Clinical characteristics and management of pediatric egg-induced anaphylaxis: A cross-sectional study.

BACKGROUND: Egg is the third most common food allergy in children; however, data on pediatric egg-induced anaphylaxis are sparse. OBJECTIVE: To describe the clinical characteristics, management, and outcomes of pediatric egg-induced anaphylaxis. METHODS: Children presenting with anaphylaxis were recruited from 13 emergency departments as part of the Cross-Canada Anaphylaxis Registry, from which data on anaphylaxis triggered by egg were extracted. Multivariate logistic regression was used to determine factors associated with prehospital epinephrine autoinjector (EAI) use and to compare anaphylaxis triggered by egg with other triggers of food-induced anaphylaxis (FIA). RESULTS: We recruited 302 children with egg-induced anaphylaxis. The mean age was 2.6 years (SD = 3.6), and 55.3% were male. Only 39.4% had previously been diagnosed with an egg allergy. Prehospital EAI use was 32.1%, but this was not significantly lower than in other triggers of FIA (P = .26). Only 1.4% of patients required hospital admission. Relative to other triggers of FIA, patients with egg-induced anaphylaxis were significantly younger (P < .001) and exhibited more vomiting (P = .0053) and less throat tightness (P = .0015) and angioedema (P < .001). CONCLUSION: To the best of our knowledge, this is the largest published cohort of pediatric egg-induced anaphylaxis. In this cohort, prehospital EAI use was very low. In addition, we identified certain symptoms that distinguish egg-induced from other triggers of FIA. Taken together, high suspicion is crucial in identifying egg-induced anaphylaxis, given the younger patient demographic and frequent lack of FIA history.

Exploring Perceptions of Biologic Therapies: A Qualitative Study Among Canadians Living with Severe Asthma.

INTRODUCTION: Biologic therapies have demonstrated benefits for individuals with severe asthma, including reduced daily symptoms and severe exacerbations. However, data describing patient perspectives on these treatments are limited. This study sought to understand the preferences and priorities of Canadians with severe asthma in the context of novel biologic treatment options. METHODS: Semi-structured, qualitative interviews were conducted among Canadians with severe asthma from July to August 2022. Purposeful sampling included individuals with and without biologic therapy experience. All participants described daily life with severe asthma, experiences and priorities related to asthma treatment and their impressions of biologics. Reflexive thematic analysis was used to explore patterns in the data. RESULTS: Among 18 individuals included, 10 were currently taking or had prior experience with biologic treatment for asthma. Those who had never been treated with biologics were unfamiliar with them, considering treatment, or believed that they may not be eligible. Four themes were developed to convey the perspectives of participants on biologics: (1) life-changing benefits, but not for all; (2) navigating barriers to being prescribed and remaining adherent to biologic treatments; (3) treatment administration preferences are not only about convenience; (4) concerns about safety and the unknown as a source of treatment hesitancy. CONCLUSIONS: Findings suggest that the clinical benefits of biologics align with patient perceptions of achieving good asthma control. However, treatment gaps persist among individuals who do not experience a meaningful improvement in their asthma symptoms and those who face barriers accessing biologics. People with severe asthma attributed importance to greater availability of at-home treatment options, improved access to financial support to cover treatment costs and support to address safety concerns. This research provides insight into patient-based treatment priorities and preferences for biologics, which may help inform decision-making related to emerging therapies for severe asthma.

For people with severe asthma, biologics are a treatment option that can be taken in addition to their regular medication. In this study, we asked 18 Canadians with severe asthma about how having severe asthma affects their lives, their current and previous asthma treatments, and their views on biologics. Ten people in this study were currently taking or had previously taken biologics for severe asthma. We found that biologics can be life changing. Also, people with severe asthma can find it difficult to get on and stay on biologics. They would like financial and educational support when considering biologics and prefer to take biologics at home, if possible. This study helps us understand the priorities and preferences related to biologics of patients with severe asthma.

