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Background: Anaphylaxis is a severe systemic hypersensitivity reaction that usually has a rapid onset and can be fatal. Presentations of childhood anaphylaxis vary widely in accordance with the triggers and the patient's age, geographical region and dietary and lifestyle habits., Methods: The medical records of 177 paediatric patients diagnosed with anaphylaxis between January 2021 and January 2024, whose disease progression was monitored at a single tertiary care centre, were reviewed retrospectively., Results: The study included 177 patients diagnosed with anaphylaxis (107 males and 70 females with a median age of 48 months). The most common allergen responsible was food (53.7%). Egg allergy was the most common source of anaphylaxis, afflicting 35 patients (19.3%), while beta-lactam provoked the most common drug allergy, affecting 24 patients (13.6%). The most common organ involved was the skin (92.7%). When the patients were analysed by age group, there were more males in the infancy, preschool and school age groups, while there were more females in the adolescent group (p = 0.44). Food-induced anaphylaxis became less common with increasing age, whereas the rate of drug-induced anaphylaxis increased (p = 0.01 and p = 0.01, respectively). Cardiovascular system findings were observed more frequently in adolescents compared to other age groups (p = 0.003). Most cases stemming from a food allergy were mild, whereas most drug-induced cases were moderate or severe (p < 0.05). When severity was analysed by age group, mild cases in infants were more common than moderate to severe cases., Conclusion: The aetiological and clinical manifestations of childhood anaphylaxis vary among different age groups., Competing Interests: The authors declare no conflict of interest.

In this cross-sectional, descriptive, and observational study conducted at Fundación Valle del Lili in Colombia, the clinical and sociodemographic characteristics of anaphylaxis were investigated in a cohort of 80 patients who sought medical care between January 2021 and December 2022. With a median age of 16 years and a notable prevalence among individuals aged below 18 years, the study revealed that 63.8% of patients had concomitant allergic diseases. Medications emerged as the primary triggers for anaphylaxis, followed by food. The mucocutaneous system was predominantly affected in 55% of cases, with respiratory involvement observed in 37.5%. Alarmingly, anaphylactic shock occurred in 17.5%, and 7.5% experienced biphasic anaphylaxis. Intramuscular adrenaline was administered in 88.8% of cases, with 75% of patients not receiving an allergy consultation upon discharge, and 52.5% lacking follow-up for allergy care. Considering that in Colombia epidemiological data on the clinical and sociodemographic aspects of anaphylaxis remain largely unknown, this study documents the features of anaphylaxis in both adult and pediatric populations and highlights the urgent need for improved awareness, timely evaluation by allergists, and comprehensive follow-up care for individuals experiencing anaphylaxis., Competing Interests: The authors state no conflict of interest.

Background: Estimates for the prevalence of food allergy vary widely, with a paucity of data for adults. The aim of this analysis was to report trends in the incidence and prevalence of food allergy in England, using a national primary care dataset., Methods: We analysed data from Clinical Practice Research Datalink between 1998 and 2018, with linked data to relevant hospital encounters in England. The main outcomes were incidence and prevalence of food allergy, according to three definitions of food allergy: possible food allergy, probable food allergy, and probable food allergy with adrenaline autoinjectors prescription. We also evaluated the difference in proportion of patients prescribed adrenaline autoinjectors by English Index of Multiple Deprivation (IMD), age, and by previous food anaphylaxis, and explored differences in patient encounters (general practice vs emergency department setting)., Findings: 7 627 607 individuals in the dataset were eligible for inclusion, of whom 150 018 (median age 19 years [IQR 4-34]; 82 614 [55·1%] female and 67 404 [44·9%] male) had a possible food allergy. 121 706 met diagnostic criteria for probable food allergy, of whom 38 288 were prescribed adrenaline autoinjectors. Estimated incidence of probable food allergy doubled between 2008 and 2018, from 75·8 individuals per 100 000 person-years (95% CI 73·7-77·9) in 2008 to 159·5 (156·6-162·3) individuals per 100 000 person-years in 2018. Prevalence increased from 0·4% (23 399 of 6 432 383) to 1·1% (82 262 of 7 627 607) over the same period and was highest in children under 5 years (11 951 [4·0%] of 296 406 in 2018) with lower prevalence in school-aged children (from 11 353 [2·4%] of 473 597 in 2018 for children aged 5-9 years to 6896 [1·7%] of 404 525 for those aged 15-19 years) and adults (42 848 [0·7%] of 5 992 454 in 2018). In those with previous food anaphylaxis, only 2321 (58·3%) of 3980 (975 [64·0%] of 1524 children and young people and 1346 [54·8%] of 2456 adults) had a prescription for adrenaline autoinjector. Adrenaline autoinjectors prescription was less common in those resident in more deprived areas (according to IMD). In the analysis of health-care encounters, 488 604 (97·1%) of 503 198 visits recorded for food allergy occurred in primary care, with 115 655 (88·4%) of 130 832 patients managed exclusively in primary care., Interpretation: These estimates indicate an important and increasing burden of food allergy in England. Our findings that most patients with food allergy are managed outside the hospital system, with low rates of adrenaline autoinjector prescription in those with previous anaphylaxis, highlight a need to better support those working in primary care to ensure optimal management of patients with food allergy., Funding: UK Food Standards Agency and UK Medical Research Council., Competing Interests: Declaration of interests PJT reports grants from JM Charitable Foundation, National Institute for Health and Care Research (NIHR)–Imperial Biomedical Research Centre, and End Allergies Together, outside the submitted work; and personal fees from UK Food Standards Agency, DBV Technologies, Aimmune Therapeutics, Allergenis, and ILSI Europe outside the submitted work. AC reports personal fees from Novartis, Sanofi, Stallergenes Greer, AstraZeneca, GSK, and La Roche-Posay, outside the submitted work. JKQ reports grants from Medical Research Council, Health Data Research UK, GSK, Boehringer Ingelheim, Asthma + Lung UK, and AstraZeneca outside the submitted work; and personal fees from GSK, Evidera, AstraZeneca, and Insmed. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: Food allergies, particularly peanut, represent the predominant cause of anaphylaxis. Whereas early allergen introduction has emerged as a potential preventive strategy, the precise impact of recent guidelines on peanut-induced anaphylaxis rates in Canada remains unclear., Objective: To assess the impact of the 2017 Addendum Guidelines for the Prevention of Peanut Allergy on peanut-induced anaphylaxis rates in Canada., Methods: Using a comprehensive longitudinal registry capturing pediatric anaphylaxis presentations to the Montreal's Children's Hospital, we compared children with and without known peanut allergy who presented with peanut-induced anaphylaxis between 2011 and 2019 inclusive, excluding data beyond 2019 owing to the Coronavirus disease 2019 (COVID-19) pandemic. We calculated rates of peanut-induced anaphylaxis presentations per 100,000 age-adjusted all-cause emergency department visits using 4-month intervals. Interrupted time series analysis was used to compare anaphylaxis rate trends before and after 2017 for children ages 0 to 2 and 3 to 17 years., Results: We examined 2,011 cases of pediatric anaphylaxis, including 429 (21%) triggered by peanuts. Compared with pre-guideline estimates, the yearly rate of change of peanut anaphylaxis rates decreased by 7.96 (95% confidence interval -14.57 to -1.36; P = .018) after 2017 among patients with new-onset anaphylaxis in children 2 years of age or younger (n = 109). No significant changes were identified for older patients ages 3 to 17, or in patients with known peanut allergy., Conclusions: Early introduction guidelines in Canada are associated with a reduced risk of new-onset peanut-induced anaphylaxis in young children within a single center in Montreal. Further research is required to assess the impact on a wider population and other food allergens., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose of Review: Buckwheat (BW) allergy is a significant issue in Asia. This review delves into three types of BW allergy: immediate food allergy; food-dependent, exercise-induced anaphylaxis (FDEIA) as a subset of immediate food allergy; and food protein-induced enterocolitis syndrome (FPIES); by comparing data from Asian and non-Asian countries., Recent Findings: Most studies on BW have been published in Japan and Korea, and only a few studies on the topic have been done outside Asia. To date, seven components of common BW (Fagopyrum esculentum) and four components of Tartary BW (Fagopyrum tartaricum) have been implicated in BW allergy. Although BW-sIgE has limited utility for evaluating immediate BW allergy, Fag e 3-specific IgE, one of the components of common BW, and the skin prick test are diagnostically useful. The present review aims to shed light on the current state of knowledge, highlight research gaps, and suggest future directions in the management and understanding of BW allergy., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Anaphylaxis can lead to a life-threatening situation. Therefore, rapid diagnosis and emergency treatment is indicated. Immediate treatment with intramuscular adrenaline (or intravascularly with sufficient medical expertise) in anaphylaxis with cardiovascular and/or respiratory symptoms is recommended by various guidelines. Previous studies have shown that anaphylaxis is often not treated according to guidelines and that adrenaline in particular is rarely administered., Objective: The aim of the study was to investigate the data on emergency treatment and outcomes of patients with anaphylaxis by the air rescue and ground-based emergency services Dresden. Moreover, the results of the air- and ground-based services were compared. The focus was on administration of adrenaline and outcomes., Materials and Methods: Data from the ground-based emergency service Dresden (from 2012 to 2016) and the air rescue service Dresden (from 2008 to 2015) related to anaphylactic reactions were analyzed retrospectively. The severity of the anaphylaxis, the emergency medication administered, further monitoring, and outcomes were analyzed., Results: Data from 152 adults/29 children were analyzed for air rescue and 1131 adults/223 children for the ground-based emergency service. Adults with grade II-IV anaphylaxis received adrenaline in 19% (air rescue) and 7% (ground rescue) of cases. Children with grade II-IV anaphylaxis received adrenaline in 7% (air rescue) and 8% (ground rescue) of cases. Immediate drug therapy led to an improvement in general condition in 96-98% (air rescue) and 72-77% (ground-based emergency service) of cases. A significant correlation was found between the administration of adrenaline and the improvement in outcome in the ground-based emergency cohort., Conclusion: Guideline-compliant first-line therapy with adrenaline was not performed in the majority of the cases analyzed in this study. The significant effect of adrenaline on outcome demonstrated in this study emphases the need to improve the emergency treatment of anaphylactic reactions., (© 2024. The Author(s).)

