential allergens with the main examples published in the scientific literature and the distinction between types of direct or cross-contamination. The identification of the allergen responsible for the reaction and the provision of a dietary advice customized for the specific individual's dietary habits is essential to improve quality of life of the familiar nucleus and to reduce the risk of further allergic reactions.

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 exon-skipping oligonucleotide, KitStop, depletes tissue-resident mast cells in vivo to ameliorate anaphylaxis

Introduction

Anaphylaxis represents the most extreme and life-threatening form of allergic disease and is considered a medical emergency requiring immediate intervention. Additionally, some people with mastocytosis experience recurrent episodes of anaphylaxis during normal daily activities without exposure to known triggers. While acute therapy consists primarily of epinephrine and supportive care, chronic therapy relies mostly on desensitization and immunotherapy against the offending allergen, which is a time-consuming and sometimes unsuccessful process. These treatments also necessitate identification of the triggering allergen which is not always possible, and thus highlighting a need for alternative treatments for mast cell-mediated diseases.

Methods

The exon-skipping oligonucleotide KitStop was administered to mice intradermally, intraperitoneally, or systemically at a dose of 12.5 mg/kg. Local mast cell numbers were enumerated via peritoneal lavage or skin histology, and passive systemic anaphylaxis was induced to evaluate KitStop's global systemic effect. A complete blood count and biochemistry panel were performed to assess the risk of acute toxicity following KitStop administration.

Results

Here, we report the use of an exon-skipping oligonucleotide, which we have previously termed KitStop, to safely reduce the severity and duration of the anaphylactic response via mast cell depopulation in tissues. KitStop administration results in the integration of a premature stop codon within the mRNA transcript of the KIT receptor-a receptor tyrosine kinase found primarily on mast cells and whose gain-of-function mutation can lead to systemic mastocytosis. Following either local or systemic KitStop treatment, mice had significantly reduced mast cell numbers in the skin and peritoneum. In addition, KitStop-treated mice experienced a significantly diminished anaphylactic response using a model of passive systemic anaphylaxis when compared with control mice.

Discussion

KitStop treatment results in a significant reduction in systemic mast cell responses, thus offering the potential to serve as a powerful additional treatment modality for patients that suffer from anaphylaxis.

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.

Acute abdomen due to anaphylactic intestinal edema associated with systematic mastocytosis: a case report

BACKGROUND

Among various anaphylactic conditions resulting in acute abdomen, mast cell activation disorders, although rare, are included in the differential diagnosis.

CASE PRESENTATION

This report describes a 63-year-old Caucasian man who was brought to the emergency room with sudden onset abdominal pain, vomiting, and diarrhea, with breathing difficulty, and with facial swelling after quarrelling with an acquaintance. Computed tomography showed edematous and swollen intestines, consistent with splenomegaly. Physical findings included maculopapular cutaneous mastocytosis. He also had a long history of repeated episodes of anaphylaxis requiring occasional epinephrine auto-injector administration; however, the precise cause of anaphylaxis was previously undetermined. Blood tests showed high serum concentrations of soluble IL-2R and tryptase, suggesting mast cell-related disease. Subsequent biopsies of his bone marrow and cutaneous rash confirmed the diagnosis of systemic mastocytosis (SM).

CONCLUSION

SM was diagnosed in a patient with acute abdomen who visited the emergency room.

Elevated Histamine Etiology Model for Most Major Vaccine Associated Adverse Events including SARS-CoV-2 Spike Vaccines

Vaccinees experience no adverse events, mild adverse events, multiple adverse events, or serious adverse events post vaccination. Many of these vaccine adverse events occur with different vaccines with different occurrence frequencies. Many of these adverse events are generally considered as associated with immune responses to the active vaccine components (antigens) and/or to possibly one or more of the vaccine excipients. Most of these vaccine adverse events are self-limiting and resolve within days. Many of these adverse events symptoms overlap symptoms associated with elevated histamine levels. Based on these observations, the hypothesis that the majority of vaccine associated reactogenicity adverse events are caused by temporal histamine intolerance in vaccinees is proposed. This hypothesis is based on a model of innate immune responses releasing a surge of inflammatory molecules including histamine; this surge is hypothesized to exceed the normal histamine tolerance level for vaccinees with reactogenicity adverse events. Further, these symptoms resolve as histamine levels fall below the vaccinee's tolerance threshold. This model can be evaluated by the detection of elevated histamine levels in vaccinees corresponding to timing of symptoms onset. If confirmed, a direct consequence of this model predicts that some antihistamine treatments, mast cell stabilizers, and possibly diamine oxidase enzyme may reduce the incidence or severity of adverse events experienced by vaccinees post vaccinations for most or all high reactogenicity vaccines including coronavirus disease 2019 (COVID-19) Spike vaccines.