Milk-induced anaphylaxis among children presenting to Canadian emergency departments.

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.

Assessing Pediatric Cephalosporin Allergic Reactions Through Direct Graded Oral Challenges.

BACKGROUND: Cephalosporins, ß-lactam antibiotics, commonly cause allergic reactions. OBJECTIVE: To assess the clinical characteristics and management of pediatric patients with suspected cephalosporin allergy using direct graded oral challenges (GOCs). METHODS: Children referred for suspected cephalosporin allergy at 4 Canadian clinics were recruited over 10 years. Data on demographics, clinical reaction characteristics, and management were collected through a questionnaire. Patients underwent a direct GOC (initially 10% of the treatment dose, then 90% after 20 min), and reactions were monitored 1 week postchallenge. Families were contacted annually for up to 5 years to detect subsequent antibiotic reactions. Logistic regression analysis identified factors associated with positive GOC reactions. RESULTS: Among the 136 patients reporting cephalosporin allergy, 75 (55.1%) were males with a median age of 3.9 years (interquartile range 2.3-8.7). Cefprozil represented the most common cephalosporin linked to the index reaction (67.6% of cases). Of the 136 direct GOCs, 5.1% had an immediate and 4.4% a nonimmediate reaction, respectively. Positive GOCs conducted in children with a history of skin-limited nonsevere rashes were classified as mild, benign skin rashes. Positive GOCs were more likely in children with food allergies (adjusted odds ratio 1.14; 95% confidence interval [95% CI] 1.00-1.29). CONCLUSIONS: Direct GOCs are safe and effective for diagnosing pediatric cases that report nonvesicular skin-limited symptoms while being treated with cephalosporins.

Managing anaphylaxis: Epinephrine, antihistamines, and corticosteroids: More than 10 years of Cross-Canada Anaphylaxis REgistry data.

BACKGROUND: Epinephrine is the first-line treatment for anaphylaxis but is often replaced with antihistamines or corticosteroids. Delayed epinephrine administration is a risk factor for fatal anaphylaxis. Convincing data on the role of antihistamines and corticosteroids in anaphylaxis management are sparse. OBJECTIVE: To establish the impact of prehospital treatment with epinephrine, antihistamines, and/or corticosteroids on anaphylaxis management. METHODS: Patients presenting with anaphylaxis were recruited prospectively and retrospectively in 10 Canadian and 1 Israeli emergency departments (EDs) between April 2011 and August 2022, as part of the Cross-Canada Anaphylaxis REgistry. Data on anaphylaxis cases were collected using a standardized form. Primary outcomes were uncontrolled reactions (>2 doses of epinephrine in ED), no prehospital epinephrine use, use of intravenous fluids in ED, and hospital admission. Multivariate regression was used to identify factors associated with primary outcomes. RESULTS: Among 5364 reactions recorded, median age was 8.8 years (IQR, 3.78-16.9); 54.9% of the patients were males, and 52.5% had a known food allergy. In the prehospital setting, 37.9% received epinephrine; 44.3% received antihistamines, and 3.15% received corticosteroids. Uncontrolled reactions happened in 250 reactions. Patients treated with prehospital epinephrine were less likely to have uncontrolled reactions (adjusted odds ratio [aOR], 0.955 [95% CI, 0.943-0.967]), receive intravenous fluids in ED (aOR, 0.976 [95% CI, 0.959-0.992]), and to be admitted after the reaction (aOR, 0.964 [95% CI, 0.949-0.980]). Patients treated with prehospital antihistamines were less likely to have uncontrolled reactions (aOR, 0.978 [95% CI, 0.967-0.989]) and to be admitted after the reaction (aOR, 0.963 [95% CI, 0.949-0.977]). Patients who received prehospital corticosteroids were more likely to require intravenous fluids in ED (aOR, 1.059 [95% CI, 1.013-1.107]) and be admitted (aOR, 1.232 [95% CI, 1.181-1.286]). CONCLUSION: Our findings in this predominantly pediatric population support the early use of epinephrine and suggest a beneficial effect of antihistamines. Corticosteroid use in anaphylaxis should be revisited.