Purpose: Acute allergic reactions may occur in susceptible individuals following exposure to various allergens. Obesity is linked to allergic reactions, and weight loss from bariatric surgery may attenuate the severity of certain conditions such as airway hyperresponsiveness in asthma. This retrospective observational study investigates associations between prior bariatric surgery and lower risk for life-threatening conditions in patients hospitalized with acute allergic reactions and anaphylaxis., Materials and Methods: Adults ≥ 18 years old diagnosed with morbid obesity and admitted to US hospitals with acute allergic reactions/anaphylaxis were included. All data were extracted from the US Nationwide Inpatient Sample (NIS) database 2005-2018. Patients without information on in-hospital mortality, discharge destination, hospital costs, and length of stay (LOS) were excluded. Patients were divided into two groups based on prior bariatric surgery or not. All diagnoses were verified through ICD-9 and ICD-10 codes. Between-group differences and associations between variables were evaluated using logistic regression analysis., Results: After matching, patients with prior bariatric surgery had significantly lower proportions of any life-threatening morbidity (37.2% vs. 47.4%), respiratory distress or failure (11.2% vs. 17.0%), pneumonia or severe infection (7.4% vs. 10.2%), sepsis/septic shock (15.2% vs. 20.9%), intubation and mechanical ventilation (11.2% vs. 14.6%), prolonged LOS (10.3% vs. 20.6%) and unfavorable discharge (6.9% vs. 12.5%) than those without prior bariatric surgery., Conclusion: Prior bariatric surgery predicts a lower risk of life-threatening morbidity and prolonged LOS among adults hospitalized for acute allergic reaction and anaphylaxis. Future prospective studies are warranted to confirm the present findings and reveal underlying mechanisms., (© 2024. The Author(s).)

Background: Perioperative anaphylaxis is a serious and often life-threatening immediate hypersensitivity reaction. There are few published data on paediatric perioperative anaphylaxis (pPOA). We evaluated the incidence of and risk factors involved in the occurrence of pPOA within a large US national database., Methods: Deidentified data from the US Nationwide Inpatient Sample from 2005 to 2014 were used to identify pPOA cases and to conduct a retrospective multivariate analysis of preselected independent variables., Results: Among 3,601,180 surgeries and procedures in children aged 0-18 yr, 297 pPOA cases were identified for an incidence of one in 12,125 surgeries and procedures. Compared with controls, pPOA cases had an increased median length of stay (6 vs 2 days; P<0.001) and median hospital cost ($54 719 vs $5109; P<0.0001). The age groups between 6 and 12 yr (odds ratio [OR] 7.1; 95% confidence interval [CI] 3.9-12.9; P<0.001) and 13 and 17 yr (OR 8.5; 95% CI 4.7-15.2; P<0.001) were associated with increased odds of pPOA. Transplant (OR 46.3; 95% CI 20.8-102.9; P<0.001), cardiac (OR 16.4; 95% CI 7.5-35.9; P<0.001), and vascular (OR 15.2; 95% CI 7.5-30.7; P<0.001) procedures posed the highest risk for pPOA. Chronic pulmonary disease, coagulopathy, and fluid and electrolyte disorders were also associated with pPOA (OR 2.2; 95% CI 1.5-3.3; P<0.001)., Conclusions: The incidence of pPOA was one in 12,125 cases. Risk factors included age, procedure type, and comorbidities., (Copyright © 2024 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: Food-induced anaphylaxis (FIA) is a major public health problem resulting in serious clinical complications, emergency department visits, hospitalization, and death., Objective: This study aims to assess the epidemiology and the trends in hospitalizations because of FIA in Spain between 2016 and 2021., Methods: An observational descriptive study was conducted using data from the Spanish National Hospital discharge database. Information was coded based on the International Classification of Diseases, Tenth Revision. The study population was analyzed by gender and age group and according to food triggers, clinical characteristics, admission to the intensive care unit, severity, and in-hospital mortality. The annual incidence of hospitalizations because of FIA per 100,000 person-years was estimated and analyzed using Poisson regression models. Multivariable logistic regression models were constructed to identify which variables were associated with severe FIA., Results: A total of 2161 hospital admissions for FIA were recorded in Spain from 2016 to 2021. The overall incidence rate was 0.77 cases per 100,000 person-years. The highest incidence was found in those aged <15 years (3.68), with lower figures among those aged 15 to 59 years (0.25) and ≥60 years (0.29). Poisson regression showed a significant increase in incidence from 2016 to 2021 only among children (3.78 per 100,000 person-years vs 5.02 per 100,000 person-years; P=.04). The most frequent food triggers were "milk and dairy products" (419/2161, 19.39% of cases) and "peanuts or tree nuts and seeds" (409/2161, 18.93%). Of the 2161 patients, 256 (11.85%) were hospitalized because FIA required admission to the intensive care unit, and 11 (0.51%) patients died in the hospital. Among children, the most severe cases of FIA appeared in patients aged 0 to 4 years (40/99, 40%). Among adults, 69.4% (111/160) of cases occurred in those aged 15 to 59 years. Multivariable logistic regression showed the variables associated with severe FIA to be age 15 to 59 years (odds ratio 5.1, 95% CI 3.11-8.36), age ≥60 years (odds ratio 3.87, 95% CI 1.99-7.53), and asthma (odds ratio 1.71,95% CI 1.12-2.58)., Conclusions: In Spain, the incidence of hospitalization because of FIA increased slightly, although the only significant increase (P=.04) was among children. Even if in-hospital mortality remains low and stable, the proportion of severe cases is high and has not improved from 2016 to 2021, with older age and asthma being risk factors for severity. Surveillance must be improved, and preventive strategies must be implemented to reduce the burden of FIA., (©Rodrigo Jimenez-Garcia, Ana Lopez-de-Andres, Valentin Hernandez-Barrera, Jose J Zamorano-Leon, Natividad Cuadrado-Corrales, Javier de Miguel-Diez, Jose L del-Barrio, Ana Jimenez-Sierra, David Carabantes-Alarcon. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 27.08.2024.)

