Evaluation of the passive mast cell activation test for identifying allergens in perioperative anaphylaxis: a study protocol for a prospective diagnostic accuracy study.

INTRODUCTION: Perioperative anaphylaxis (POA) can lead to significant complications. Therefore, accurate identification of allergens for POA patients is critical to ensure the safety of future surgical and anaesthetic procedures. Existing perioperative allergen detection methods face challenges in sensitivity and specificity. The passive mast cell activation test (pMAT) has recently emerged as a potential diagnostic tool. Our study aims to evaluate the diagnostic efficacy of pMAT for identifying perioperative allergens, with a focus on non-depolarising neuromuscular blocking agents, the most common culprits of POA. METHODS AND ANALYSIS: This prospective diagnostic accuracy study will measure the diagnostic accuracy of pMAT in POA patients. Participants will undergo skin testing (ST), basophil activation testing (BAT) and pMAT. The diagnostic validity of pMAT will be assessed based on the results of ST and BAT. The assessment of diagnostic accuracy will include sensitivity, specificity, likelihood ratios, and false-positive and false-negative rates while measurement of the consistency rate will assess reliability. ETHICS AND DISSEMINATION: This study has been approved by the Institutional Review Board of China-Japan Friendship Hospital (2023-KY-247). Results will be disseminated through academic presentations and peer-reviewed journal publications and will provide valuable scientific data and some new insights into the diagnostic accuracy of pMAT.

[A fish-intoxication as a rare cause of chest pain]. / Eine Fischintoxikation als seltene Ätiologie des Thoraxschmerzes.

INTRODUCTION: We describe the case of a 58-year-old patient who developed chest pain and an anaphylaktoide reaction after ingestion of contamined fish containing histamin. Histamin intoxication from food poisoning (also known as scombroid intoxication) can be mistaken for an anaphylactic reaction and occasionaly lead to cardiac symptoms, even in patients without atherosclerotic changes. This condition is called Kounis syndrom and has to be recognized as a separate syndrom with specific clinical features.

Venom Hypersensitivity.

Stinging insects are a frequent cause of local and systemic hypersensitivity reactions, including anaphylaxis. For those with a history of life-threatening anaphylaxis, venom immunotherapy is effective, safe, and can be life-saving. Arachnids are a much less common source of envenomation through bites or stings and are less likely to cause a hypersensitivity reaction. However, recognizing the clinical manifestations when they do present is important for accurate diagnosis and treatment, and, when indicated, consideration of other diagnoses.

Evaluation of treatment and long-term management of anaphylaxis in pediatric departments of Greece: a 2-year nationwide survey.

BACKGROUND: Anaphylaxis proportions of incidence are increasing globally. However, limited data are available regarding anaphylaxis in the pediatric population of Greece. PURPOSE: The aim of the study was to evaluate management of anaphylaxis in Greek pediatric departments. METHODS: We performed a questionnaire-based study of children aged less than 16 years presenting with anaphylaxis in 10 national pediatric hospitals over a period of 2 years. Management of anaphylaxis was assessed prior to and after an informative intervention. RESULTS: In all, 127 cases of anaphylaxis were identified. Epinephrine was administered in almost half of all cases (51.2%), predominantly through intramuscular route (88.5%), while the majority of anaphylaxis patients were treated with antihistamines (92.9%) and corticosteroids (70.1%). Epinephrine was more likely administered by physicians if the elicitor was a drug (P < 0.003). Regarding long-term management, an epinephrine auto-injector was prescribed in 66.9% of patients. Follow-up information was available for most of the patients (92.9%), the majority of whom (76.3%) were referred to an allergist. More than half of these patients (63.6%) had a documented allergy follow-up, which identified a causative allergen in 53.3% of cases. No statistically significant differences were recorded prior to and after the intervention regarding management of anaphylaxis. CONCLUSIONS: This nationwide study highlighted the necessity of further improvement in terms of anaphylaxis treatment and secondary prevention measures. This presupposes appropriate education and training of healthcare professionals, thus contributing to proper and comprehensive care of the pediatric population.