Results of a mixed-methods study on barriers to physician recruitment in Newfoundland and Labrador.

Background: Like many rural and remote parts of Canada, the province of Newfoundland and Labrador (NL) struggles to maintain a skilled healthcare workforce. As many as 20% of people in the province are thought to be without a primary care physician. The purpose of this study was to determine the barriers recent Memorial University of Newfoundland medical alumni have faced in establishing medical practice in NL. Methods: An online survey followed by question-standardised focus group sessions. Results: Two hundred and ninety-one physicians who graduated from Memorial University of Newfoundland medical school between the years of 2003 and 2018 completed the survey. Nearly 80% of respondents recalled that NL was their preferred practice location at some point during training: 79.4% (n = 231) at the beginning of medical school and 77.7% (n = 226) at the beginning of residency training. However, at the time of the survey, only 160 (55.0%) respondents were working in NL. Respondents reported significant cultural and systemic barriers in trying to work in NL, including ineffective recruitment offices, lack of transparency in communication with health authorities, inequitable distribution of resources and workloads, lack of appropriate resources to support new positions, and return-of-service agreements that are not honoured or followed-up. Conclusion: Our study outlines a number of ways in which recruitment and retention could be improved, ultimately improving provincial health care and helping to fulfil the mandate of the medical school.

Résumé Contexte: Comme de nombreuses régions rurales et isolées du Canada, la province de Terre-Neuve-et-Labrador (T.-N.-L.) a du mal à maintenir une main-d'œuvre qualifiée dans le domaine de la santé. On estime que 20% des habitants de la province n'ont pas de médecin de premier recours. L'objectif de cette étude était de déterminer les obstacles auxquels les anciens étudiants en médecine de l'Université Memorial de Terre-Neuve ont été confrontés lors de l'établissement d'une pratique médicale à Terre-Neuve-et-Labrador. Méthodes: Une enquête en ligne suivie de sessions de groupes de discussion normalisées par des questions. Résultats: 291 médecins diplômés de l'école de médecine de MUN entre 2003 et 2018 ont répondu à l'enquête. Près de 80% des répondants SE sont souvenus que Terre-Neuve était leur lieu d'exercice préféré à un moment donné de leur formation: 79,4% (n = 231) au début de leurs études de médecine et 77,7% (n = 226) au début de leur formation en résidence. Cependant, au moment de l'enquête, seuls 160 (55,0%) répondants travaillaient à T.-N.-L. Les répondants ont fait état d'obstacles culturels et systémiques importants lorsqu'ils ont tenté de travailler à T.-N.-L., notamment l'inefficacité des bureaux de recrutement, le manque de transparence dans la communication avec les autorités sanitaires, la répartition inéquitable des ressources et des charges de travail, le manque de ressources appropriées pour soutenir les nouveaux postes, et les accords de retour de service qui ne sont pas respectés ou qui ne font pas l'objet d'un suivi. Conclusion: Notre étude présente un certain nombre de moyens d'améliorer le recrutement et la fidélisation, ce qui permettrait en fin de compte d'améliorer les soins de santé provinciaux et d'aider à remplir le mandat de la faculté de médecine. Mots-clés: Médecin, recrutement, rétention, éducation médicale, Canada, Terre-Neuve-et-Labrador, rural, éloigné.

Temporal trends in anaphylaxis ED visits over the last decade and the effect of COVID-19 pandemic on these trends.