Background: There has been limited data regarding the incidence of anaphylaxis in Asia. We aim to describe patterns in patient characteristics, triggers and clinical presentation of childhood anaphylaxis in Singapore., Methods: This was a retrospective review of emergency electronic medical records of children with anaphylaxis. Patients with the allergy-related diagnoses of anaphylaxis, angioedema, allergy and urticaria based on ICD-9 codes were screened. Cases fulfilling the World Allergy Organization criteria for anaphylaxis were included., Results: A total of 1188 cases of anaphylaxis were identified with a median age of 6.3 years. Extrapolating data from the study sites, from 2015 to 2022, the incidence rate of childhood anaphylaxis emergency visits in Singapore doubled from 18.9 to 38.8 per 100,000 person-years, with an incidence rate ratio (IRR) of 2.06 (95% confidence interval [CI] 1.70-2.49). In 2022, the incidence rate of food anaphylaxis was 30.1 per 100,000 person-years, IRR 2.39 (95% CI 1.90-3.01) and drug anaphylaxis was 4.6 per 100,000 person-years, IRR 1.89 (95% CI 1.11-3.25). The incidence rate in children aged 0-4 years quadrupled during the study period. Common triggers were egg (10.4%), peanut (9.3%), tree nut (8.8%), milk (8%), shellfish (7.8%) and non-steroidal anti-inflammatory drug (4.4%). The majority (88.6%) of patients were treated with intramuscular adrenaline. Total number of allergy-related visits did not increase over time between 2015 and 2019. Rates of severe anaphylaxis, namely anaphylactic shock and admission to high-dependency and intensive care, did not increase over time, with a mean incidence of 1.6, IRR 0.85 (95% CI 0.40-1.83) and 0.7, IRR 1.77 (95% CI 0.54-5.76) per 100,000 person-years, respectively., Conclusion: While the number of emergency visits due to childhood anaphylaxis has increased, the number of cases of allergy-related visits, anaphylactic shock and anaphylaxis requiring high-dependency and intensive care did not rise., (© 2024 John Wiley & Sons Ltd.)

Activating mutations in KIT , particularly D816V, have been associated with mastocytosis. Additionally, expression of heterozygous KIT M541L has been primarily reported in patients with pediatric mastocytosis. We thus examined the prevalence of this variant in pediatric and adult patients with mastocytosis ( n = 100) compared to ancestry-matched 1000 genomes controls ( n = 500) and patients with idiopathic anaphylaxis ( n = 23). We then compared clinical symptoms and laboratory data on patients with systemic and cutaneous mastocytosis and bone marrow histopathology on a matched cohort with and without the KIT M541L variant. Overall, the KIT M541L variant was identified in 19 individuals; the majority were diagnosed with systemic mastocytosis (89.4%) with an associated KIT D816V mutation. There were no significant differences in peripheral blood parameters between groups. Patients with mastocytosis carrying the KIT M541L variant did not demonstrate significant differences in symptomatology compared to a matched reference cohort ( n = 13/81) without KIT M541L. In patients with idiopathic anaphylaxis, no significant associations were observed. This study uniquely examines the prevalence and impact of the KIT M541L variant in both adult and pediatric patients with mastocytosis further stratified by disease variant. To our knowledge, this is the first case/control study to show a significant genetic association with mastocytosis at the KIT M541L locus.

Background: Anaphylaxis is a common feature of patients with mastocytosis, particularly with Hymenoptera venoms. Hence, it is hypothesized that patients with mastocytosis may have an increased susceptibility to developing drug-induced anaphylaxis (DIA). Patients and medical practitioners are therefore concerned when there is a need to use various drugs. However, this issue has not been systematically investigated., Objective: To investigate the prevalence and clinical characteristics of anaphylaxis to various types of drugs among patients with mastocytosis., Methods: A retrospective study was conducted among 470 consecutive patients (18 years and older) with confirmed clonal mast cell diseases recruited from 2 independent mastocytosis reference centers. All patients underwent a comprehensive, individualized allergy workup with evaluation of the (self)reported drug hypersensitivity., Results: The overall prevalence of DIA was 6.3%, accounting for one-third of the confirmed drug hypersensitivity reactions. Nonsteroidal anti-inflammatory drugs were the most common elicitors of DIA (56%), followed by perioperative agents (23%) and antibiotics (13%). Anaphylactic reactions were severe in most cases, with 43% of patients experiencing hypotensive syncope. All drug-related hypersensitivity reactions occurred before mastocytosis was diagnosed., Conclusions: The prevalence of DIA in mastocytosis tends to be higher than in the general population, but is overall low. However, its severity is more pronounced. Our results suggest that patients with mastocytosis with a previous reaction to drugs should undergo a thorough allergy workup. Well-tolerated drugs can be further used without specific precautions., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Fruit allergy usually presents with mild-to-moderate symptoms but serious systemic reactions, e.g., anaphylaxis, may also occur. Objective: This study aimed to examine the clinical and laboratory characteristics of patients with fruit allergy and fruit-induced anaphylaxis. Methods: Patients diagnosed with fruit allergy at Dışkapı Hematology and Oncology Hospital and Bilkent City Hospital between January 2017 and January 2023 were included in the study. The diagnosis of anaphylaxis was made according to the European Allergy and Clinical Immunology Anaphylaxis Guideline. Results: During the study period, skin-prick tests with food allergens were performed on 9432 patients in our clinic, and fruit allergy was detected in 78 patients (0.82%). Five patients with inaccessible medical records were excluded from the study. 40 (54.8%) were boys. The median (interquartile range) age at the onset of symptoms was 72 months (12.5-144 months). Sixty-eight of the patients (93.2%) had a concomitant allergic disease, the most common of which was allergic rhinitis ( n = 48 [65.8%]). The 73 patients had a history of reaction to 126 fruits. Twenty-five patients (19.8%) were allergic to multiple fruits. The most common fruit allergen was banana (22/126 [17.4%]), followed by peach (18/126 [14.2%]) and kiwi (17/126 [13.5%]). Mucocutaneous findings were observed most frequently after fruit consumption (120/126 [95.2%]). Anaphylaxis occurred in 17 patients (23.2%) with 21 fruits.The fruits most commonly associated with anaphylaxis were banana (6/21 [28.6%]) and kiwi (6/21 [28.6%]). Conclusion: Fruit allergy generally presents with mild symptoms, e.g., oral allergy syndrome, but severe systemic symptoms, e.g., anaphylaxis, can also be observed. Kiwi and banana are the fruits that most commonly cause anaphylaxis. Although more comprehensive studies are needed to comment on the development of tolerance, especially in patients with anaphylaxis, responsible fruit avoidance is still the most important strategy.

