Proceedings of the Canadian Society of Allergy and Clinical Immunology Annual Scientific Meeting 2021

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Background: Patients with severe asthma may require long-term oral corticosteroids (OCS) treatment to control disease. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4/interleukin-13, key/central drivers of type 2 inflammation in multiple diseases. In VENTURE (NCT02528214), dupilumab 300mg vs placebo reduced OCS dose and exacerbations and improved lung function in patients with OCS-dependent severe asthma. TRAV-ERSE, a single-arm, open-label extension study (NCT02134028), evaluated long-term safety, tolerability, and efficacy of dupilumab. We evaluated long-term maintenance of OCS reduction and clinical efficacy in VENTURE patients enrolled in TRAVERSE. Methods: LS mean percentage change from parent study baseline (PSBL) in OCS use and percentage of patients with OCS reduction ≥50%, annualized exacerbation rate, LS mean change from PSBL in lung function (FEV 1 ), and mean change from PSBL in asthma control (ACQ-5) at TRAVERSE Week48 were evaluated in VENTURE patients receiving dupilumab (dupilumab/dupilumab) or placebo (placebo/ dupilumab) enrolled in TRAVERSE.  [1.00]) from PSBL to TRAV-ERSE Week48 in dupilumab/dupilumab and placebo/dupilumab, respectively. Conclusions: Patients with severe OCS-dependent asthma demonstrated sustained OCS dose reduction and clinical outcomes improvement during TRAVERSE. The OCS-sparing effect, exacerbation reduction, and lung function and asthma control improvements of dupilumab observed in VENTURE were maintained in TRAVERSE.

Results
Background: Severe asthma exacerbations are associated with lung function impairment. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4/ interleukin-13, key and central drivers of type 2 (T2) inflammation in multiple diseases. In phase 3 QUEST (NCT02414854), add-on dupilumab 200/300mg every 2 weeks vs placebo reduced severe exacerbations and improved pre-bronchodilator forced expiratory volume in 1 second (FEV 1 ) in patients with uncontrolled, moderateto-severe asthma. Treatment effects were greater in patients with elevated T2 biomarkers. This post hoc analysis assessed the impact of severe exacerbations on post-bronchodilator FEV 1 in QUEST patients with T2 inflammatory asthma. Methods: Change from baseline in post-bronchodilator FEV 1 was assessed in QUEST patients with T2 phenotypes (≥150 eosinophils/ µL and/or FeNO ≥ 25ppb or ≥ 300 eosinophils/µL and/or FeNO ≥ 25ppb) who did/did not experience asthma exacerbations during QUEST, and in patients after experiencing a first severe exacerbation. Results: Post-bronchodilator FEV 1 recovered faster after exacerbation in dupilumab patients. Greater benefits were observed within 6 weeks of exacerbation and were sustained over time. Patients with ≥ 300 eosinophils/µL and/or FeNO ≥ 25ppb at baseline benefited most from dupilumab after first severe exacerbation event ( Background: Epinephrine is the first line treatment for anaphylaxis. The optimal dose of epinephrine in anaphylaxis is not well studied. Anaphylaxis occurs in approximately 5% of patients receiving subcutaneous immunotherapy. The recommended dose of epinephrine for adults with anaphylaxis is 0.3 to 0.5 mg. The efficacy and safety of epinephrine 0.5 mg has never been assessed in patients reacting to subcutaneous allergen immunotherapy. Methods: We reviewed the electronic medical records of two outpatient allergy practices for patients who received 0.5 mg intramuscular epinephrine as the initial dose for treatment of anaphylaxis secondary to subcutaneous allergen immunotherapy. Data on patient demographics, vital signs, and patient outcomes were collected. Counts and percentages were computed to summarize the data. Means and 95% confidence intervals (CI) were calculated for vital signs. Results: Thirty-eight patients received an initial dose of 0.5 mg intramuscular epinephrine for allergic reactions to subcutaneous allergen immunotherapy between March 2006 to February 2020. Eleven (30%) and 2 (5%) patients required a second and third dose of epinephrine respectively. Mean systolic blood pressure after administration of epinephrine was 120 mmHg (95% CI: 112-127). Data on heart rate after administration of epinephrine was available for 35 patients. Mean heart rate was 98 beats per minute (95% CI: 88-107). Twenty-two patients (58%) had resolution of symptoms in clinic. Sixteen patients (42%) were transferred to the emergency department with ongoing symptoms. Data on time to symptom resolution was available for 21 patients-the majority (81%) had symptom resolution within 30 minutes. There were no adverse reactions or fatalities. Conclusions: Use of 0.5 mg intramuscular epinephrine to treat anaphylaxis caused by subcutaneous allergen immunotherapy is safe and effective. Further studies on optimal initial dosing of intramuscular epinephrine are needed to reduce the need for repeat doses and emergency department visits due to refractory anaphylaxis Background: Data regarding anaphylaxis treatment is often poorly understood. We aimed to assess the effect of prehospital treatment of anaphylaxis on the risk of admission to hospital ward and/or intensive care unit (ICU). Methods: From April 2011 to 2021, 4801 adults (20.5%) and children (79.5%) presenting with anaphylaxis to eleven different emergency departments (ED) across Canada and Israel were recruited as part of the Cross-Canada