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.

Peri-operative cardiac arrest due to suspected anaphylaxis as reported to the 7th National Audit Project of the Royal College of Anaesthetists

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied peri-operative cardiac arrest. Among 59 cases reported as possible anaphylaxis, 33 (56%) were judged to be so by the review panel with high or moderate confidence. Causes in excluded cases included: isolated severe hypotension; bronchospasm; and oesophageal intubation. Severe bronchospasm leading to cardiac arrest was uncommon, but notably in one case led to a reported flat capnograph. In the baseline survey, anaesthetists estimated anaphylaxis as the cause of 10% of cases of peri-operative cardiac arrests and to be among the four most common causes. In a year-long registry of peri-operative cardiac arrest, suspected anaphylaxis was the seventh most common cause accounting for 4% of reports. Initial management was most often with low-dose intravenous adrenaline, and this was without complications. Both the NAP7 baseline survey and case registry provided evidence of reluctance to starting chest compressions when systolic blood pressure had fallen to below 50 mmHg and occasionally even when it was unrecordable. All 33 patients were resuscitated successfully but one patient later died. The one death occurred in a relatively young patient in whom chest compressions were delayed. Overall, peri-operative anaphylaxis leading to cardiac arrest occurred with a similar frequency and patterns of presentation, location, initial rhythm and suspected triggers in NAP7 as in the 6th National Audit Project (NAP6). Outcomes in NAP7 were generally better than for equivalent cases in NAP6.

Emergency treatment of peri-operative anaphylaxis: Resuscitation Council UK algorithm for anaesthetists

Peri-operative anaphylaxis is a rare but potentially catastrophic event which must be considered whenever unexpected and significant cardiovascular or respiratory compromise occurs during anaesthesia. The Resuscitation Council UK algorithm for peri-operative anaphylaxis highlights the importance of early intravenous adrenaline and fluid resuscitation and provides guidance on the treatment of refractory anaphylaxis and immediate follow-up. This algorithm is endorsed by the Royal College of Anaesthetists, Association of Anaesthetists, British Society of Allergy and Clinical Immunology and Clinical Immunology Professional Network of the British Society for Immunology. This document was produced by the Perioperative Allergy Network steering committee in collaboration with the Resuscitation Council UK.

Current update on anaphylaxis: anaphylaxis management in recent guidelines

Summary

Anaphylaxis is a potentially fatal hypersensitivity reaction but frequently underrecognized. Although its incidence rates vary according to geographical location, it seems clear that there has been a general increase in recent years, either because of greater recognition of this entity or because it is progressing proportionally to the presence of allergic diseases in the world. The development of anaphylaxis management guidelines adapted to local or regional needs seems of utmost importance. Furthermore, it is necessary to assess their implementation and their positive effect regarding diagnosing and treating anaphylaxis. In this review we explore the currently existing definitions of anaphylaxis and its epidemiology, the potential triggers of anaphylaxis and guideline recommendations in terms of diagnosis and management, proposing a novel anaphylaxis calculator and reviewing the current scoring methods for anaphylactic episodes.

Management of Food Allergies and Food-Related Anaphylaxis

Importance

An estimated 7.6% of children and 10.8% of adults have IgE-mediated food-protein allergies in the US. IgE-mediated food allergies may cause anaphylaxis and death. A delayed, IgE-mediated allergic response to the food-carbohydrate galactose-α-1,3-galactose (alpha-gal) in mammalian meat affects an estimated 96 000 to 450 000 individuals in the US and is currently a leading cause of food-related anaphylaxis in adults.

Observations

In the US, 9 foods account for more than 90% of IgE-mediated food allergies-crustacean shellfish, dairy, peanut, tree nuts, fin fish, egg, wheat, soy, and sesame. Peanut is the leading food-related cause of fatal and near-fatal anaphylaxis in the US, followed by tree nuts and shellfish. The fatality rate from anaphylaxis due to food in the US is estimated to be 0.04 per million per year. Alpha-gal syndrome, which is associated with tick bites, is a rising cause of IgE-mediated food anaphylaxis. The seroprevalence of sensitization to alpha-gal ranges from 20% to 31% in the southeastern US. Self-injectable epinephrine is the first-line treatment for food-related anaphylaxis. The cornerstone of IgE-food allergy management is avoidance of the culprit food allergen. There are emerging immunotherapies to desensitize to one or more foods, with one current US Food and Drug Administration-approved oral immunotherapy product for treatment of peanut allergy.

Conclusions and Relevance

IgE-mediated food allergies, including delayed IgE-mediated allergic responses to red meat in alpha-gal syndrome, are common in the US, and may cause anaphylaxis and rarely, death. IgE-mediated anaphylaxis to food requires prompt treatment with epinephrine injection. Both food-protein allergy and alpha-gal syndrome management require avoiding allergenic foods, whereas alpha-gal syndrome also requires avoiding tick bites.

Predictors of severe and recurrent adult anaphylaxis, and gaps in the cascade of care: a retrospective, single-centre study 2009-2018

BACKGROUND

Anaphylaxis is a severe, potentially fatal, systemic allergic reaction. Understanding predictors of recurrent and severe anaphylaxis in adults, and identifying gaps in ongoing anaphylaxis care, is needed to minimise its impact.

AIMS

To evaluate the risk factors in adults with severe and recurrent anaphylaxis presentations and to evaluate the management of patients in regard to the recommended cascade of care.