Background: While food allergy (FA) has been increasingly recognized as a growing public health burden worldwide, epidemiological studies on FA in Japan are limited., Methods: This was a noninterventional, observational study using the administrative claims data from 2010 to 2019 (10 years). Patients with physician-diagnosed FA in Japan (prevalent cohort) were divided into high-risk or low-risk cohorts using adrenaline prescription. The high-risk cohort was further divided into anaphylaxis or nonanaphylaxis cohort based on the occurrence of anaphylaxis or a serious allergic reaction (SAR) during 1 year after adrenaline prescription. The primary objective was to examine yearly prevalence of FA. The secondary objectives were to describe demographics/clinical characteristics and healthcare resource utilization (HCRU), to evaluate the number of occurrences of anaphylaxis/SAR in the high-risk cohort, and the impact of anaphylaxis/SAR on HCRU., Results: The overall standardized prevalence rate was 0.325% (95% confidence interval [CI], 0.311-0.339) in 2010 and 0.797% (95% CI, 0.790-0.804) in 2019 and predominant in patients age <6 years (preschool; 3.377% [95% CI, 3.229-3.525] in 2010 and 5.726% [95% CI, 5.663-5.789] in 2019). Majority of FA patients (>80%) were children/adolescent throughout the 10 years. While high-risk cohort was a relatively minor population (8.5% in the prevalent cohort in 2019), the occurrence of anaphylaxis/SAR in the high-risk cohort was 227,690/100,000 patient-years. Multivariate analysis showed a significant increase in HCRU variables in the anaphylaxis versus nonanaphylaxis cohort (e.g., 2.08 [95% CI, 2.05-2.11] times more FA-related outpatient visits)., Conclusions: Prevalence of FA increased in a statistically significant way from 2010 to 2019; 1.7-fold increase was observed in patients <6 years old. Patients in the high-risk cohort appear to have suffered from frequent anaphylaxis/SAR, highlighting an unmet medical need for FA patients at "high-risk," considering the unavailability of approved medications to prevent anaphylaxis/SAR., (© 2024 The Author(s). Pediatric Allergy and Immunology published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Objective: To determine the features, rescue measures, outcomes, re-allergic reactions, and independent risk factors associated with severe anaphylaxis during surgery., Design: Instances of severe perioperative anaphylaxis were identified through perioperative electronic records, adverse event reporting records, and surveys of anesthesiologists. Confirmed cases were randomly matched 4:1 with control cases on the same operation day. Patient risk factors, surgery type, anesthetic technique, and perioperative medications, fluids, and blood transfusions were given in instances of severe perioperative anaphylaxis were compared with control cases., Setting: A tertiary hospital in China., Patients: All patients undergoing surgery and anesthesia in the operating room from January 2014 to February 2022., Measurements: Incidence and the independent risk factors for severe perioperative anaphylaxis., Main Results: Ninety-seven patients experienced severe perioperative allergic responses during the 266,033 surgeries performed, with an incidence rate of 3.6 per 10,000. Three of 97 anaphylaxis patients experienced a severe allergic reaction again during the second surgery. The nested case-control study revealed that the independent triggers during surgery were allergy history (odds ratio 5.23; 95% confidence interval [CI], 2.35-11.68; p < 0.001), cisatracurium use (odds ratio 5.03; 95% CI, 1.22-20.70; p < 0.001), hydroxyethyl starch 130/0.4 use (odds ratio 5.36; 95% CI, 2.99-9.60; p =0.025), and allogeneic plasma (odds ratio 11.02; 95% CI, 3.78-35.95; p < 0.001)., Conclusions: Perioperative severe anaphylaxis is a rare but life-threatening complication. Previous allergic history, cisatracurium, hydroxyethyl starch 130/0.4, and allogeneic plasma may be the independent triggers. Early diagnosis of anaphylaxis and the timely administration of epinephrine are critical to allergic treatment. Avoiding exposure to allergens is effective for preventing severe allergic responses and the efficacy of glucocorticoids and antihistamines is controversial., Competing Interests: Declaration of competing interest All authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Purpose of Review: Epinephrine is the first line treatment for anaphylaxis, however, there are limited data to support this. This review examines data surrounding evidence for the use of epinephrine in anaphylaxis, data on prescription for and use of epinephrine autoinjectors, and data examining newer routes of delivery of epinephrine; with a focus on recent publications over the past few years., Recent Findings: With recent epidemiologic studies of anaphylaxis and new forms of epinephrine being studied, new data on the effects of epinephrine are aiding in the understanding of epinephrine's effects and the shortcomings of epinephrine both in its effect and utility in the real world., Summary: Epinephrine is still considered the first line therapy for anaphylaxis, and we are starting to have a better understanding of its effects in both healthy patients and those with anaphylaxis., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: This review will identify and summarize the published existing data pertaining specifically to Hymenoptera venom allergy in children and adolescents, highlighting the major studies currently available on venom immunotherapy (VIT) and its prognosis in children., Recent Findings: The current review covers the incidence and prevalence of Hymenoptera venom allergy (HVA) in children, factors influencing occurrence and severity of reactions (age, sex, comorbidities, etc.), indications to perform diagnostic tests and start VIT in children, different existing VIT protocols and their safety and efficacy., Summary: Hymenoptera venom allergy is the second most common cause of anaphylaxis in children and it considerably affects quality of life. Cutaneous reactions are the most prevalent clinical presentation in children who usually have a more favourable prognosis than adult patients. However, studies on HVA in children and adolescents are still limited. Currently VIT is the only treatment able to modify the natural history of HVA in adults as well as in children, and to protect patients from systemic reactions after subsequent stings., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: Adult food allergy, either unresolved from childhood, or new-onset in adult-life, is known to be increasingly prevalent. Although much of the reported anaphylaxis in adults is due to drug reactions, foods are becoming an increasingly important trigger, affecting adults of all ages, with a wide variation in food triggers which are often quite different to those reported in children., Recent Findings: Peanuts are well known to cause anaphylaxis in some adult populations, but other legumes such as soy may be more relevant in others. Reactions to natto, fermented soybeans, are currently mainly reported in Japan, but changing dietary practices and an increase in plant-based eating mean natto, other forms of soy and other legumes are increasingly linked to anaphylaxis in Western countries. Anaphylaxis to red meat, caused by sensitization to galactose-α-1,3-galactose and first reported in North America, is now a more world-wide concern. Co-factor induced anaphylaxis is increasingly associated with both wheat allergy and lipid transfer protein allergy., Summary: More research is urgently needed to characterize adult food allergy, its triggers and symptom severity. Unusual food triggers and potential co-factors should be considered, so that anaphylaxis in adults can be correctly managed, not merely labelled as idiopathic., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: The goal of this review is to summarize the potential causes of anaphylaxis in the different holiday contexts, providing practical suggestions aimed to mitigate the stress challenged by allergic patients because of unfamiliar situations., Recent Findings: A regard was reserved to potential food triggers, particularly uncommon ones and typical of certain destinations, and to arthropods responsible for anaphylaxis., Summary: This review highlights the potential risk of anaphylaxis due to the unusual contexts more experienced during holidays (i.e., travels, outdoor activities and eating out). Moreover, it underlines the need for a further allergological education in these cases, in order to prepare allergic patients to avoid and manage undesired situations., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