Alpha-gal syndrome: when treatment of hypovolemic shock can lead to anaphylaxis.

Delayed anaphylaxis after ingestion of red meat because of galactose-alpha-1,3-galactose (alpha-gal) syndrome has increased in recent years. The mechanism involves an immunoglobulin E reaction to alpha-gal, a molecule found in mammalian meat, dairy products, medications and excipients containing mammalian-derived components, and tick salivary glycans. Sensitization occurs due to the bite of a lone star tick and the transmission of alpha-gal molecules into person's bloodstream. We describe a case of alpha-gal syndrome with severe food, drug, and perioperative allergy in which anaphylaxis with hypovolemic shock occurred immediately after an emergency surgical procedure, when a gelatin-containing drug was injected. This case study confirms that the clinical manifestations of alpha-gal syndrome could be different depending on the route of administration, with immediate reactions if an alpha-gal-containing drug is injected and delayed type allergic manifestations occurring several hours after oral intake. The purpose of this report is to highlight the importance of risk communication in case of exposure to medical products and surgical procedures of patients with alpha-gal syndrome and to encourage drug manufacturers to indicate clearly the origin of excipients in product literature.

Perioperative anaphylactic shock caused by propofol.

Perioperative anaphylaxis is rare and the diagnosis is difficult to distinguish from normal side effects from anaesthesia. Anaesthetists should be able to diagnose anaphylaxis and treat promptly with adrenaline and fluids. Allergy investigation should be performed subsequently. This is a case report of perioperative anaphylaxis to propofol. Propofol contains refined soya oil and egg lecithin, but no connection between allergy to soy, egg or peanut and allergy to propofol has been proven, and international guidelines recommend that propofol can be used in patients with these food allergies.

A US-Based Multicenter Retrospective Report of Perioperative Anaphylaxis, 2010-2021.

BACKGROUND: US-based perioperative anaphylaxis (POA) studies are limited to single-center experiences. A recent report found that a serum acute tryptase (sAT) >9.8 ng/mL or mast cell activation (MCA) can predict POA causal agent identification. Urinary mast cell mediator metabolites (uMC) have not been studied in POA. OBJECTIVE: To analyze the epidemiologic data of POA, to determine if sAT or MCA can predict suspected causal agent identification, and to evaluate uMC utility in POA. METHODS: This study is a retrospective multicenter review of POA cases that were subcategorized by suspected causal agent identification status. sAT, MCA (defined as sAT >2 + 1.2 × serum baseline tryptase), and uMC (N-methylhistamine [N-MH], 11ß-prostaglandin-F2α [11ß-PGF2α], leukotriene E4 [LTE4]) were recorded. RESULTS: Of 100 patients (mean age 52 [standard deviation 17] years, 94% adult, 50% female, 90% White, and 2% Hispanic) with POA, 73% had an sAT available, 41% had MCA, 16% had uMC available, and 50% had an identifiable suspected cause. POA cases with an identifiable suspected cause had a positive MCA status (100% vs 78%; P = .01) compared with POA with an unidentifiable cause. An elevated median sAT did not predict causal agent identification. Positive uMC were not associated with suspected causal agent identification during POA. Patients with positive uMC had a higher median sAT (30 vs 6.45 ng/mL; P = .001) and MCA status (96% vs 12%; P = .001) compared with negative uMC patients. Patients with POA had an elevated acute/baseline uMC ratios: 11ß-PGF2α ratio > 1.6, N-MH ratio >1.7, and LTE4 ratio >1.8. CONCLUSIONS: The presence of MCA in POA is associated with suspected causal agent identification. Positive uMC possibly correlate with a higher sAT level and MCA status but require further study. The authors suggest applying an acute/baseline uMC ratio (11ß-PGF2α ratio >1.6, N-MH ratio >1.7, and LTE4 ratio >1.87) in patients with POA for MCA when a tryptase level is inconclusive during POA evaluations.