BACKGROUND: Anaphylaxis is an acute systemic and potentially fatal allergic reaction. We evaluated trends in yearly rates of anaphylaxis in a pediatric Emergency Department (ED) in Montreal, Canada. METHODS: A prospective and retrospective recruitment process was used to find families of children who had presented with anaphylaxis at the Montreal Children's Hospital between April 2011 and April 2021. Using a uniform recruitment form, data were collected. Anaphylaxis patterns were compared to clinical triggers using descriptive analysis. RESULTS: Among 830,382 ED visits during the study period, 2726 (26% recruited prospectively) presented with anaphylaxis. The median age was 6 years (IQR: 0.2, 12.00), and 58.7% were males. The relative frequency of anaphylaxis cases doubled between 2011-2015, from 0.22% (95% CI, 0.19, 0.26) to 0.42 March 2020, the total absolute number of anaphylaxis cases and relative frequency declined by 24 cases per month (p < 0.05) and by 0.5% of ED visits (p < 0.05). CONCLUSIONS: The rate of anaphylaxis has changed over the years, representing modifications in food introduction strategies or lifestyle changes. The decrease in the frequency of anaphylaxis presenting to the ED during the COVID pandemic may reflect decreased accidental exposures with reduced social gatherings, closed school, and reluctance to present to ED.

Impact of Reaction Setting on the Management, Severity, and Outcome of Pediatric Food-Induced Anaphylaxis: A Cross-Sectional Study.

BACKGROUND: Prompt epinephrine autoinjector (EAI) use is the primary treatment for anaphylaxis. However, limited Canadian data exist on the impact of reaction location on EAI use for food-induced anaphylaxis (FIA). OBJECTIVE: We sought to investigate the setting, management, and severity of pediatric FIA. METHODS: We recruited children presenting with FIA from 11 Canadian emergency departments. Patient demographics and the setting, management, and symptoms of FIA were collected by standardized questionnaire. Factors associated with prehospital EAI use and reaction severity were determined by logistic regression. RESULTS: We recruited 3,604 children; 60.2% were male and the median age was 5.0 years (interquartile range 1.8-11.0). Among cases with a known location of FIA (85.0%), home was the most common setting (68.1%), followed by school/daycare (12.8%), other locations (11.4%; eg, park, car), and restaurants (7.4%). In the prehospital setting, EAI was administered in 36.7% of reactions at home, 66.7% in school/daycare, 40.2% in other locations, and 44.5% in restaurants. Relative to reactions occurring at school/daycare, prehospital EAI use was less likely at home (adjusted odds ratio [aOR] 0.80; 95% CI 0.76-0.84), in restaurants (aOR 0.81; 95% CI 0.75-0.87), and in other settings (aOR 0.77; 95% CI 0.73-0.83), when data were adjusted for reaction severity, sex, age, comorbidities, and province. The FIA setting was not associated with reaction severity or hospitalization. CONCLUSIONS: Prehospital EAI use was higher at school/daycare than in other settings, potentially owing to the presence of policies and training on FIA. Setting-specific interventions including educational programs and policies/laws mandating training and stocking an EAI may improve anaphylaxis recognition and treatment.

Tree nut-induced anaphylaxis in Canadian emergency departments: Rate, clinical characteristics, and management.

BACKGROUND: Data are sparse regarding tree nut-induced anaphylaxis (TNA). OBJECTIVE: To characterize rate, clinical characteristics, and management of TNA in children (0-17 years old) across Canada and evaluate factors associated with severe reactions and epinephrine use. METHODS: Between April 2011 and May 2020, data were collected on children presenting to 5 emergency departments in Canada. Multivariate logistic analysis was used to evaluate factors associated with severe reactions (stridor, cyanosis, circulatory collapse, or hypoxia) and epinephrine use. RESULTS: Among 3096 cases of anaphylaxis, 540 (17%) were induced by tree nut. The median age was 5.2 (interquartile range, 2.5-9.5) years and 65.4% were of male sex. Among all reactions, 7.0% were severe. The major tree nuts accounting for anaphylaxis were cashew (32.8%), hazelnut (20.0%), and walnut (11.5%). Cashew-induced anaphylaxis was more common in British Columbia (14.0% difference [95% confidence interval (CI), 1.6-27.6]) vs Ontario and Quebec, whereas pistachio-induced anaphylaxis was more common in Ontario and Quebec (6.3% difference [95% CI, 0.5-12.2]). Prehospital and emergency department intramuscular epinephrine administration was documented in only 35.2% and 52.4% of cases, respectively. Severe reactions were more likely among of male sex (adjusted odds ratio [aOR], 1.05 [95% CI, 1.01-1.10]), older children (aOR, 1.00 [95% CI, 1.00-1.01]), and in reactions triggered by macadamia (aOR, 1.27 [95% CI, 1.03-1.57]). CONCLUSION: Different TNA patterns in Canada may be because of differences in lifestyle (higher prevalence of Asian ethnicity in British Columbia vs Arabic ethnicity in Ontario and Quebec). Intramuscular epinephrine underutilization urges for epinephrine autoinjector stocking in schools and restaurants, patient education, and consistent policies across Canada.