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], 11β-prostaglandin-F 2α [11β-PGF 2α ], leukotriene E 4 [LTE 4 ]) 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: 11β-PGF 2α ratio > 1.6, N-MH ratio >1.7, and LTE 4 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 (11β-PGF 2α ratio >1.6, N-MH ratio >1.7, and LTE 4 ratio >1.87) in patients with POA for MCA when a tryptase level is inconclusive during POA evaluations., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Perioperative anaphylaxis is rare but is associated with significant morbidity. This complication has been well described in France by the GERAP (Groupe d'Etude des Réactions Anaphylactiques Périopératoires), a network focused on its study. The epidemiology of perioperative anaphylaxis is evolving, influenced by environmental factors and clinical practice. The aim of this study was to update the epidemiology of perioperative anaphylaxis in France., Methods: This multicentre retrospective study was performed in 26 allergy clinics of the GERAP network in 2017-8., Results: There were 765 patients with perioperative anaphylaxis included. Most cases were severe, with 428 (56%) reactions graded as 3 or 4 according to the Ring and Messmer classification. Skin test results were available for 676 patients, with a culprit agent identified in 471 cases (70%). Neuromuscular blocking agents were the main cause of perioperative anaphylaxis (n=281; 60%), followed by antibiotics (n=118; 25%) and patent blue dye (n=11; 2%). Cefazolin was the main antibiotic responsible for perioperative anaphylaxis (52% of antibiotic-related reactions). Suxamethonium and rocuronium were the main neuromuscular blocking agents responsible for perioperative anaphylaxis with 7.1 (6.1-8.4) and 5.6 (4.2-7.4) reactions per 100,000 vials sold, respectively, whereas cefazolin-related cases were estimated at 0.7 (0.5-0.9) reactions per 100,000 vials sold., Conclusions: Our results confirm that most commonly identified triggering agents remain neuromuscular blocking agents. Reactions to antibiotics, particularly cefazolin, are becoming increasingly frequent. The origin of sensitisation to cefazolin is unknown, as no cross-sensitisation has been described, and it should be the subject of further study. Perioperative anaphylaxis should be followed over the years and understood given the changing triggers., Clinical Trial Registration: ClinicalTrials.gov (NCT04654923)., (Copyright © 2024 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Study Objective: We conducted this meta-analysis to summarize the available evidence and evaluate the relationship between a history of allergies/allergic diseases and perioperative anaphylaxis to offer preventive decision support., Design: Systematic review and meta-analysis of observational studies., Setting: We searched the MEDLINE (OVID), EMBASE, and the Cochrane Central Register of Controlled Trials databases for observational studies. Two investigators independently performed the search, screened the articles, and collected the study details., Measurements: Several databases were systematically searched to evaluate the relationship between a history of allergies/allergic diseases and perioperative anaphylaxis using subgroup analysis, sensitivity analysis and meta-regression., Main Results: A total of 19 studies involving 672 anaphylaxis episodes, 5608 immune-mediated reactions, and 1126 severe episodes met the eligibility criteria and were included in this meta-analysis. Drug allergies, food allergies, a history of allergies, and atopy increased the incidence of perioperative anaphylaxis (Drug allergies, odds ratio [OR] 3.54, 95% confidence interval [CI] 1.07-11.69; Food allergies, OR 2.29, 95% CI 1.23-4.26; A history of allergies, OR 4.86, 95% CI 3.65-6.49; Atopy, OR 3.58, 95% CI 1.47-8.71), but not the presence of immune-mediated reactions and the severity of perioperative anaphylaxis., Conclusions: Patients with previous drug allergies, food allergies, a history of allergies, or atopy are more likely to develop anaphylaxis during the perioperative period. Additional studies should be carried out to determine whether a history of allergies/allergic diseases is a major factor for perioperative anaphylaxis when confounders are controlled., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Study Objective: To compare the occurrence of cefazolin perioperative anaphylaxis (POA) in patients with and without a penicillin allergy label (PAL) to determine whether the prevalence of cefazolin POA differs based on the presence of a PAL., Design: Cross-sectional study., Setting: A large U.S. healthcare system in the Baltimore-D.C. region, July 2017 to July 2020., Patients: 112,817 surgical encounters across inpatient and outpatient settings in various specialties, involving 90,089 patients. Of these, 4876 (4.3%) encounters had a PAL., Interventions: Perioperative cefazolin administration within 4 h before surgery to 4 h after the procedure began., Measurements: The primary outcome was cefazolin POA in patients with and without PALs. Potential POA cases were identified based on tryptase orders or diphenhydramine administrations within the initial cefazolin administration to 6 h postoperatively. Verification included two validation steps. The first checked for hypersensitivity reaction (HSR) documentation, and the second, led by Allergy specialists, identified POA and the probable culprit. The secondary outcome looked at cefazolin use trends in patients with a PAL, stratified by setting and specialty., Main Results: Of 112,817 encounters, 1421 (1.3%) had possible cefazolin HSRs. Of these, 22 (1.5%) had POA, resulting in a 0.02% prevalence. Of these, 13 (59.1%) were linked to cefazolin and 9 (40.9%) attributed to other drugs. Only one cefazolin POA case had a PAL, indicating no significant difference in cefazolin POA prevalence between patients with and without PALs (p = 0.437). Perioperative cefazolin use in patients with PALs steadily increased from 2.6% to 6.0% between 2017 and 2020, specifically in academic settings., Conclusions: The prevalence of cefazolin POA does not exhibit significant differences between patients with and without PALs, and notably, the incidence remains remarkably low. Based on these findings, it is advisable to view cefazolin as an acceptable choice for prophylaxis in patients carrying a PAL., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: While safety of influenza vaccines is well-established, some studies have suggested potential associations between influenza vaccines and certain adverse events (AEs). This study examined the safety of the 2022-2023 influenza vaccines among U.S. adults ≥ 65 years., Methods: A self-controlled case series compared incidence rates of anaphylaxis, encephalitis/encephalomyelitis, Guillain-Barré Syndrome (GBS), and transverse myelitis following 2022-2023 seasonal influenza vaccinations (i.e., any, high-dose or adjuvanted) in risk and control intervals among Medicare beneficiaries ≥ 65 years. We used conditional Poisson regression to estimate incidence rate ratios (IRRs) and 95 % confidence intervals (CIs) adjusted for event-dependent observation time and seasonality. Analyses also accounted for uncertainty from outcome misclassification where feasible. For AEs with any statistically significant associations, we stratified results by concomitant vaccination status., Results: Among 12.7 million vaccine recipients, we observed 76 anaphylaxis, 276 encephalitis/encephalomyelitis, 134 GBS and 75 transverse myelitis cases. Only rates of anaphylaxis were elevated in risk compared to control intervals. With all adjustments, an elevated, but non-statistically significant, anaphylaxis rate was observed following any (IRR: 2.40, 95% CI: 0.96-6.03), high-dose (IRR: 2.31, 95% CI: 0.67-7.91), and adjuvanted (IRR: 3.28, 95% CI: 0.71-15.08) influenza vaccination; anaphylaxis IRRs were 2.54 (95% CI: 0.49-13.05) and 1.64 (95% CI: 0.38-7.05) for persons with and without concomitant vaccination, respectively., Conclusions: Rates of encephalitis/encephalomyelitis, GBS, or transverse myelitis were not elevated following 2022-2023 seasonal influenza vaccinations among U.S. adults ≥ 65 years. There was an increased rate of anaphylaxis following influenza vaccination that may have been influenced by concomitant vaccination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

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., (© 2024 The Authors. Anaesthesia published by John Wiley & Sons Ltd on behalf of Association of Anaesthetists.)