Anaphylaxis Registry (C-CARE). A standardized form documenting prehospital treatment was obtained and their disposition was documented. Multivariate logistic regression was used to identify associations between prehospital treatment and admission to a hospital ward and/or ICU. Results: Of the recruited patients, the median age was 8.2 years [Interquartile Range (IQR 2.9, 16.5] and 56% were males. The most common prehospital treatments provided were antihistamines (44.9%), epinephrine (35.4%), short acting inhaled beta-agonists (6.3%) and corticosteroids (3.3%). Admission to a hospital ward (4.8%) and/or ICU (0.8%) was infrequent. Admission to a hospital ward was associated with being an adult and prehospital administration of corticosteroids [adjusted Odds Ratio (aOR) 1.13 (95% CI 1.11, 1.15) and 1.22 (95% CI 1.18, 1.26), respectively], while adjusting for sex, prehospital epinephrine, antihistamines and beta-agonist. Admission to an ICU was associated with prehospital use of corticosteroids [aOR 1.04 (95% CI 1.03, 1.06)], while adjusting for sex, prehospital epinephrine, antihistamines and beta-agonist. There was a decreased likelihood of being admitted to a hospital ward if the patient was administered prehospital epinephrine or antihistamines [aOR 0.98 (95% CI 0.97-0.99) and 0.97 (95% CI 0.95-0.98), respectively], while adjusting for sex, prehospital epinephrine, antihistamines and beta-agonist Conclusions: This study showed that patients who received corticosteroid for anaphylaxis before ED arrival are at higher risk of hospitalisation while the use of epinephrine and antihistamine decrease the risk of admission. Background: A diagnosis of food allergy has substantial impacts on the health-related quality of life (HRQOL) and psychosocial well-being of children and adolescents. This scoping review aims to explore the primary literature related to HRQOL and anxiety in children and adolescents diagnosed with food allergy and provide recommendations for improvement.
Methods: Searches were conducted in MEDLINE and EMBASE from database inception to March 2021 and Reference lists of included articles were screened. Non-intervention studies that reported on quality of life and/or anxiety in food allergic individuals up to age 18 were eligible for inclusion. One reviewer screened studies against predefined inclusion criteria and independently extracted data. Data were analyzed using a qualitative thematic approach. Results: 187 articles were identified, of which 21 (11.2%) articles were included. The Food Allergy Quality of Life Questionnaire (FAQLQ) was the most widely used tool (11/21). Food allergy related anxiety was not widely reported; however, several themes related to HRQOL were identified across studies. Older age (>3 years), female sex, and increased severity of past reactions resulting in epinephrine autoinjector use and/or hospitalization were found to have a negative impact on child and adolescent HRQOL. Increased rates of bullying were not consistently reported across studies; however, bullying through exposure to the allergenic food was reported in one paper. In papers that compared child HRQOL data provided by parents to child HRQOL data provided by children, parents rated their child's HRQOL better than the children themselves. Conclusions: The recognition of mental health concerns related to decreased HRQOL should be incorporated into food allergy management. Ongoing food allergy mental health education and supports should be provided to families. Collaboration between allergists and mental health professionals is needed to provide effective treatment to children and adolescents with food allergy and develop evidence-based clinical guidelines for effective management of these challenges. Background: Shrimp allergy is one of the most frequently reported food allergies in adults. The objective of this study was to determine shrimp oral food challenge (OFC) outcomes in adults consulting in a tertiary hospital center with a reported history of IgE-mediated reaction to shrimp. Methods: A retrospective chart review was performed for adults who underwent a shrimp OFC at the CHUM allergy clinic between 2017 and 2020. Patients with a convincing history of immediate IgE-mediated reaction to shrimp were included. Patients with shrimp sensitization without a clinical history of reaction to shrimp, with a reaction to seafood other than shrimp, and with reactions non-suggestive of IgE-mediated reactions were excluded. Results: A total of 135 shrimp OFCs were completed, of which 84 had a convincing history of IgE-mediated reaction after shrimp ingestion. Symptoms reported at initial reaction involved cutaneous (62%), gastrointestinal (49%), lower respiratory (35%), cardiovascular (7%) and upper respiratory (1%) systems. Anaphylaxis criteria were present in 35% of patients with a median Brown severity grade 1 of 2. The median age (range) at initial reaction and time of OFC were 28 (3-70) and 36 (14-76) years, respectively. Seventy-seven percent (36/47) were sensitized to dust mites. Six patients (7%) had positive OFCs with a median severity grade of 2. Two patients with negative low dose OFCs underwent oral immunotherapy and subsequently reacted to shrimp at home. Eleven patients (13%) had transient isolated oral symptoms but were able to complete OFC. Median skin test size was significantly higher in the shrimp-allergic group (4.5 mm; 0-10) than in the shrimp tolerant group (0 mm; 0-11, p = 0.0444).