METHODS

We completed a retrospective audit of adults with confirmed anaphylaxis who presented to an inner-city emergency department from 1 January 2009 through 31 December 2018. Data recorded included demographics, background history, medication use, severity, co-factors, triggers, management, discharge disposition and referral for follow-up. Data were managed in REDCap and analysed using Stata. Associations were assessed through odds ratios (ORs) and t tests.

RESULTS

Six hundred sixteen individuals had 689 episodes of anaphylaxis over the audit period. Age over 65 (OR: 5.4 (95% confidence interval, CI: 2.3-13.2), P < 0.0001) and history of asthma (OR: 1.6 (95% CI: 1.03-2.5), P = 0.03) were independent risk factors for severe anaphylaxis. History of food allergy (P < 0.001) and food as the trigger were associated with recurrent presentations (OR: 2.1, 95% CI: 1.1-3.9, P = 0.01). Only 19% of patients met the recommended cascade of care, with post-adrenaline monitoring and recommending follow-up with an allergy specialist demonstrating the largest gaps. There were increased presentations with time but no difference in triggers or severity.

CONCLUSIONS

Increased age and asthma were identified as risk factors for severe presentations. History of food allergy was a risk factor for recurrent presentations. Further research is needed on the gaps in care for adults with anaphylaxis to identify the reasons why, so we can better care for these patients.

Bee venom: apitherapy and more

Honeybees are becoming increasingly familiar to the general population due to the growing popularity of backyard and amateur beekeeping. Although bee venom produces reactions ranging from mild local irritation to life-threatening anaphylaxis, it is also used for life-saving desensitization immunotherapy in those with severe reactions to bee stings. The use of honeybee venom for immunotherapy has increased due to an enhanced interest in natural therapeutics. Recently, honeybee venom has been administered as a successful, safe, and cost-effective treatment for rheumatoid arthritis, back pain, and skin diseases. During the past two decades, studies have tested honeybee venom's efficacy for treating various skin disorders, including atopic dermatitis, wound healing, and psoriasis. We will review bee venom from multiple perspectives, including its medical applications and mechanisms for dermatological pathologies.

[TWO CASES OF LARYNGEAL EDEMA CAUSED BY SUBLINGUAL ALLERGEN IMMUNOTHERAPY]

Sublingual immunotherapy is a widely used treatment, and serious adverse reactions such as anaphylaxis are rare. We report two cases of laryngeal edema as adverse reactions to sublingual immunotherapy, which could be continued due to a change in the administration method. Case 1 presents a 15-year-old male suspected to have had anaphylaxis due to the dust at the age of 6 years. He started treatment with Miticure® and developed laryngeal edema 30 minutes after taking the 10000JAU dose on the 10th day. laryngeal edema was treated with intravenous infusion. Case 2 presents a 48-year-old woman. She started treatment with Cidacure® and developed respiratory distress and laryngeal edema 1 hour after taking the 5000JAU dose on the 5th day. she had resolved mildly without therapeutic intervention. In both cases, the patients were switched to sublingual spitting, resumed with the initial dose cautiously, and were able to continue. Sublingual immunotherapy is a safe treatment, but sudden adverse reactions may occur. Laryngeal symptoms may be treated by changing to the sublingual spitting method, but laryngeal findings should be examined, and the dosage should be carefully increased.

Fish Allergy and Related Conditions in Children: A Review

Fish allergy is the important food allergies in childhood, often persisting into adulthood. It can cause severe hypersensitivity reactions, including fatal anaphylaxis; furthermore, avoiding-fish diet has negative nutritional and psychological effects. Recent research studies focus on epitope structures and aim to develop sensitive and specific diagnostic tools, which have a better correlation with clinical reactions. Protocols with hypoallergenic parvalbumin or other recombinant antigens are also under study and will likely lead to new immunotherapy protocols. IgE-mediated fish allergy differs substantially from other forms of immunological adverse reactions to fish, such as Food Protein-Induced Enterocolitis Syndrome and eosinophilic esophagitis. In addition, fish ingestion can cause non-immunological adverse reactions, such as in the case of scombroid poisoning, anisakiasis and toxic poisoning. This review aims to summarize the characteristics of the main immunological and non-immunological fish reactions, analyzing the epidemiology, clinical manifestations, diagnosis and therapy, with a particular focus on clinical management.

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.

Perioperative anaphylaxis management and testing: a quaternary centre audit

BACKGROUND

Anaphylaxis is a severe, potentially life-threatening generalized or systemic hypersensitivity reaction. Sequential reports have cited anaphylaxis as the most common cause of anaesthesia-related deaths. We undertook an audit at a quaternary centre, examining the management of perioperative anaphylaxis and quality of referrals made to our anaesthesia allergy testing service.

METHODS

The data of 41 patients consulted at St Vincent's Hospital Melbourne for perioperative anaphylaxis between 17th of January 2020 and 20th of January 2022 were analysed. Intervention outcomes included total intravenous fluid administered, adrenaline administration, instigation of CPR and the collection and the timing of serum tryptase samples. We also assessed referral quality, provision of institutional allergy alert and time elapsed from the anaphylaxis event to allergy testing. Contemporaneous Australian and New Zealand Anaesthetic Allergy Group (ANZAAG) guidelines were used as the reference standard for most outcomes.

RESULTS

Our data reveals compliance of <80% with respect to intravenous fluid administration, referral quality and tryptase sampling, particularly at the 4-h timepoint.