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.

Background: The epidemiology and management of anaphylaxis are not well-reported in Asia., Methods: A regional pediatric anaphylaxis registry was established by the Asia-Pacific Research Network for Anaphylaxis (APRA), using standardized protocols for prospective data collection, to evaluate the triggers and management of anaphylaxis in the Asia-Pacific region. Pediatric patients below 18 years presenting with anaphylaxis across four Asian countries/cities (Thailand, Singapore, Hong Kong (HK), and Qingdao) were included. Allergen triggers, symptoms, anaphylaxis severity, and management were compared., Results: Between 2019 and 2022, 721 anaphylaxis episodes in 689 patients from 16 centers were identified. The mean age at anaphylaxis presentation was 7.0 years (SD = 5.2) and 60% were male. Food was the most common trigger (62%), particularly eggs and cow's milk in children aged 3 years and below. In school-age children, nut anaphylaxis was most common in HK and Singapore, but was rare in the other countries, and wheat was the top allergen in Bangkok. Shellfish anaphylaxis was most common in children aged 7-17. Adrenaline was administered in 60% of cases, with 9% given adrenaline before hospital arrival. Adrenaline devices were prescribed in up to 82% of cases in Thailand but none in Qingdao., Conclusions: The APRA identified food as the main trigger of anaphylaxis in children, but causative allergens differed even across Asian countries. Fewer than two-thirds of cases received adrenaline treatment, pre-hospital adrenaline usage was low, and adrenaline device prescription remained suboptimal. The registry recognizes an unmet need to strengthen anaphylaxis care and research in Asia-Pacific., (© 2024 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: Cow's milk is one of the most common and burdensome allergens in pediatrics, and it can induce severe anaphylactic reactions in children. However, data on cow's milk-induced anaphylaxis are sparse., Objective: To describe the epidemiology of pediatric cow's milk-induced anaphylaxis and to determine risk factors for repeat emergency department (ED) epinephrine administration., Methods: Between April 2011 and May 2023, data were collected on children with anaphylaxis presenting to 10 Canadian EDs. A standardized form documenting symptoms, triggers, treatment, and outcome was used. Multivariate logistic regression was used., Results: Of 3118 anaphylactic reactions, 319 milk-induced anaphylaxis cases were identified (10%). In the prehospital setting, 54% of patients with milk-induced anaphylaxis received intramuscular epinephrine. In those with milk-induced anaphylaxis, receiving epinephrine before presenting to the ED was associated with a reduced risk of requiring 2 or more epinephrine doses in the ED (adjusted odds ratio, 0.95 [95% CI, 0.90-0.99]). Children younger than 5 years of age were more likely to experience a mild reaction compared with that in older children, who experienced a moderate reaction more often (P < .0001). Compared with other forms of food-induced anaphylaxis, children presenting with milk-induced anaphylaxis were younger; a greater proportion experienced wheezing and vomiting, and less experienced angioedema., Conclusion: Prehospital epinephrine in pediatric milk-induced anaphylaxis is underused; however, it may decrease risk of requiring 2 ED epinephrine doses. Milk-induced anaphylaxis in children younger than 5 years of age may be less severe than in older children. Wheezing and vomiting are more prevalent in milk-induced anaphylaxis compared with that of other foods., Competing Interests: Disclosures The authors have no conflicts of interest to report., (Copyright © 2023 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

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., (© 2024. The Author(s).)

Background: During coronavirus disease 2019 (COVID-19) pandemic, several COVID-19 vaccines were licensed with fast-track procedures. Although these vaccines have demonstrated high immunogenicity, there has been concerns on the serious adverse events (AEs) following COVID-19 vaccination among adolescents. We aimed to analyze comparative safety of COVID-19 vaccination in adolescents., Methods: In this pharmacovigilance study, we performed a disproportionality analysis using VigiBase, the World Health Organization's global individual case safety report (ICSR) database. To compare serious AEs reported following COVID-19 vaccines vs. all other vaccines in adolescents aged 12-17 years, ICSRs following any vaccines on adolescents aged 12-17 years were included, defining cases as reports with the AEs of interest, with all other AEs as non-cases. The AEs of interest were myocarditis/pericarditis, multisystem inflammatory syndrome/Kawasaki disease (MIS/KD), anaphylaxis, Guillain-Barré syndrome (GBS), and immune thrombocytopenia (ITP). We conducted a disproportionality analysis to estimate reporting odds ratio (ROR) with 95% confidence interval (CI) for each AE of interest, adjusted for sex by using logistic regression., Results: Of 99,735 AE reports after vaccination in adolescents, 80,018 reports were from COVID-19 vaccinated adolescents (52.9% females; 56.3% America). The AEs of interest were predominantly reported as serious AE (76.1%) with mRNA vaccines (99.4%). Generally, higher reporting odds for the AEs were identified following COVID-19 vaccination in adolescents; myocarditis/pericarditis (2,829 reports for the COVID-19 vaccine vs. 35 for all other vaccines, adjusted ROR [aROR], 19.61; 95% CI, 14.05-27.39), and MIS/KD (104 vs. 6, aROR, 4.33; 95% CI, 1.89-9.88). The reporting odds for anaphylaxis (515 vs. 165, aROR, 0.86; 95% CI, 0.72-1.02), GBS (94 vs. 40, aROR, 0.64; 95% CI, 0.44-0.92) and ITP (52 vs. 12, aROR, 1.12; 95% CI, 0.59-2.09) were not significantly higher following COVID-19 vaccination., Conclusion: In this study, there were disproportionate reporting of immune-related AEs following COVID-19 vaccination. While awaiting definitive evidence, there is a need to closely monitor for any signs of immune-related AEs following COVID-19 vaccination among adolescents., Competing Interests: The authors declare no competing interests. Dr. Shin received grants from the Ministry of Food and Drug Safety, the National Research Foundation of Korea, and Pharmaceutical Companies, including Pfizer, Celltrion, and SK bioscience. No other relationships or activities have influenced the submitted work. No other relationships or activities have influenced the submitted work., (© 2024 The Korean Academy of Medical Sciences.)