EAACI guidelines: Anaphylaxis (2021 update)

Anaphylaxis is a clinical emergency which all healthcare professionals need to be able to recognize and manage. The European Academy of Allergy and Clinical Immunology Anaphylaxis multidisciplinary Task Force has updated the 2014 guideline. The guideline was developed using the AGREE II framework and the GRADE approach. The evidence was systematically reviewed and recommendations were created by weighing up benefits and harms. The guideline was peer-reviewed by external experts and reviewed in a public consultation. The use of clinical criteria to identify anaphylaxis is suggested with blood sampling for the later measurement of tryptase. The prompt use of intramuscular adrenaline as first-line management is recommended with the availability of adrenaline autoinjectors to patients in the community. Pharmacokinetic data should be provided for adrenaline autoinjector devices. Structured, comprehensive training for people at risk of anaphylaxis is recommended. Simulation training and visual prompts for healthcare professionals are suggested to improve the management of anaphylaxis. It is suggested that school policies reflect anaphylaxis guidelines. The evidence for the management of anaphylaxis remains mostly at a very low level. There is an urgent need to prioritize clinical trials with the potential to improve the management of patients at risk of anaphylaxis.

Pharmacokinetics of adrenaline autoinjectors

Anaphylaxis is a medical emergency with adrenaline acknowledged as the first-line therapy. It is therefore important that patients have access to self-injectable adrenaline in the community. Manufacturers have been requested by European Medicine Regulators to generate pharmacokinetic data for these autoinjector devices. For the first time, these data provide an insight into how individual devices work in different populations, and how they compare. We undertook a thorough literature search and also accessed grey literature, using searches of medicine regulators' websites and freedom of information requests. The data demonstrate that it takes at least 5-10 min to achieve early peak plasma concentration for most devices. The specific autoinjector device seems to be the most important determinant of pharmacokinetics, with different devices giving rise to different plasma adrenaline profiles. Needle length does not seem to be the most important factor; rather, the force and speed of injection (which varies from one device to another) is likely to be of greater importance. In general, peak plasma adrenaline concentration is lower and time-to-peak concentration longer with increased skin-to-muscle depth. However, it is difficult to draw conclusions with the current available data, due to a lack of head-to-head comparisons, small numbers of study participants and the failure to acknowledge the biphasic nature of intramuscular adrenaline absorption for analysis purposes.

Update on idiopathic anaphylaxis

Idiopathic anaphylaxis (AI) refers to anaphylaxis without a recognizable cause after a comprehensive allergic workup. The diagnostic approach usually includes an accurate clinical history aimed at excluding both the most and the less frequent causes of anaphylaxis and all pathologies that may resemble anaphylaxis. AI is more common in adults than in children. The epidemiology of AI has been reduced in recent years, probably to increase knowledge and discover new clinical entities, such as the α-gal anaphylaxis. Anaphylaxis results from the massive activation of the mast cells (MCs). Thus, it is also necessary to exclude MC disorders, such as mastocytosis and mast cell activation syndrome, and α-tryptasemia, which may manifest with IA symptoms.

Idiopathic anaphylaxis: Diagnosis and management

Introduction: Idiopathic anaphylaxis (IA) is a diagnosis of exclusion and is based on the inability to identify a causal relationship between a trigger and an anaphylactic event, despite a detailed patient history and careful diagnostic assessment. The prevalence of IA among the subset of people who experienced anaphylaxis is challenging to estimate and varies widely, from 10 to 60%; most commonly noted is ∼20% in the adult anaphylactic population. Comorbid atopic conditions, such as food allergy, allergic rhinitis, and asthma, are present in up to 48% of patients with IA. Improved diagnostic technologies and an increased understanding of conditions that manifest with symptoms associated with anaphylaxis have improved the ability to determine a more accurate diagnosis for patients who may have been initially diagnosed with IA. Methods: Literature search was conducted on PubMed, Google Scholar and Embase. Results: Galactose-α-1,3-galactose (α-gal) allergy, mast cell disorders, and hereditary a-tryptasemia are a few differential diagnoses that should be considered in patients with IA. Unlike food allergy, when anaphylaxis occurs within minutes to 2 hours after allergen consumption, α-gal allergy is a 3-6-hour delayed immunoglobulin E-mediated anaphylactic reaction to a carbohydrate epitope found in red meat (e.g., beef, lamb, pork). The more recently described hereditary α-tryptasemia is an inherited autosomal dominant genetic trait caused by increased germline copies of tryptase human gene alpha-beta 1 (TPSAB1), which encodes α tryptase and is associated with elevated baseline serum tryptase. Acute management of IA consists of carrying an epinephrine autoinjector to be administered immediately at the first signs of anaphylaxis. Long-term management for IA with antihistamines and other agents aims to potentially reduce the frequency and severity of the anaphylactic reactions, although the evidence is limited. Biologics are potentially steroid-sparing for patients with IA; however, more research on IA therapies is needed. Conclusion: The lack of diagnostic criteria, finite treatment options, and intricacies of making a differential diagnosis make IA challenging for patients and clinicians to manage.