El pediatra de Atención Primaria y la anafilaxia / The primary care pediatrician and anaphylaxis

La anafilaxia es una reacción alérgica grave de instauración rápida y potencialmente mortal. El diagnóstico de anafilaxia es clínico y debe realizarse de manera precoz. Aparece en las 2 primeras horas tras exposición al alérgeno, en los primeros 30 minutos en alergia alimentaria y más precozmente con medicamentos intravenosos o picaduras de himenópteros. Los síntomas cutáneos suelen ser los primeros en manifestarse y están presentes en la mayoría de los casos, más de un 80%. Pueden ser leves o transitorios e incluso no estar presentes en un 18% de los casos. Si se afecta el sistema cardiocirculatorio estaríamos ante un shock anafiláctico. La causa más frecuente en Pediatría son los alimentos. Existen cofactores cuya presencia aumenta la probabilidad de anafilaxia; los más importantes son: el ejercicio, los fármacos, la fiebre y el estrés. El tratamiento de elección es la adrenalina intramuscular. Tanto los padres como los niños deben saber identificar los signos y/o síntomas del inicio de la anafilaxia para instaurar el tratamiento pautado en el plan de acción escrito.

Anaphylaxis is a severe, rapid and potentially fatal allergic reaction. The diagnosis of anaphylaxis is clinical and must be early. It appears in the first 2 hours after exposure to the allergen, in the first 30 minutes in food allergy and earlier with intravenous drugs or hymenoptera stings. Cutaneous symptoms are generally the first to appear and are present in most cases, more than 80%. They may be mild or transitory, or absent in 18% of cases. If the cardio-circulatory system is affected, an anaphylactic shock occurs. The most frequent cause in pediatrics is nutrition. There are several cofactors whose presence increases the likelihood of anaphylaxis; the most important are: exercise, medication, fever and stress. The treatment of choice is intramuscular adrenaline. Parents and children should be able to identify the signs and/or symptoms of anaphylaxis in order to implement the treatment prescribed in the written action plan. (AU)

Management of food allergy based on oral food challenge.

PURPOSE OF REVIEW: Food allergy is a growing health problem that affects both patients and society in multiple ways. Despite the emergence of novel diagnostic tools, such as component-resolved diagnostics (CRD) and basophil activation tests (BAT), oral food challenge (OFC) still plays an indispensable role in the management of food allergies. This review aimed to highlight the indications and safety concerns of conducting an OFC and to provide insights into post-OFC management based on recent findings. RECENT FINDINGS: Standardized OFC protocols have regional diversification, especially in Japan and Western countries. Recent studies suggested that the interval between doses should be at least more than an hour. Furthermore, applying a stepwise method tailored to the patient's specific immunoglobulin E level and history of anaphylaxis seems to mitigate these risks. Recent surveys have shown that, following a positive OFC, options other than strict avoidance are also selected. SUMMARY: OFC serves diverse purposes, yet the risks it carries warrant caution. The stepwise protocol appears promising for its safety. Subthreshold consumption following OFC shows potential; however, further research on its efficacy and safety is required. Management following OFC should be tailored and well discussed between clinicians and patients.

Alpha-Tryptase as a Risk-Modifying Factor for Mast Cell-Mediated Reactions.