Background: Evidence suggests that children who had received an initial priming dose of whole-cell pertussis (wP) vaccine, rather than acellular pertussis (aP) vaccine, had a lower risk of developing IgE-mediated food allergy, the most common cause of anaphylaxis-related hospital presentations of childhood., Objective: To assess the association between wP versus aP vaccination in infancy and subsequent hospital presentations for anaphylaxis., Methods: This study was preregistered under PMID 34874968. Perinatal records for a cohort of New South Wales-born children (1997-1999) receiving their first dose of pertussis-containing vaccine before age 4 months were probabilistically linked to hospital and immunization records. We used adjusted Cox models to estimate hazard ratios (aHRs) and 95% CIs for anaphylaxis-coded hospitalizations., Results: There were 218,093 New South Wales-born children who received a first dose of wP or aP before age 4 months. Among these children, 86 experienced at least one hospitalization for food-induced anaphylaxis at age 5-15 years (range of events per patient, one to three). The person-time of follow-up was 1,476,969 years, and 665,519 years for children vaccinated with wP as a first dose (wP-1 children) and aP as a first dose (aP-1 children), respectively. The incidence rates for first hospitalization for food anaphylaxis were 3.5 (95% CI, 2.6-4.6) and 5.1 (95% CI, 3.5-7.1) per 100,000 child-years among wP-1 children and aP-1 children, respectively (aHR for wP vs aP = 0.47; 95% CI, 0.26-0.83). For first admission for venom anaphylaxis, the incidence rate was 4.9 (95% CI, 3.9-6.2) per 100,000 child-years among wP-1 children and 5.1 (95% CI, 3.5-7.1) per 100,000 child-years among aP-1 children (aHR for wP vs aP = 0.92; 95% CI, 0.53-1.60), and for all-cause anaphylaxis, the incidence rate was 10.6 (95% CI, 9.0-12.4) per 100,000 child-years among wP-1 children and 12.8 (95% CI, 10.2-15.8) per 100,000 child-years among aP-1 children (aHR for wP vs aP = 0.92; 95% CI, 0.53-1.60)., Conclusion: Vaccination with wP in infancy was associated with a lower risk of hospitalizations for food-induced anaphylaxis (and therefore severe IgE-mediated food allergy) occurring in childhood., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

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.

Background: A close association between hereditary alpha-tryptasemia (HAT) and mast cell (MC) disorders has been previously reported. However, the relationship between HAT and the diagnostic subtypes and clinical features of MC disorders still remains to be established., Objective: To determine the prevalence of HAT in healthy donors (HD) vs patients with different diagnostic subtypes of MC activation syndromes (MCAS) and mastocytosis, and its relationship with the clinical behavior of the disease., Methods: A total of 959 subjects were studied including 346 healthy donors (HD), 464 mastocytosis, and 149 non-clonal MCAS patients. Molecular studies to assess the TPSAB1 genotype were performed, and data on serum baseline tryptase (sBT) and basal MC-mediator release episodes and triggers of anaphylaxis were collected., Results: HAT was detected in 15/346 (4%) HD versus 43/149 (29%) non-clonal MCAS and 84/464 (18%) mastocytosis cases. Among mastocytosis, HAT was more frequently found in patients with MC-restricted KIT D816V (21% vs. 10% among multilineage KIT D816V patients; p = .008). Overall, median sBT was higher in cases presenting with HAT (28.9 vs. 24.5 ng/mL; p = .008), while no significant differences in sBT were observed among HAT + mastocytosis patients depending on the presence of 1 vs. ≥2 extra copies of the α-tryptase gene (44.1 vs. 35.2 ng/mL, p > .05). In turn, anaphylaxis was more frequently observed in HAT + versus HAT - mastocytosis patients (76% vs. 65%; p = .018), while HAT + and HAT - patients who did not refer anaphylaxis as the presenting symptom (n = 308) showed a similar prevalence of subsequent anaphylaxis (35% vs. 36%, respectively)., Conclusion: The frequency of HAT in MC disorders varies according to the diagnostic subtype of the disease. HAT does not imply a higher risk (and severity) of anaphylaxis in mastocytosis patients in whom anaphylaxis is not part of the presenting symptoms of the disease., (© 2023 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: The incidence of anaphylaxis after receipt of yellow fever (YF) vaccine is highly variable based upon previously published reports. Anaphylaxis after receiving the YF vaccine has been reported to range from 0 up to 22 per 1 000 000 doses. Our clinical experience suggested increased incidence, which prompted our investigation. We sought to evaluate the current incidence rate of anaphylaxis after receipt of the 17D-204 strain YF-VAX® brand reported in the US., Methods: We performed a retrospective review of the Vaccine Adverse Event Reporting System (VAERS) reports of anaphylaxis after receiving the YF-VAX vaccine occurring between 1 October 1999 and 30 September 2018. We utilized the Brighton Collaboration Case Definition and inclusion determination was made by a board-certified allergist. We also obtained the total number of YF-VAX doses distributed across the US during this same time-period and then calculated an updated incidence rate of YF-VAX vaccine-associated anaphylaxis., Results: We identified 132 potential cases of possible or probable anaphylaxis. Of these, 111 met inclusion criteria: level 1 (n = 51), level 2 (n = 59) and level 3 (n = 1). The manufacturer reported a total distribution of 7 624 160 doses of YF-VAX from 1 October 1999 to 30 September 2018. The calculated incidence rate of YF-VAX vaccine-associated anaphylaxis is estimated at 14.6 events per 1 000 000 doses., Conclusions: We conclude the estimated rate of anaphylaxis per VAERS reports is 14.6 events per 1 000 000 doses after YF-VAX vaccination. This is consistent with some previous reports and substantially higher than rates of anaphylaxis after other vaccines., (Published by Oxford University Press on behalf of International Society of Travel Medicine 2023.)

Objectives: Evidence-based guidelines have been created and disseminated by multiple organizations to standardize the care of pediatric patients with anaphylaxis. Differences across these guidelines can cause confusion and potentially errors in clinical practice leading to patient harm. The aim of this study was to describe and identify patterns of variation in the current guidelines., Methods: A narrative review with 3 major components was designed. First, a narrative review of current, peer-reviewed, guidelines published by national and international allergy and immunology, pediatric, and emergency medicine organizations was performed. That was followed by a gray literature review of guidelines by resuscitation councils and national health organizations. The third component focused on the translation of these guidelines at local and institutional levels by reviewing clinical pathways published by academic institutions., Results: With regard to the fixed epinephrine autoinjector dosing, 50% (6 of 12) of the reviewed guidelines offered weight-based and 41.7% (5 of 12) age-based dosing recommendations. Furthermore, different weight cutoffs for the 0.15- and 0.3-mg autoinjectors were identified among guidelines. Variation was identified in the description of intramuscular epinephrine concentration ("1:1000," "1 mg/mL," or both), the recommended concentration for intravenous administration ("1:10,000" or "1:1000"), or the rate of infusion or titration. Eight of the 12 guidelines (66.7%) recommend a dose in milligrams, and 33.3% (4 of 12) in micrograms. Five of 12 (41.7%) used both milliliters and milligrams or micrograms., Conclusions: Notable variation in the current guidelines for the acute management of anaphylaxis in the pediatric population was identified. Flagging this variability could help inform a consensus-based approach toward harmonization of guidelines, which in turn could streamline the management of anaphylaxis in pediatric patients across the United States, Canada, Ireland, the United Kingdom, Europe, Australia, and New Zealand, and hopefully prevent errors and mitigate patient harm., Competing Interests: Disclosure: The authors declare no conflict of interest and no funding sources., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: There are few studies of perioperative hypersensitivity reactions in children. The diagnosis of perioperative hypersensitivity reactions may be under estimated because it is difficult to recognize the reactions. Anaphylaxis may go unnoticed because of patient unconsciousness. Urticaria may be missed due to sterile drapes. The aim of this study was to prospectively evaluate perioperative hypersensitivity reactions., Methods: In this prospective study, patients with suspected perioperative hypersensitivity reactions aged 0-18 years who underwent surgery at the Department of Pediatric Surgery, Cerrahpasa Faculty of Medicine, between 2019 and 2021 were investigated. Suspected reactions in the perioperative period were graded according to the Ring and Messmer scale. Patients with suspected reactions were examined 4-6 weeks after the reaction. If necessary, specific IgE and basophil activation tests were performed. Reactions of grades III-IV were considered anaphylaxis. If one test modality was strongly positive and there was a relevant time point or repeated allergic reactions, or at least two test modalities were positive, hypersensitivity was confirmed. In all patients, serum tryptase levels were analyzed at the time of the reaction, 2 h after the reaction, and 4-6 weeks after the reaction as part of the allergic evaluation., Results: A total of 29 patients (8 female, 21 male) suspected of having an intraoperative reaction during the study were included in the analysis. Perioperative hypersensitivity reactions were noted in 1 patient. The incidence of perioperative hypersensitivity reactions was reported to be 0.03% (n = 1/2861). While anaphylaxis was confirmed in 1 patient, 5 patients were considered possible anaphylaxis cases., Conclusion: Perioperative hypersensitivity reactions can be life-threatening and may recur with further administration. Collaboration between pediatric surgeons, anesthesiologists, and allergists can prevent further reactions. All suspected cases should be evaluated by an experienced allergist soon after the initial reaction., (© 2023 Acta Anaesthesiologica Scandinavica Foundation.)