CONCLUSION

Surgical leadership and patient advocacy in the post-acute phase would likely facilitate requisite testing and improve the quality of counselling. We recommend institutions adopt a case-by-case review of management compliance with recommendations. Additionally, we advocate for the inclusion of a prompt to the ANZAAG referral form, that encourages the operator to update their patient's institutional allergy alert while awaiting allergy testing.

Wheat-dependent exercise-induced anaphylaxis: Subtypen, Diagnostik und Management

Die wheat‐dependent exercise‐induced anaphylaxis (Anstrengungs‐getriggerte Weizenallergie, WDEIA) ist eine IgE‐vermittelte Nahrungsmittelallergie, bei der es nur zu allergischen Symptomen kommt – welche von intermittierender Urtikaria bis hin zu schweren Anaphylaxien reichen können –, wenn Weizen im zeitlichen Zusammenhang mit verstärkenden Kofaktoren wie körperlicher Bewegung, nichtsteroidalen Antirheumatika oder Alkohol verzehrt wird. In den meisten Fällen weisen die Patienten eine Sensibilisierung auf ω5‐Gliadin in der Glutenfraktion des Weizens auf. ω5‐Gliadin‐negative Subtypen der WDEIA sind oft schwierig zu diagnostizieren und können durch Tri a 14 (Weizen‐Lipid‐Transferprotein), durch perkutane Sensibilisierung mit hydrolysierten Weizenproteinen oder, in seltenen Fällen, durch eine Gräserpollenkreuzreaktivität verursacht werden. Die Diagnose wird anhand der Anamnese in Kombination mit dem serologischen IgE‐Profil, Hauttests, Basophilenaktivierungstests und einer Provokationstestung mit Weizengluten und Kofaktoren gestellt. Die individuelle Ernährungsberatung ist nach wie vor die zentrale Säule im Management von Patienten mit WDEIA. Eine komplett weizenfreie Diät stellt eine mögliche Option dar, jedoch scheint diese die Toleranz weniger zu fördern als der weitergeführte regelmäßige Verzehr glutenhaltiger Getreidesorten, dieses allerdings nur bei gleichzeitiger Meidung von Kofaktoren. Alle Patienten sollten ein Notfallset zur Selbstbehandlung inklusive einem Adrenalin‐Autoinjektor erhalten und entsprechend geschult werden. Zur sublingualen Immuntherapie bei WDEIA, einer potenziell vielversprechenden therapeutischen Perspektive, werden weitere Daten benötigt. Dieser Artikel gibt einen Überblick über den aktuellen Wissensstand zur Diagnostik und zum Management bei WDEIA, einschließlich eines optimierten Provokationsprotokolls mit Weizengluten und Kofaktoren.

Wheat-dependent exercise-induced anaphylaxis: subtypes, diagnosis, and management

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is an IgE-mediated food allergy with allergic symptoms ranging from intermittent urticaria to severe anaphylaxis that occurs when wheat ingestion is combined with augmenting cofactors such as exercise, non-steroidal anti-inflammatory drugs, or alcohol. In most cases, patients are identified by sensitization to ω5-gliadins in the gluten fraction of wheat. ω5-gliadin-negative subtypes of WDEIA are often difficult to diagnose and may be caused by Tri a 14 (wheat lipid transfer protein), after percutaneous sensitization with hydrolyzed wheat proteins, or, in rare cases, by cross-reactivity to grass pollen. Diagnosis is established based on the patients' history in combination with serum IgE profile, skin testing, basophil activation tests, and challenge tests with cofactors. Individual dietary counselling remains the central pillar in the management of WDEIA patients. A completely wheat-free diet is a possible option. However, this appears to promote tolerance less than continued regular consumption of gluten-containing cereals in the absence of cofactors. All patients should have an emergency set for self-treatment including an adrenaline autoinjector and receive adequate instruction. More data are needed on sublingual immunotherapy for WDEIA, a potentially promising therapeutic prospect. This article provides an overview of current knowledge on the diagnosis and management of WDEIA including an optimized challenge protocol using wheat gluten and cofactors.

[Precise diagnosis and management of anaphylaxis based on phenotypes and endotypes]

Anaphylaxis is the most severe allergic reaction, demanding immediate management by health care providers, which is currently underdiagnosed and undertreated in China. In addition to the classic IgE-mediated pathway, non-IgE dependent pathway has also been extensively studied in the pathogenesis of anaphylaxis. Recently, the atypical symptoms induced by widespread used monoclonal antibodies and biologics have been reported. The goal of this article is to recognize the phenotypes (triggers and presentation) and understand its characteristics through endotypes (mechanisms) of anaphylaxis. Ultimately, the aim is to help allergists and health care providers guide a precision approach to diagnose and manage of anaphylaxis.

Delayed anaphylaxis due to Alpha-gal allergy: A modified desensitization protocol with red meat in an adult patient