Conclusions:
The rate of positive OFCs to shrimp in adults with a reported history of immediate reaction to shrimp was low. These findings may suggest a favorable natural history for adult-onset shrimp allergy, which warrants further prospective studies.
Background: As of 2020, 0.3% of Canadian children are reported to have sesame allergy. Although studies suggest that oral immunotherapy (OIT) should be incorporated into clinical practice, a major limitation of all current OIT protocols is the risk of anaphylaxis. We aim to explore modified OIT protocols that will promote a safer approach to sesame desensitization, without compromising effectiveness. Methods: Children less than 12 years old with a history-based sesame allergy diagnosis and a positive sesame skin prick test were recruited at hospital and community-based allergy clinics. Upon initial visit, a dose of 5-12mg of sesame protein was introduced and guardians filled out a quality-of-life questionnaire. Patients would then continue the dose for 2-5 weeks at home, fill out a symptom diary, and return to the clinic to receive a new dose. R (v4.0.2) was used to analyze the demographics of the study population in addition to the safety of the modified OIT protocols used. Results: From January 29 to June 17, 2021, 11 children (45.5% male; median age: 1 year, 10 months) were recruited. All 11 patients (100%) had eczema, two (18.2%) had asthma, and eight (72.7%) had other food allergies (mainly peanut (n = 5; 62.5%), cashew (n = 3; 37.5%), and pistachio (n = 3; 37.5%)). OIT was performed using 3 strategies: initial doses were either sesame seeds, tahini muffin, or hummus. Children were desensitized aiming to reach 2 teaspoons of hummus or equivalent of sesame protein (50mg). To date, five patients (45.5%), after on average 3.2 visits, have reached this point. Among the 964 total intake doses of sesame, two cases of mild non-anaphylactic allergic reaction and one case of moderate anaphylaxis occurred. Conclusions: OIT is safe as a method of sesame allergy desensitization. Further studies are needed to determine which of the strategies used are optimal for children.

Methods:
Between 2011 and 2020, children presenting to seven EDs in five provinces were recruited as part of the Cross-Canada Anaphylaxis Registry (C-CARE). A standardized form documenting triggers, symptoms and management was collected. A logistic regression model was used to determine factors associated with requiring more than one epinephrine dose in the ED following a milk reaction. Results: Data were collected from 247 pediatric patients (median age 3.60, interquartile range (IQR) [1.10, 8.15]) presenting with milkinduced anaphylaxis. Among all, 93.9% of patients presented following oral ingestion of milk, 3.2% after cutaneous exposure. The symptoms most frequently experienced were urticaria (66.0%), angioedema (48.2%), pruritus (41.3%), gastrointestinal symptoms (38.1%) and breathing difficulty (36.8%). Epinephrine was used in 51.0% of patients outside the ED and used in 44.5% in the ED. Among 110 patients requiring epinephrine in the ED, 14 required multiple doses: 11 patients were given 2 doses, 3 were given 3 doses. Risk factors for multiple epinephrine doses were known allergy to eggs (adjusted odds ratio (aOR) 1.86 (1.53; 2.26)), to wheat (aOR 1.86 (1.53; 2.26)) as well as ingestion of milk in the form of baked goods (aOR 1.18 (1.01; 1.39)) when adjusting for age, sex and asthma. Conclusions: Consumption of milk from baked goods, known allergy to eggs and to wheat are associated with the need to use more than one dose of epinephrine for anaphylaxis in EDs. Prompt epinephrine use by caregivers when children are exposed to milk from baked goods is essential.