Sesame-induced anaphylaxis in pediatric patients from the cross-Canada anaphylaxis registry.

BACKGROUND: Sesame can cause severe allergic reactions and is a priority allergen in Canada. OBJECTIVE: To assess clinical characteristics and management of pediatric sesame-induced anaphylaxis and identify factors associated with epinephrine treatment. METHODS: Between 2011 and 2021, children with sesame-induced anaphylaxis presenting to 7 emergency departments (ED) in 4 Canadian provinces and 1 regional emergency medical service were enrolled in the Cross-Canada Anaphylaxis Registry. Standardized recruitment forms provided data on symptoms, severity, triggers, and management. Multivariate logistic regression evaluated associations with epinephrine treatment pre-ED and multiple epinephrine dosages. RESULTS: Of all food-induced anaphylactic reactions (n = 3279 children), sesame accounted for 4.0% (n = 130 children), of which 61.5% were boys, and the average (SD) age was 5.0 (4.9) years. Hummus containing sesame paste triggered 58.8% of reactions. In the pre-ED setting, 32.3% received epinephrine, and it was more likely to be used in boys (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.08-1.50) and those with a known food allergy (aOR, 1.36; 95% CI, 1.11-1.68]). In the ED, 47.7% of cases received epinephrine, with older children more likely to receive multiple epinephrine doses (aOR, 1.00; 95% CI, 1.00-1.02). CONCLUSION: In Canada, hummus is the major trigger of sesame-induced anaphylaxis. Knowledge translation focused on prompt epinephrine use and product-labeling policies are required to limit sesame reactions in communities.

Seafood-induced anaphylaxis in children presenting to Canadian emergency departments: Rates, clinical presentation, and management.

BACKGROUND: There is a lack of data on seafood-induced anaphylaxis in children in Canada. OBJECTIVE: To evaluate the rate, clinical features, and management of seafood-induced anaphylaxis in children presenting to emergency departments across Canada. METHODS: Children with anaphylaxis were recruited at 6 emergency departments between 2011 and 2020 as part of the Cross-Canada Anaphylaxis REgistry. A standardized form documenting symptoms, triggers, comorbidities, and management was used to collect data. RESULTS: There were 75 fish-induced and 71 shellfish-induced cases of suspected anaphylaxis, most of which were caused by salmon and shrimp, respectively. Mucocutaneous symptoms were most common, whereas respiratory symptoms were associated with patients with fish-induced reactions who have comorbid asthma (adjusted odds ratio [aOR], 1.18; 95% confidence interval [CI], 1.02-1.36). Prehospital epinephrine was underused (<35%), whereas in-hospital epinephrine was given to less than 60% of the patients. Among those with a known fish or shellfish allergy, prehospital epinephrine use was associated with known asthma (aOR 1.39 [95% CI, 1.05-1.84] and aOR 1.25 [95% CI, 1.02-1.54], respectively). Among children who were assessed by either skin test or specific immunoglobulin E, 36 patients (76.6%) with suspected fish-induced anaphylaxis and 19 patients (51.4%) with suspected shellfish-induced anaphylaxis tested positive. CONCLUSION: Prehospital epinephrine is underused in the management of seafood-induced anaphylaxis. Among children with known seafood allergy, prehospital epinephrine use is more likely if there is a known asthma comorbidity.