Alpha-gal allergy is the sensitization to Alpha-gal present in saliva when a tick bites and the development of an IgE-mediated reaction to Alpha-gal also present in red meat by cross-reactivity. In contrast to other food allergies, symptoms occur as late as 2-6 hours after a meal. Prick to prick testing with nonmammalian meat in combination with cooked mammalian meat is recommended for diagnosis. However, the main diagnostic test is Alpha-gal sIgE> 0.1 IU/mL. The primary recommendation in patients with Alpha-gal syndrome is to prevent new tick bites and avoid all mammalian meats. Since most of the dishes in our country's food culture contain red meat, elimination diet may adversely affect patients quality of life. In the management of these patients, the option of desensitization with red meat can be considered by evaluating the benefit-risk ratio together with the patient. Our patient with a history of tick bites and a reaction pattern ranging from urticaria to anaphylaxis two hours after meat consumption was evaluated for Alpha gal allergy. The patient was found to be positive by prick-to-prick with cooked red meat. In addition, the high level of Alpha-gal specific IgE (27.3 Ku/L) confirmed the Alpha-gal allergy, and the decision to apply desensitization with red meat was taken. There are only two literatures on this subject, one of which includes two adult cases and the other a single pediatric case. Since a reaction developed in the fifth step of the 27-step desensitization scheme (Ünal et al.), which we took as a reference, which led to a dose increase of more than 100 times, we modified the protocol by using an intermediate steps. We repeated the prick-to-prick test with red meat after desensitization in our case who successfully completed the modified desensitization protocol. Observation of more than half reduction in test edema diameter concretely supports the success of our modified desensitization protocol.

Extracorporeal membrane oxygenation support in refractory anaphylactic shock after bee stings: A case report

An allergy to insect stings is one of the most frequent causes of anaphylactic reactions. Such reactions can be fatal, even on the first reaction, although it very rarely happens. The use of veno-arterial extracorporeal membrane oxygenation (VA ECMO) in refractory anaphylactic shock was previously described. We report a case of a 31-year-old female who presented with refractory anaphylactic shock after bee stings without the presence of cutaneous manifestations other than the rashes in her neck. The toxic component of bee venom and systemic allergic response plays a vital role in pathophysiology. She did not respond to conventional advanced life support, but following urgent VA ECMO, she survived neurologically intact. Despite an uncommon indication for anaphylaxis, ECMO support may be possible and effective in patients with refractory shock.

Drug allergy in primary care: systematic review to support quality improvement initiative of management and optimization of healthcare pathways

PURPOSE OF REVIEW

The aim of this study was to review the practice of general practitioners (GPs) in regard to the diagnosis and management of drug hypersensitivity reactions (DHRs) to identify major challenges and to facilitate the development of decision support tools to GPs confronted with DHRs patients.

RECENT FINDINGS

DHRs are still a challenge in the GPs clinical practice, which implies difficulties in clinical decisions and referral to allergy specialists.

SUMMARY

DHRs can range from mild to severe and even life-threatening. Drugs are the main cause of anaphylaxis deaths in most countries. Most DHRs are firstly seen by GPs, paediatricians or emergency doctors. However, our systematic review demonstrated difficulties in differentiating DHRs from other drug side effects. Most DHRs epidemiological data are from hospital and emergency departments, which may not reflect the real-life experience in primary care. GPs should be aware of the alert signs of DHRs: the involvement of other systems beyond the skin and/or atypical skin/ mucosal involvement, which mandated immediate referral to an emergency department. Data still stress difficulties in the recognition of DHRs clinical manifestations and highlight the need for decision aids to support their management by GPs. Structured clinical history and clinical examination are key diagnostic tools. Reasons for referring to allergy specialists based on the literature are to investigate cause, to undergo specific procedure, such as desensitization and to identify well tolerated, alternative drugs.

Refractory Anaphylaxis: A New Entity for Severe Anaphylaxis

Anaphylaxis reactions lie on a spectrum of severity, ranging from relatively mild lower respiratory involvement (depending on the definition of anaphylaxis used) to more severe reactions that are refractory to initial treatment with epinephrine and may rarely cause death. A variety of grading scales exist to characterize severe reactions, but there is a lack of consensus about the optimal approach to define severity. More recently, a new entity called refractory anaphylaxis (RA) has emerged in the literature, characterized by the persistence of anaphylaxis despite initial epinephrine treatment. However, slightly different definitions have been proposed to date. In this Rostrum, we review these definitions as well as data relating to epidemiology, elicitors, risk factors, and management of RA. We propose a need to align the different definitions for RA, to improve epidemiological surveillance, advance our understanding of the pathophysiology of RA, and optimize management strategies to reduce morbidity and mortality.

Supporting Families Facing Lactation Anaphylaxis: A Case Report

Lactation anaphylaxis is a rare condition that may occur consequent to breastfeeding. Early identification and management of symptoms is paramount to the physical well-being of the birthing person. Supporting newborn feeding goals is also a key component of care. In cases in which the birthing person wants to exclusively feed human milk, planning should include streamlined access to donor milk. Clear communication between health care providers and developing systems to access donor milk for parental indications may help address barriers.

Grading the severity of anaphylaxis

PURPOSE OF REVIEW

Despite no global consensus on a definition of anaphylaxis, there is increasing recognition that just as allergic reactions lie on a spectrum of severity, the same is for anaphylaxis. A variety of severity scores exist in the literature. We review the approaches taken to develop these scores, and their relative advantages and disadvantages.

RECENT FINDINGS

There have been four recent comparisons of published severity scores. All have highlighted the heterogeneity between scoring systems, and the lack of transferability from one approach to another. Notably, only one score has been developed using a data-driven approach, and none has undergone formal and comprehensive validation.

SUMMARY

It is unclear whether a single severity score is achievable, or indeed desirable. If the aim is to guide management of acute reactions, then assignment of severity is not only unnecessary but might delay treatment and cause harm. Severity scores are needed in the research setting, but require an approach which can discriminate between reactions of similar but nonidentical severity (particularly, nonanaphylaxis reactions). Any approach should be fit for purpose, informed by patient and clinician experience, and ideally be data-driven to minimize subjective bias and facilitate objective validation.