Background: Anaphylaxis is a systemic and life-threatening allergic reaction. Data are sparse regarding variations in anaphylaxis rates on a year-by-year basis. We aimed to assess changes in yearly rates of anaphylaxis in a pediatric Emergency Department (ED) in Montreal, Canada. Methods: Cases of anaphylaxis presenting to the Montreal Children's Hospital between April 2011 and May 2021 were recruited prospectively and retrospectively. Data were obtained via a standardized recruitment form. Descriptive analysis was used to assess the trend of anaphylaxis in relation to clinical triggers. Statistical significance was calculated using Pearson's chi-squared test. Results: Among 760,079 ED visits between April 2011 and May 2021, 2573 (34.95% of whom recruited prospectively) presented with anaphylaxis, The median age was 5.70 years (IQR: 2.20, 11.70), and 58.66% were males. The relative frequency of anaphylaxis cases with respect to ED visits doubled between 2011-2015, from 0.22 (95% CI, 0.19, 0.26) to 0.42% (95% CI, 0.38, 0.46). From 2015 to 2020 the rate was stable. Importantly, during the COVID-19 pandemic, beginning March 2020, the total absolute number of anaphylaxis and emergency cases declined, leading to a significant decrease in anaphylaxis cases by 24 cases per month(p < 0.05) and by 0.5% among ED visits (p < 0.05). Foods, (85.75%),drugs (2.81%) and venom (1.60%). Peanut (19.08%) and tree nuts (14.36%) were the major triggers of food-induced anaphylaxis. Most anaphylactic reactions were moderate (71.81%), defined as crampy abdominal pain, diarrhea, recurrent vomiting, hoarseness, "barky" cough, difficulty swallowing, dyspnea, moderate wheezing, and lightheadedness. Conclusions: The rate of anaphylaxis has plateaued over the last six years, representing increased awareness, modifications in food introduction strategies or lifestyle changes. The observed decrease in anaphylaxis during COVID-19 may reflect hesitancy in arrival for management in a hospital setting, given the similar decrease in ER visits. Background: Sesame is a major anaphylaxis food trigger and a priority allergen. We assessed the clinical characteristics and management of pediatric patients with sesame-induced anaphylaxis and identified factors associated with epinephrine treatment. Methods: Children with sesame-induced anaphylaxis to seven Emergency Departments (ED) in four Canadian provinces and one Emergency Medical Services (EMS) in Quebec's Outaouais region were enrolled in the Cross-Canada Anaphylaxis Registry (C-CARE). C-CARE includes nationwide anaphylaxis data from April 27, 2011-January 31, 2021. Data was obtained with standardized recruitment forms and included symptoms, severity, triggers, and management plan. Multivariate logistic regression was used to assess associations with epinephrine treatment before and in the ED. Results: Among 130 children presenting to Canadian EDs between 2011 and 2021 with sesame-induced anaphylaxis, 61.5% were males with mean age of 5.0 years (SD 4.9). Sesame-induced reactions accounted for 4.0% of all food-induced reactions. The most common sesame triggers were hummus/tahini (53.5%), bagel sesame grains (4.4%), bread (3.5%), and cookies (3.5%). Patients with previous knowledge of their allergy accounted for 37.7%. Epinephrine was used in 32.3% of cases prior to ED and 47.7% in the ED. Among all cases, 20.0% did not receive epinephrine. Almost half (50.8%) were referred to an allergist for evaluation. Patients most likely to be treated with epinephrine pre-hospital included those with a known allergy and males [adjusted Odds Ratio (aOR) 1.36 (95% CI 1.11, 1.68) and aOR 1.27 (95% CI 1.08, 1.50), respectively] with adjustment for age, severity, reaction location, and epinephrine prescription. Older patients were more likely to receive epinephrine treatment in the ED [aOR 1.02 (95% CI 1.00, 1.04)] with adjustment for sex, severity, and known allergy. Conclusions: In Canada, the major trigger of sesame-induced anaphylaxis is tahini, often found in hummus. Educational programs on prompt epinephrine use and increased product labelling policies are required to limit sesame reactions in the community. Background: Food allergy imparts a significant burden worldwide, albeit disproportionately affecting children and their families. Continued research supports the association between poor quality-of-life and food allergy, despite advances in related healthcare. Currently, little is understood about how healthcare providers describe standard practices for pediatric food allergy, and how limitations in healthcare structures may compromise quality of care. To better understand how pediatric food allergy care can be improved, we considered healthcare providers' perceptions of the current standard of care in order to identify gaps in professional knowledge and public resources specific to food allergy.