Background: To properly assess an association between vaccines and specific adverse events requires a comparison between the observed and background rates; however, studies in South Korea are currently limited. Therefore, in this study, we estimated the background incidence of anaphylaxis, myocarditis, pericarditis, Guillain-Barré syndrome (GBS), and mortality in South Korea., Methods: A retrospective cohort study was conducted using the National Sample Cohort (NSC) data. Using NSC, the background incidence rate was estimated by dividing the number of episodes during 2009-2019 by the total population by year and then multiplying by 100,000. Using Statistics Korea data, the background mortality rate was estimated by dividing the number of deaths, during 2009-2019 by the standard population for that year and then multiplying by 100,000. Using background mortality rates, we predicted mortality rates for 2021 using autoregressive integrated moving average models. Further, the expected mortality rates were compared with observed mortality rates., Results: The age-adjusted incidence rate (AIR) of anaphylaxis increased from 4.28 to 22.90 cases per 100,000 population (p = 0.003); myocarditis showed no significant increase, changing from 0.56 to 1.26 cases per 100,000 population (p = 0.276); pericarditis increased from 0.94 to 1.88 cases per 100,000 population (p = 0.005); and GBS increased from 0.78 to 1.21 cases per 100,000 population (p = 0.013). The age-adjusted mortality rate decreased from 645.24 to 475.70 deaths per 100,000 population (p <0.001). The 2021 observed/expected mortality rates for overall (ratio: 1.08, 95% confidence interval [CI]: 1.07-1.08), men (ratio: 1.07, 95% CI: 1.07-1.08), and women (ratio: 1.08, 95% CI: 1.07-1.09), were all significantly higher. When stratified by age group, those aged ≥80 (ratio: 1.16, 95% CI: 1.15-1.17), 60-69 (ratio: 1.11, 95% CI: 1.10-1.13), and 20-29 years old (ratio: 1.07, 95% CI: 1.02-1.13) were also significantly higher., Conclusion: Through the estimation of background rates related to anaphylaxis, myocarditis, pericarditis, GBS, and mortality, we established a reference point for evaluating the potential excess occurrence of adverse events following COVID-19 vaccination. This reference point serves as substantive evidence supporting the safety profile of COVID-19 vaccines., Competing Interests: All authors declare that they have no conflict of interest., (Copyright: © 2024 Jeong, Chun. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: Following the withdrawal of propacetamol in Europe owing to safety issues, the regulatory authority of South Korea requested a post-marketing surveillance study to investigate its safety profile., Materials and Methods: We conducted nested case-control and case-time-control (CTC) analyses of cases and controls identified for outcomes of interest, including anaphylaxis, thrombosis, and Stevens-Johnson syndrome (SJS), using the claims database of South Korea, 2010-2019. Risk-set sampling was used to match each case with up to 10 controls for age, sex, cohort entry date, and follow-up duration. Exposure to anaphylaxis, thrombosis, and SJS was assessed within 7, 90, and 30 days of the index date, respectively. We calculated odds ratios (OR) with 95% confidence intervals (CIs) using conditional logistic regression to assess the risk of outcomes associated with propacetamol., Results: We identified cases of anaphylaxis (n=61), thrombosis (n=95), and SJS (n=1) and matched them to controls (173, 268, and 4, respectively). In the nested case-control analysis, the ORs for anaphylaxis and SJS were inestimable given the small number of propacetamol users during the risk period; meanwhile, the OR for thrombosis was 1.60 (95% CI 0.71-3.62). In the CTC design, the effect estimate was only estimated for thrombosis (OR 0.56, 95% CI 0.09-3.47)., Conclusion: In both nested case-control and CTC analyses, propacetamol was not associated with an increased risk of anaphylaxis, thrombosis, or SJS. The findings from this study, which used routinely collected clinical data, provide reassuring real-world evidence regarding the safety of propacetamol in a nationwide population to support regulatory decision-making., Competing Interests: Dr. Shin received grants from the Ministry of Food and Drug Safety, the National Research Foundation of Korea, and pharmaceutical companies, including Yungjin Pharm, Pfizer, Celltrion, and SK Bioscience. No other relationships or activities have influenced the submitted work. The other authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2024.)

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., (© 2023 Royal Australasian College of Physicians.)

Background: Undertreatment of anaphylaxis with epinephrine continues to be an unmet need and is a particular challenge among infants and toddlers., Objective: To address this gap by identifying barriers and solutions to appropriate and timely administration of epinephrine., Methods: We conducted a national online survey among primary caregivers of children who experienced a severe food-induced allergic reaction when younger than 36 months. Outcomes of interest included epinephrine use in community and health care settings to treat probable anaphylaxis., Results: Of 264 probable anaphylaxis cases, 39% of infants (aged <12 months) and 61% of toddlers (aged 12-35 months) received epinephrine at any time during the child's most severe allergic reaction (P = .001). A previous diagnosis of a food allergy was reported in 62% of cases where epinephrine was used compared with 26% of cases where epinephrine was not used (P < .001). In children with a previous diagnosis of a food allergy, epinephrine was used in 89% of those who were prescribed an anaphylaxis action plan compared with 50% of those without a plan (P = .001). The adjusted odds ratio for the association between having an anaphylaxis action plan and epinephrine use in cases of probable anaphylaxis was 5.39 (95% confidence interval, 2.18-13.30)., Conclusions: Epinephrine use at any time (including in health care settings) during probable anaphylaxis is more likely in infants and toddlers with a previously diagnosed food allergy than those without diagnosis. The provision of an anaphylaxis action plan is also associated with increased epinephrine use during probable anaphylaxis in this population., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)