Food-Dependent Exercise-Induced Wheals/Angioedema, Anaphylaxis, or Both: A Systematic Review of Phenotypes

BACKGROUND

Food-dependent exercise-induced allergic reactions can manifest with wheals, angioedema, and anaphylaxis, alone or in combination.

OBJECTIVE

To systematically review the clinical manifestation, culprit foods and exercise, augmenting factors, comorbidities, and treatment options of each phenotype.

METHODS

Using predefined search terms, we assessed and analyzed the relevant literature until June 2021. Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations were applied to this systematic review.

RESULTS

A total of 231 studies with 722 patients were included. The most common phenotype was anaphylaxis with wheals, angioedema, or both, reported in 80% of patients. This was associated with a higher number of anaphylactic episodes, augmenting factors, and use of on-demand antihistamine compared with the least common phenotype, anaphylaxis without wheals or angioedema, reported in 4% of patients. Anaphylaxis with wheals/angioedema was also associated with distinct characteristics compared with stand-alone wheals, angioedema, or both, in 17% of patients. Patients with anaphylaxis were older at the time of disease onset, less often had a history of atopy, showed more positive results in response to food and exercise provocation tests, had a more restricted spectrum of culprit foods, and more often used on-demand epinephrine.

CONCLUSIONS

The three phenotypes of allergic reactions to food and exercise differ in clinical characteristics, triggers, and response to treatment. Knowledge of these differences may help with patient education and counseling as well as disease management.

Skin Tests versus Serology: Specific IgE May Suffice for Diagnosis of Vespid Venom Allergy and Follow-Up of Allergen Immunotherapy

INTRODUCTION

In adults, allergic reactions to insect stings are among the most frequent causes of anaphylaxis, a potentially life-threatening condition. Recurrent anaphylaxis following vespid stings may be prevented by allergen immunotherapy (AIT). The aim of this study was to evaluate the benefit of measuring venom-induced wheal area in intracutaneous skin tests (ICT), in comparison to various serological and clinical parameters, for the diagnosis of severe vespid venom allergy and during follow-up of AIT.

METHODS

We conducted a monocentric, retrospective evaluation of 170 patients undergoing AIT against vespid venoms. We scanned ICT wheals at baseline and at three time points after AIT initiation and measured wheal area using objective data analysis software.

RESULTS

We found that ICT histamine-induced and venom-induced wheal areas did not correlate. In addition, the venom-induced wheal area was independent from the minimal venom concentration required to elicit a wheal in an ICT and all other parameters. No correlation was found between wheal area and the severity of anaphylaxis. Wheal area standardized to the application of 0.1 μg/mL venom inversely correlated with anaphylaxis severity and positively correlated with venom-specific IgE levels. During AIT, mean areas of venom-induced wheals did not change. In contrast, venom-specific IgG and IgG4 levels, and the minimal venom concentration required to induce a positive ICT result increased, while the venom wheal area standardized to 0.1 μg/mL venom application and specific IgE levels decreased over time.

CONCLUSION

Wheal area evaluation did not provide additional information over specific IgE analysis. We therefore recommend that ICTs are used only as a secondary measure for confirming serological test results.

Trends and Variation in Pediatric Anaphylaxis Care From 2016 to 2022

BACKGROUND

Variation in the use of treatments and hospitalization for anaphylaxis would suggest a lack of consensus in therapeutic approach.

OBJECTIVE

To evaluate trends and practice variation in the emergency department (ED) care of children with anaphylaxis in a large US cohort.

METHODS

We conducted a 48-site retrospective cohort study using the Pediatric Health Information System from January 2016 through September 2022. Children younger than 18 years with a primary diagnosis of anaphylaxis were included. Care trends were assessed using negative binomial regression modeling. Rates of medication use, hospitalizations, and revisits were reported as medians with interquartile ranges (IQRs).

RESULTS

There were 42,909 ED visits for anaphylaxis, with a 4.2% per-year increase in visit incidence (95% CI, 1.8-6.7) during the study period. The median hospitalization rate was 3.5% (IQR, 2.2-6.0), and the 3-day ED revisit rate was 0.6% (IQR, 0.4-0.9). The hospital-level median use of therapies included intramuscular epinephrine (55.3%; IQR, 50.1-59.9), systemic steroids (73.8%; IQR, 63.9-81.4), antihistamines (59.9%; IQR, 53.5-65.5), H2-receptor antagonists (56.8%; IQR, 42.3-66.2), bronchodilators (15.1%; IQR, 12.5-17.0), inhaled epinephrine (1.1%; IQR, 0.6-1.9), and fluid boluses (19.8%; IQR, 11.3-29.3). Severe reactions requiring intensive care unit admission (1.5%; IQR, 0.8-2.2), vasopressors (0.3%; IQR, 0.0-0.6), and intubation (0.2%; IQR, 0.0-0.3) were rare.

CONCLUSIONS

ED visits for anaphylaxis increased during the study period, but hospitalization rates were low. Substantial variation exists between EDs regarding the use of anaphylaxis therapies, supporting the need for future research to evaluate the efficacy of these medications.