Omalizumab for prevention of anaphylactic episodes in a patient with severe mosquito allergy

Anaphylaxis after mosquito bite is rare, but life threatening. No approved preventive therapy is available to date, but omalizumab could be a promising therapeutic option for reducing risk and improving quality of life in these patients.

Developments allergy in 2019 through the eyes of Clinical and Experimental Allergy, Part II clinical allergy

In the second of two linked articles, we describe the development in clinical as described by Clinical & Experimental Allergy and other journals in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered. In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered.

Fatal anaphylaxis in Italy: Analysis of cause-of-death national data, 2004-2016

BACKGROUND

Epidemiological data on fatal anaphylaxis are underestimated worldwide. Few Italian data do exist. The aims of the study are to determine the anaphylaxis mortality rate in Italy and its associations with demographic characteristics (gender, age, and geographical distribution), and to investigate which are the most common triggers of fatal anaphylaxis.

MATERIAL AND METHODS

This is a descriptive study analyzing data reported to the National Register of Causes of Death database and managed by the Italian National Institute of Statistics for the years 2004-2016. An analytical method was developed to identify all the ICD-10 codes related to anaphylaxis deaths, which were divided into two classes: "Definite anaphylaxis deaths" and "Possible anaphylaxis deaths."

RESULTS

From 2004 through 2016, 392 definite anaphylaxis deaths and 220 possible anaphylaxis deaths were recorded. The average mortality rate for definite anaphylaxis, from 2004 to 2016, was 0.51 per million population per year. Definite fatal anaphylaxis was mostly due to the use of medications (73.7%), followed by unspecified causes (20.7%) and hymenoptera stings (5.6%). Concerning possible anaphylaxis deaths, the most common cause was venom-stinging insect (51.4%). We did not find any data on food fatal anaphylaxis. Unspecified anaphylaxis accounted for 21%-28% of all cases, underlining the difficulty in accurately ascertaining the causes of fatal anaphylaxis and therefore in assigning the proper ICD-10 code.

CONCLUSION

This is the first study of anaphylaxis-related mortality coming from an official database of the whole Italian population. However, the actual number of deaths by anaphylaxis, and their related triggers, is probably underreported, mostly due to limitations of the current recording system, and to a poor allergy education. Corrective actions should be undertaken for the benefit of the Health System.

World allergy organization anaphylaxis guidance 2020

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

Near-fatal anaphylaxis with Kounis syndrome caused by Argas reflexus bite: a case report

Background

The pigeon tick Argas reflexus is a temporary parasite of pigeons. It bites during night hours and lies briefly on its prey, as long as it takes the blood meal. When pigeons are not accessible, ticks look for other hosts, invading nearby flats and biting humans.

Case presentation

We present the case of a woman aged 46 years who experienced severe anaphylaxis during the night which required emergency medical treatment, tracheal intubation and hospitalization in intensive care unit. Kounis syndrome was documented by transient ST depression and elevation of troponin. The allergological work up ruled out hypersensitivity to drugs, latex and foods containing alpha-gal, which is a cause of anaphylaxis. Basal serum tryptase was in normal range (8.63 ng/ml). When questioned about the presence of ticks, the patient brought into view various specimens of ticks that were recognized by an entomologist as Argas reflexus.

Conclusions

An in vitro diagnosis of allergy to Argas reflexus is currently not feasible because, though the major allergen Arg r 1 has been isolated, allergen extracts are not commercially available. Therefore, the diagnosis of anaphylaxis from Argas reflexus, when other causes of anaphylaxis are excluded, must rely only on history and clinical findings, as well as on the presence of pigeons and/or pigeon ticks in the immediate domestic environment.