PURPOSE OF REVIEW: To provide an overview on the current understanding of genetic variability in human tryptases and summarize the literature demonstrating the differential impact of mature tryptases on mast cell-mediated reactions and associated clinical phenotypes. RECENT FINDINGS: It is becoming increasingly recognized that tryptase gene composition, and in particular the common genetic trait hereditary alpha-tryptasemia (HαT), impacts clinical allergy. HαT has consistently been associated with clonal mast cell disorders (MCD) and has also been associated with more frequent anaphylaxis among these patients, and patients in whom no allergic trigger can be found, specifically idiopathic anaphylaxis. Additionally, more severe anaphylaxis among Hymenoptera venom allergy patients has been linked to HαT in both retrospective and prospective studies. An increased relative number of α-tryptase-encoding gene copies, even in the absence of HαT, has also been associated with systemic mastocytosis and has been shown to positively correlate with the severity of mast cell-mediated reactions to vibration and food. These findings may be due to increased generation of α/ß-tryptase heterotetramers and differences in their enzymatic activity relative to ß-tryptase homotetramers. HαT is a naturally occurring overexpression model of α-tryptase in humans. Increased relative α-tryptase expression modifies immediate hypersensitivity symptoms and is associated with more frequent and severe mast cell-mediated reactions, ostensibly due to increased α/ß-tryptase heterotetramer production.

Fatal food anaphylaxis in adults and children.

Anaphylaxis is a life-threatening reaction characterized by the acute onset of symptoms involving different organ systems and requiring immediate medical intervention. The incidence of fatal food anaphylaxis is 0.03 to 0.3 million/people/year. Most fatal food-induced anaphylaxis occurs in the second and third decades of life. The identified risk factors include the delayed use of epinephrine, the presence of asthma, the use of recreational drugs (alcohol, nicotine, cannabis, etc.), and an upright position. In the United Kingdom (UK) and Canada, the reported leading causal foods are peanuts and tree nuts. In Italy, milk seems to be the most common cause of fatal anaphylaxis in children < 18 years. Fatal food anaphylaxis in Italian children and adolescents almost always occurs outside and is characterized by cardiorespiratory arrest; auto-injectable adrenaline intramuscular was available in few cases. Mortality from food anaphylaxis, especially in children, is a very rare event with stable incidence, but its risk deeply impacts the quality of life of patients with food allergy and their families. Prevention of fatal food anaphylaxis must involve patients and their families, as well as the general public, public authorities, and patients' associations.

Level of Awareness of Certified Non-critical Care Physicians in Diagnosing, Managing, and Disposing Anaphylactic Cases.

Background: Anaphylaxis is known as an acute, severe hypersensitivity reaction that rapidly initiates after exposure to a triggering agent. It is a life-threatening condition, and early recognition and swift intervention are crucial to saving patients' lives. Objective: The objective of this study is to assess the ability of certified non-critical care physicians to recognize, manage, and dispose cases of anaphylaxis. Methods: A survey consisting of 19 questions was developed by expert emergency consultants to evaluate physicians' knowledge regarding the recognition, management, and disposition of anaphylactic episodes. Responses were collected through in-person surveys conducted with physicians from various specialties and varying clinical experience levels at a tertiary care center in the Eastern Province of Saudi Arabia. Results: In this cross-sectional study, a total of 173 physicians completed the survey, with 81.5% being consultants and 18.5% specialists. Only 5.2% correctly identified all three proposed anaphylaxis clinical scenarios, 16.8% identified two scenarios correctly, and 51.4% identified only one scenario. While 42.8% recognized the first-line management of anaphylaxis, only 24.3% and 24.9% knew the correct epinephrine dose and route, respectively. Regarding the disposition of patients experiencing an anaphylactic episode, 61.9% of responders opted to dispose the case to the emergency department. Conclusion: Our study reveals a knowledge gap among non-critical care physicians practicing in a tertiary care center concerning the identification and management of anaphylaxis. Raising awareness of this life-threatening condition is imperative to address this serious issue.

Cold-induced anaphylaxis triggered by drinking cold water.