Use of a Liver-Targeting Immune-Tolerogenic mRNA Lipid Nanoparticle Platform to Treat Peanut-Induced Anaphylaxis by Single- and Multiple-Epitope Nucleotide Sequence Delivery

While oral desensitization is capable of alleviating peanut allergen anaphylaxis, long-term immune tolerance is the sought-after goal. We developed a liver-targeting lipid nanoparticle (LNP) platform to deliver mRNA-encoded peanut allergen epitopes to liver sinusoidal endothelial cells (LSECs), which function as robust tolerogenic antigen-presenting cells that induce FoxP3+ regulatory T-cells (Tregs). The mRNA strand was constructed by including nucleotide sequences encoding for nonallergenic MHC-II binding T-cell epitopes, identified in the dominant peanut allergen, Ara h2. These epitopes were inserted in the mRNA strand downstream of an MHC-II targeting sequence, further endowed in vitro with 5' and 3' capping sequences, a PolyA tail, and uridine substitution. Codon-optimized mRNA was used for microfluidics synthesis of LNPs with an ionizable cationic lipid, also decorated with a lipid-anchored mannose ligand for LSEC targeting. Biodistribution to the liver was confirmed by in vivo imaging, while ELISpot assays demonstrated an increase in IL-10-producing Tregs in the spleen. Prophylactic administration of tandem-repeat or a combination of encapsulated Ara h2 epitopes induced robust tolerogenic effects in C3H/HeJ mice, sensitized to and subsequently challenged with crude peanut allergen extract. In addition to alleviating physical manifestations of anaphylaxis, there was suppression of Th2-mediated cytokine production, IgE synthesis, and mast cell release, accompanied by increased IL-10 and TGF-β production in the peritoneum. Similar efficacy was demonstrated during LNP administration postsensitization. While nondecorated particles had lesser but significant effects, PolyA/LNP-Man lacked protective effects. These results demonstrate an exciting application of mRNA/LNP for treatment of food allergen anaphylaxis, with the promise to be widely applicable to the allergy field.

Hymenoptera Venom Allergy and Anaphylaxis

Hymenoptera stings can induce allergic and occasionally fatal reactions, and are responsible for significant morbidity and deterioration in health-related quality of life. The diagnostic work-up must consider the medical history of patients, in the context of venom allergy epidemiology and Hymenoptera taxonomy, and the clinical manifestations of the reactions, to channel the available in vivo and in vitro tests towards the most accurate diagnosis and the consequent appropriate management, also considering the risk profile of the patients on a precision-medicine approach. All these aspects are covered by this work that aims at providing an up-to-date review to increase the awareness of this topic among interested stakeholders, like healthcare professionals and political decision makers, who can contribute to the proper immediate and long-term management of venom allergy and anaphylaxis.

[Anaphylaxis: an update]

Anaphylaxis is the most severe form of acute systemic allergic reaction and can be fatal in the absence of adequate treatment with adrenaline. We propose to review the different mechanisms underlying anaphylaxis, as well as the diagnostic criteria and its management regarding the 2020 guidelines of the World Allergy Organization (WAO).

Refractory Anaphylactic Shock Requiring Emergent Venoarterial Extracorporeal Membrane Oxygenation in the Emergency Department: A Case Report

Venoarterial extracorporeal membrane oxygenation is a viable salvage intervention for patients who experience cardiopulmonary arrest or profound shock from any cause. Acute anaphylactic shock is a rare cause of cardiac arrest. We present a case of a 35-year-old male who experienced cardiac arrest owing to anaphylactic shock while receiving general anesthesia for a routine outpatient surgical procedure. Traditional advanced cardiac life support therapies were provided by paramedics en route to the emergency department of a suburban, community-based hospital. Maximal medical management including endotracheal intubation, intravenous steroids, intravenous crystalloid fluid administration, intravenous vasoactive medications, and high-quality cardiopulmonary resuscitation was provided. Although return of spontaneous circulation was achieved, profound cardiogenic shock persisted. Venoarterial extracorporeal membrane oxygenation was initiated by the emergency department provider and nursing team. The patient survived, was neurologically intact, had full recovery, and was discharged home several days later. We have extensive experience with venoarterial extracorporeal membrane oxygenation, and this case exemplifies the value of an established emergency department extracorporeal membrane oxygenation program in managing all causes of cardiac arrest or refractory shock.

Food-Dependent Exercise-Induced Wheals, Angioedema, and Anaphylaxis: A Systematic Review

BACKGROUND

Food-dependent exercise-induced wheals, angioedema, and anaphylaxis remain insufficiently characterized.

OBJECTIVE

We systematically reviewed the literature on clinical manifestations, laboratory investigations, culprit foods, triggering exercise, comorbidities, and treatment outcomes.

METHODS

Using predefined search terms and Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) recommendations, we searched 3 electronic databases to identify relevant literature published before July 2021.

RESULTS

Of 722 patients (median age 25 years; 55.4% male) from 231 studies (43 cohort studies, 15 cases series, and 173 case reports), 79.6% and 3.7% had anaphylaxis with and without wheals and/or angioedema, respectively. The remaining 16.6% had wheals and/or angioedema without anaphylaxis. The duration from eating to exercising and from exercising to symptom onset ranged from 5 minutes to 6 hours (median 1 hour) and from 5 minutes to 5 hours (median 30 minutes), respectively, and virtually all patients exercised within 4 hours after eating and developed symptoms within 1 hour after exercising. Wheat was the most common culprit food. Running was the most common trigger exercise. Most patients were atopic, and 1 in 3 had a history of urticaria. Aspirin and wheat-based products were the most frequent augmenting factors. On-demand antihistamines, corticosteroids, and epinephrine were commonly used and reported to be effective. Patients who stopped eating culprit foods before exercise no longer developed food-dependent exercise-induced allergic reactions.