Establishing Amoxicillin Allergy in Children Through Direct Graded Oral Challenge (GOC): Evaluating Risk Factors for Positive Challenges, Safety, and Risk of Cross-Reactivity to Cephalosporines.

BACKGROUND: Data on the diagnostic properties of direct oral challenges without the use of skin tests in children with suspected amoxicillin allergy are sparse. OBJECTIVE: Assess the use of direct oral challenges. METHODS: A cohort study was conducted between March 2013 and March 2020, in Montreal and Winnipeg. All children referred with reported history of benign reactions (ie, limited to the skin with no mucosal lesions and no vesicles) to amoxicillin were recruited and a 2-step graded oral challenge (GOC) was conducted. Data were collected on demographic characteristics, clinical characteristics, and comorbidities. Eligible children were followed to assess reactions to subsequent use of amoxicillin and to assess the safety of cephalexin use in children with a positive GOC. RESULTS: Among 1914 children recruited, 1811 (94.6%) tolerated the GOC, 42 (2.2%) developed mild immediate reactions, and 61 (3.2%) developed mild nonimmediate reactions. Among 265 participants who had a negative GOC and reused amoxicillin, 226 (85.3%) reported tolerance and 39 (14.7%) had mild cutaneous reactions. Chronic urticaria (adjusted odds ratio [aOR], 1.16; 95% CI, 1.09-1.23) and an index reaction occurring within 5 minutes of exposure (aOR, 1.09; 95% CI, 1.04-1.14) were associated with immediate reactions during the GOC. Symptoms lasting longer than 7 days (aOR, 1.05; 95% CI, 1.02-1.09) and parental drug hypersensitivity (aOR, 1.04; 95% CI, 1.03-1.06) were associated with nonimmediate reactions. Among those reacting to the GOC, 12.5% reacted with mild cutaneous reactions to cephalexin challenge. CONCLUSIONS: Direct GOCs are an accurate and safe confirmatory to establish true hypersensitivity among children reporting benign reactions to amoxicillin.

Fruit-Induced Anaphylaxis: Clinical Presentation and Management.

BACKGROUND: Data are sparse regarding the clinical characteristics and management of fruit-induced anaphylaxis. OBJECTIVE: To assess clinical characteristics and management of patients with fruit-induced anaphylaxis and determine factors associated with severe reactions and epinephrine use. METHODS: Over 9 years, children and adults presenting with anaphylaxis to seven emergency departments in four Canadian provinces and patients requiring emergency medical services in Outaouais, Quebec were recruited as part of the Cross-Canada Anaphylaxis Registry. A standardized form documenting symptoms, triggers, and management was collected. Multivariate logistic regression was used to identify factors associated with severe reactions and epinephrine treatment in the pre-hospital setting. RESULTS: We recruited 250 patients with fruit-induced anaphylaxis, median age 10.2 years (interquartile range, 3.6-23.4 years); 48.8% were male. The most common fruit triggers were kiwi (15.6%), banana (10.8%), and mango (9.2%). Twenty-three patients reported having eczema (9.3%). Epinephrine use was low in both the pre-hospital setting and the emergency department (28.4% and 40.8%, respectively). Severe reactions to fruit were more likely to occur in spring and among those with eczema (adjusted odds ratio [aOR] = 1.12, 95% confidence interval [CI], 1.03-1.23; and 1.17, 95% CI, 1.03-1.34, respectively). Patients with moderate and severe reactions (aOR = 1.23; 95% CI, 1.06-1.43) and those with a known food allergy (aOR = 1.38; 95% CI, 1.24-1.54) were more likely to be treated with epinephrine in the pre-hospital setting. CONCLUSIONS: Severe anaphylaxis to fruit is more frequent in spring. Cross-reactivity to pollens is a potential explanation that should be evaluated further.