Cold urticaria is an inducible urticaria in which hives and angioedema appear after exposure to cold. The symptoms of cold urticaria often are limited to hives/angioedema. However, in up to 20% of cases, cold exposure may trigger anaphylaxis. We report the case of an 11-year-old boy previously diagnosed with chronic spontaneous urticaria who developed facial swelling, itchy hives, difficulty in breathing, vomiting and abdominal pain within 5 minutes of drinking cold water. He received a standard dose of non-sedating second-generation antihistamines at home. He was observed in the emergency room for 2 hours and discharged with an epinephrin autoinjector. During the subsequent outpatient clinic visit, an ice cube test was performed which confirmed the new diagnosis of comorbid cold-induced chronic urticaria. On further questioning, the parents reported occurrence of hives following swimming in the swimming pool. Cold-induced urticaria should be suspected in cases of anaphylaxis associated with cold exposure. Patients with chronic forms of urticaria who present with new anaphylaxis should be assessed for a potential concomitant cold-induced form.

Allergy to Gibberellin-regulated proteins in an adolescent: A case of orange-induced anaphylaxis mediated by cofactors.

This report is a case of anaphylaxis in an adolescent due to allergy to gibberellin-regulated proteins mediated by cofactors, in probable relation to a pollen/food allergy syndrome. It should also emphasizes the importance of obtaining a faithful clinical history, especially when it comes to adolescent patients as they tend to initiate toxic habits.

A rare case of lysozyme-induced anaphylaxis in a child with egg allergy.

We report an unusual case of anaphylaxis induced by the lysozyme-containing over-the-counter-drug Lysopaine®, which contains 20 mg lysozyme hydrochloride and 1.5 mg cetylpyridinium chloride, in a 9-year-old child with allergy to hen's egg as well as multiple IgE-mediated food allergies. The involvement of lysozyme was confirmed by positive skin prick tests for Lysopaine® and the presence of specific IgE against lysozyme. Our case highlights the importance of properly educating allergic patients to recognize allergens, even minor ones. Despite the presence of lysozyme in various food and drug products, it is not necessarily perceived as an allergenic protein by patients with egg allergy, and the labeling may be misleading, thereby exposing patients to potentially severe reactions.

Novel use of dynamic MR hydrography to rule out esophageal perforation post atrial fibrillation ablation in a patient with anaphylaxis to gadolinium.

Esophageal thermal injury is one of the most devastating complications of atrial radiofrequency ablation, and its diagnosis can be challenging. In this report, we highlight the novel use of free water as a contrast material to better visualize the esophageal lumen in a patient with anaphylaxis to Iodinated contrast media and Gadolinium who recently underwent atrial fibrillation ablation. This becomes particularly handy in patients with contrast allergy, and further emphasizes the role of multimodality imaging.

Reversible Elevation of Tryptase Over the Individual's Baseline: Why is It the Best Biomarker for Severe Systemic Mast Cell Activation and MCAS?

PURPOSE OF REVIEW: Mast cell (MC) activation syndromes (MCAS) are conditions defined by recurrent episodes of severe systemic anaphylaxis or similar systemic events triggered by MC-derived mediators that can be measured in biological fluids. Since some symptoms of MC activation may occur due to other, non-MC etiologies and lead to confusion over diagnosis, it is of crucial importance to document the involvement of MC and their products in the patients´ symptomatology. RECENT FINDINGS: The most specific and generally accepted marker of severe systemic MC activation is an event-related, transient increase in the serum tryptase level over the individual baseline of the affected individual. However, baseline concentrations of serum tryptase vary among donors, depending on the genetic background, age, kidney function, and underlying disease. As a result, it is of critical importance to provide a flexible equation that defines the diagnostic increase in tryptase qualifying as MCAS criterion in all patients, all situations, and all ranges of baseline serum tryptase. In 2012, the consensus group proposed the 120% + 2 ng/ml formula, which covers the great majority of groups, including cases with low, normal, or elevated basal serum tryptase level. This formula has been validated in subsequent studies and has proven to be a robust and consistent diagnostic criterion of MCAS. The present article is discussing the impact of this formula and possible limitations as well as alternative markers and mediators that may be indicative of MCAS.