CONCLUSIONS

Food-dependent exercise-induced allergic reactions are heterogeneous in their clinical manifestations, triggers, and response to treatment. Patients benefit from avoidance of culprit foods before exercise, which highlights the need for allergological diagnostic workup and guidance.

Management of allergic reactions and anaphylaxis in the emergency department

An acute allergic reaction is a rapid-onset, IgE-mediated hypersensitivity reaction. Although it is most commonly caused by food, insect stings, and medications, there are many additional causes. Symptoms can range from mild urticaria and swelling, to abdominal cramping, to respiratory collapse. Anaphylaxis and anaphylactic shock are the most severe, life-threatening forms of allergic reaction, with fast onset and decompensation, requiring urgent airway monitoring and support. This issue reviews the current evidence on managing allergy and anaphylaxis with epinephrine, and reviews the evidence on corticosteroids, antihistamines, and other adjunctive therapies. Guidelines are reviewed to offer assistance with grading of symptoms, which can help determine treatment and disposition. Biphasic reactions and allergic reactions caused by alpha-gal, scombroid poisoning, and Kounis syndrome are also reviewed.

[Angioedema and anaphylaxis, a family story]

Non-allergic angioedema has a worrying morbidity. Clinical examination is central, as C1-esterase inhibitor deficiency will not be documented in the acute phase. In the case of anaphylaxis that does not respond to adrenaline, an early diagnosis can optimise referral of the patient to a reference healthcare establishment for a specific therapeutic protocol (icatibant, C1 inhibitor) recently updated by recommendations.

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).

[Path of a fighter]

Allergy is a frequent and often disabling condition for the patients. In the context of allergic rhinitis and asthma or anaphylactic shock to hymenoptera venom, allergenic desensitization can be proposed to limit the symptoms or recurrence of major reactions. Access to this treatment is made difficult by a lack of allergists, a lack of products or, more recently, by the Covid-19 crisis.

[CURRENT SITUATION OF ANAPHYLAXIS IN JAPAN: DATA FROM THE ANAPHYLAXIS REGISTRY OF TRAINING AND TEACHING FACILITIES CERTIFIED BY THE JAPANESE SOCIETY OF ALLERGY]

BACKGROUND

No nationwide epidemiological survey of anaphylaxis in Japan has been conducted. The aim of this study was to elucidate the triggers and treatment of anaphylaxis in Japan.

METHODS

We prospectively collected clinical information on the triggers and treatment of patients who developed anaphylaxis or were admitted to the emergency room with anaphylaxis in the training and teaching facilities of the Japanese Society of Allergology between February 2015 and October 2017.

RESULTS

Seventy-nine of 451 facilities (18%) participated in the study, and a total of 767 patients (under 18 years, 73%; in-hospital, 7%) were enrolled. The most common triggers were food (68%), drugs (12%), food-dependent exercise-induced anaphylaxis (5%), insects (4%), and oral immunotherapy (3%), with drugs being the most common in-hospital trigger and food being the most common out-of-hospital trigger. The intramuscular injection of adrenaline in medical institutions accounted for 38% of cases, 10% of which required multiple doses. The rate of use of adrenaline self-injections in out-of-hospital cases was 12%.

CONCLUSION

The present study revealed the most common triggers and treatment for anaphylaxis in Japan. Self-management at the onset of anaphylaxis and adrenaline administration as the initial treatment may be insufficient. Therefore, it is necessary to thoroughly instruct patients and educate physicians regarding anaphylaxis.

Anaphylaxis: Emergency Department Treatment

Anaphylaxis is a potentially life-threatening, multisystem allergic reaction that can cause airway, breathing, or circulatory compromise. Intramuscular epinephrine is the immediate treatment of all patients. Intravenous epinephrine should be used in patients in shock, either as a bolus or infusion, along with fluid resuscitation. Airway obstruction must be recognized, and early intubation may be necessary. For shock that is refractory to epinephrine, additional vasopressors may be needed. Disposition depends on patient presentation and response to treatment. Mandatory observation periods are not necessary, because biphasic reactions are difficult to predict and may occur outside of typical observation periods.

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.

Cardiopulmonary resuscitation in special circumstances

Cardiopulmonary resuscitation prioritises treatment for cardiac arrests from a primary cardiac cause, which make up the majority of treated cardiac arrests. Early chest compressions and, when indicated, a defibrillation shock from a bystander give the best chance of survival with a good neurological status. Cardiac arrest can also be caused by special circumstances, such as asphyxia, trauma, pulmonary embolism, accidental hypothermia, anaphylaxis, or COVID-19, and during pregnancy or perioperatively. Cardiac arrests in these circumstances represent an increasing proportion of all treated cardiac arrests, often have a preventable cause, and require additional interventions to correct a reversible cause during resuscitation. The evidence for treating these conditions is mostly of low or very low certainty and further studies are needed. Irrespective of the cause, treatments for cardiac arrest are time sensitive and most effective when given early-every minute counts.

Factors influencing emergency department observation time following anaphylaxis: a systematic review

OBJECTIVE

Anaphylaxis is a condition that warrants an observation period after symptoms resolution to detect rare but life-threatening delayed complications. There is a need for evidence to identify patients who would benefit from prolonged observation time. The purpose of this review was to identify factors that may influence the need for longer observation in the emergency department.

METHODS

PubMed, Embase, EBM Review, and Cochrane Library were searched using controlled vocabulary and keywords to cover all relevant data. Titles, abstract, and full text were reviewed for inclusion and exclusion criteria. Data were extracted from the included articles regarding case definitions, prognosis, treatment and time factors, and recommended observation time. Factors linked to observation time or complications were tabulated and compared between studies.