Differentiating Between ß-Lactam-Induced Serum Sickness-Like Reactions and Viral Exanthem in Children Using a Graded Oral Challenge.

BACKGROUND: Serum sickness-like reactions (SSLRs) are defined by the presence of rash (primarily urticaria) and joint complaints (arthralgia/arthritis) that are believed to occur due to a non-IgE-mediated response to medications. However, similar reactions can occur due to viral infections, and it can be difficult to distinguish between the two. This may lead to unnecessary avoidance of the culprit antibiotic. OBJECTIVE: We aimed to evaluate children presenting with suspected SSLRs through a graded oral challenge (GOC). METHODS: All children referred to the Montreal Children's Hospital for potential antibiotic allergy (ß-lactam or other antibiotics) and a clinical presentation compatible with SSLR were recruited for the study between March 2013 and February 2020. A standardized survey with questions on treatment, symptoms, and associated factors was completed, and a GOC (10% and subsequently 90% of the oral antibiotic dose) was conducted. Patients with a negative GOC were contacted annually to query on subsequent antibiotic use. RESULTS: Among 75 patients presenting with suspected SSLRs, the median age was 2.0 years and 46.7% were males. Most reactions were attributed to amoxicillin. Among the 75 patients, 2.7% reacted immediately (within 1 hour) to a GOC and 4.0% had a nonimmediate reaction. Of the 43 patients successfully contacted, 20 reported subsequent culprit antibiotic use of whom 25.0% had a subsequent mild reaction (macular/papular rash). CONCLUSIONS: This is the first and largest pediatric study to assess SSLR using a GOC. Our findings suggest that using a GOC is safe and appropriate for differentiating between ß-lactam-induced SSLR and viral exanthem in this population.

Risk of peanut- and tree-nut-induced anaphylaxis during Halloween, Easter and other cultural holidays in Canadian children.

BACKGROUND: It is not established whether the risk of anaphylaxis induced by peanuts or tree nuts in children increases at specific times of the year. We aimed to evaluate the risk of peanut-and tree-nut-induced anaphylaxis during certain cultural holidays in Canadian children. METHODS: We collected data on confirmed pediatric cases of anaphylaxis presenting to emergency departments in 4 Canadian provinces as part of the Cross-Canada Anaphylaxis Registry. We assessed the mean number of cases per day and incidence rate ratio (IRR) of anaphylaxis induced by unknown nuts, peanuts and tree nuts presenting during each of 6 holidays (Halloween, Christmas, Easter, Diwali, Chinese New Year and Eid al-Adha) versus the rest of the year. We estimated IRRs and 95% confidence intervals (CIs) using Poisson regression. RESULTS: Data were collected for 1390 pediatric cases of anaphylaxis between 2011 and 2020. Their median age was 5.4 years, and 864 (62.2%) of the children were boys. During Halloween and Easter, there were higher rates of anaphylaxis to unknown nuts (IRR 1.66, 95% CI 1.13-2.43 and IRR 1.71, 95% CI 1.21-2.42, respectively) and peanuts (IRR 1.86, 95% CI 1.12-3.11 and IRR 1.57, 95% CI 0.94-2.63, respectively) compared to the rest of the year. No increased risk of peanut- or tree-nut-induced anaphylaxis was observed during Christmas, Diwali, Chinese New Year or Eid al-Adha. Anaphylaxis induced by unknown nuts, peanuts and tree nuts was more likely in children aged 6 years or older than in younger children. INTERPRETATION: We found an increased risk of anaphylaxis induced by unknown nuts and peanuts during Halloween and Easter among Canadian children. Educational tools are needed to increase awareness and vigilance in order to decrease the risk of anaphylaxis induced by peanuts and tree nuts in children during these holidays.

Correction to: The International/Canadian Hereditary Angioedema Guideline.

[This corrects the article DOI: 10.1186/s13223-019-0376-8.].