RESULTS

The search retrieved 2443 citations of which 49 were included. Twenty-one were primary studies and were used to identify factors influencing observation time or complications. Biphasic anaphylaxis was the only adverse event that warranted prolonged observation. The five risk factors often associated with biphasic reactions were time to first epinephrine, history of anaphylaxis, symptom severity, number of epinephrine doses, and unknown trigger. Biphasic reactions happened mostly within the first 72 h with most severe reactions occurring earlier than the milder ones. Heterogeneity in the definition of biphasic anaphylaxis made comparisons challenging.

CONCLUSIONS

Observation time should be based on the provider's best estimation of the risk of biphasic anaphylaxis, although no single factor can predict their occurrence. The identified factors will allow the development of an early discharge screening tool.

Adverse reactions to COVID-19 vaccines: A practical approach

COVID-19-related mortality in high-risk individuals is substantial and current treatment options are limited. There is convincing evidence that the COVID-19 vaccines reduce the severity of infection and prevent deaths. Three COVID-19 vaccines are approved in the United Kingdom with many more in development. There are limited data on the triggers and mechanisms of anaphylaxis to these vaccines. We review the potential allergenic compounds in the COVID-19 vaccines and describe an innovative allergy support model for the vaccination hubs that allows most patients with severe allergy be immunized. Finally, we propose a practical algorithm for the investigations of anaphylaxis to these vaccines.

Anaphylaxis following rivaroxaban ingestion: report of an extremely rare case

We reported an anaphylactic reaction following ingestion of rivaroxaban in a 48-years-old male, who was recently discharged from the hospital as a case of deep vein thrombosis. At home, the patient developed a diffuse itchy skin rash, shortness of breath, and vomiting 30 minutes after rivaroxaban ingestion. Emergency Medical Service found that the patient had severe dyspnea, low blood pressure, and decreased blood oxygen saturation. The patient was given oxygen, intramuscular epinephrine, intravenous hydrocortisone, diphenhydramine, salbutamol nebulizer, and was immediately transferred to the emergency department of Hamad General Hospital. Subcutaneous enoxaparin was initiated, while hydrocortisone and salbutamol nebulizer continued. On the next day, his vital signs had stabilized, and intravenous hydrocortisone was switched to prednisolone tablets, and salbutamol nebulizer was switched to budesonide/salmeterol inhaler, whereas enoxaparin was overlapped with warfarin. After achieving the target international normalized ratio (INR), enoxaparin was discontinued and the patient was discharged with significant clinical and laboratory improvement.

Time Course and Management of Protracted Anaphylaxis Due to PEG-Asparaginase

Polyethylene glycosylated (PEG)-asparaginase is a cornerstone of treatment for acute lymphoblastic leukemia (ALL), and effective administration is associated with better outcomes. PEG-asparaginase is associated with a uniphasic hypersensitivity reaction in ∼10% to 20% of patients. We present a 17-year-old male individual diagnosed with very high-risk pre-B-ALL, who experienced protracted anaphylaxis 1 hour following administration of his second PEG-asparaginase dose. This type of allergic reaction has yet to be described in ALL patients treated with PEG-asparaginase. Here, we outline the time course and successful management of protracted anaphylaxis in an ALL patient.

Idiopathic Anaphylaxis: a Perplexing Diagnostic Challenge for Allergists

PURPOSE OF REVIEW

The aim of this systematic review is to present the proposed theories of pathogenesis for idiopathic anaphylaxis (IA), to discuss its classification, its diagnostic approach, and management.

RECENT FINDINGS

IA represents a major diagnostic challenge and is diagnosed when excluding the possible identifiable triggers of anaphylaxis. The current research, however, revealed that certain conditions including mastocytosis, mast cell activation syndromes, and hereditary alpha tryptasemia can masquerade and overlap with its symptomatology. Also, newly identified galactose-alpha-1,3-galactose mammalian red meat allergy has recently been recognized as underlying cause of anaphylaxis in some cases that were previously considered as IA. IA comprises a heterogenous group of conditions where, in some cases, inherently dysfunctional mast cells play a role in pathogenesis. The standard trigger avoidance strategies are ineffective, and episodes are unpredictable. Therefore, prompt recognition and treatment as well as prophylaxis are critical. The patients should always carry an epinephrine autoinjector.

Approach to Perioperative Anaphylaxis in 2020: Updates in Diagnosis and Management

PURPOSE OF REVIEW

The goal of the paper is to review the epidemiology, pathogenesis, diagnosis, and manifestations of perioperative anaphylaxis (POA). We seek to review the most common culprits of POA and different diagnostic modalities for evaluation.

RECENT FINDINGS

Specific IgE testing has a limited role in POA evaluation due to lack of widespread availability and low sensitivity. Basophil activation testing is complementary to skin tests and can assist NMBA sensitivity diagnosis in complex cases. In the past years, there has been an exponential increase in suspected teicoplanin allergic reactions in the European Union. Chlorhexidine is also being increasingly implicated as a culprit in POA. Multiple classes of perioperative medications cause POA. Diagnostic modalities available include skin testing with nonirritating concentrations, basophil activation tests, specific IgE, and drug provocation testing. An accurate record and critical analysis of perioperative events is more important than isolated test results. Future studies evaluating the pathophysiology of these reactions and other therapeutic strategies, such as targeting the MRGPRX2 receptor, are needed.