Methods:
We performed individual interviews (n = 6) and professionspecific focus groups (n = 2, involving 7 participants) of healthcare providers, based in Manitoba, Canada, who care for children with food allergies. Healthcare providers included pediatric allergists (n = 4), allergy nurse educators (n = 5), and clinical dieticians (n = 4). Interviews/focus groups were audio-recorded and transcribed verbatim. Data were analysed using thematic analysis via an inductive approach, from which we identified main themes. Results: We identified 3 main themes. The first theme, Bridging professional knowledge gaps, highlights areas where interviewees felt that additional support or training was needed. The second theme, Limitations within the current healthcare system, identifies barriers within the aforementioned professions that create obstacles in delivering superior patient care. Examples ranged from "enormous" waitlists to time constraints making psychological care "not feasible in [the] current scope of my practice". Lastly, Incorporating a multidisciplinary, patient-centered approach to pediatric food allergy care, lists the recommendations provided by our study participants on how they perceived professional practice shortcomings could be improved. Conclusions: Herein, healthcare providers collectively described standard practice limitations and systemic flaws within the field of pediatric food allergy care. Moreover, they advocated for improved public and professional food allergy education and a multidisciplinary approach to patient care. Background: Peanut allergy is the most common food allergy in Canadian children and accounts for a significant number of fatalities related to food allergy. Peanut desensitization in young children has been shown to be effective and safe. However, as children grow into adolescents, they encounter more difficulties and have greater risks for severe reactions. The primary aim of this study was to evaluate the safety of peanut desensitization in preschool and school-aged children. Methods: Children, up to 15 years of age, diagnosed with peanut allergy based on history and a positive peanut skin prick test were enrolled from academic and community allergic clinics. Patients underwent peanut desensitization on a four-week interval basis. Upon initial visit, children were introduced to a dose of 5-10mg of peanut flour or peanut puff and they gradually progressed to more concentrated forms of peanut protein (peanut butter). An endpoint of 2 teaspoons of peanut butter (4000 mg of peanut protein) was defined. An initial quality-of-life questionnaire and a daily symptom diary were distributed among parents. Demographics of the study population and adverse reactions were evaluated using R (v4.0.2). Results: From September 25, 2020 to June 10, 2021, 80 children were recruited for peanut desensitization. The mean age was 18 months and 55% were male. Atopic dermatitis (85.3%) and asthma (14.2%) were the main associated comorbidities. The most common co-allergies were egg (57.8%), milk (26.3%), and cashew (21%). At this point, one patient has reached 1 teaspoon of peanut butter. To date, among the 11105 total intake doses of peanut given, 150 non-anaphylactic reactions (4%) and 12 anaphylactic reactions (0.01%) were reported. No severe anaphylaxis occurred (defined as hypotension, cyanosis or loss of consciousness). Conclusions: Our study supports the safety of peanut desensitization using concentrated forms of peanut protein in preschool and older children, in real-world clinical practice.
Background: Approximately 20% of anaphylactic reactions occur in school settings. This observation is concerning because food allergy (FA) and anaphylaxis management vary by jurisdiction, and consequently, amongst teachers and school staff. Currently, there are no formal synthesis of published studies in this area. To address this gap, we aimed to report on the baseline FA and anaphylaxis management knowledge, and differences post-educational intervention amongst teachers and school staff. Methods: Guided by the PRISMA-Scoping Review statement, we conducted a search on February 19, 2021 using the OVID-MedLine, Scopus, PsycInfo databases for articles published in 2006 and beyond. Eligible English and French articles from North America, Europe and Australia were included. Title/ abstract screening were done for 2,010 articles, of which 77 were moved to full-texting by two independent reviewers (MS/KM). No third reviewer was needed to resolve conflicts. Reviewers for French articles (JP) were inconsistent with English ones. Results were reported descriptively and thematically. Results: Eight studies conducted pre-post educational intervention surveys. Four studies provided epinephrine autoinjector (EAI) training. Session topics included: FA definition, diagnosis, allergenic foods, symptom recognition, medications and EAI administration. Five (62.5%) studies reported participants previously had students with FA, while related training was variable (37-64%) among teachers and school staff. One study reported associated emotions with FA were "concern" and "anxiety". All studies reported better knowledge in teachers and school staff who received intervention, better FA-related attitudes and beliefs (12.5%), better self-efficacy and confidence levels (37.5%). Notably, 25% of studies demonstrated higher pre-post scores within teachers from economically-disadvantaged school areas. Conclusions: Teachers and school staff have more FA-related experiences than training. Standardized education sessions and EAI training may promote safe schools for individuals with food allergy. Moreover, training may provide teachers and school staff with confidence and self-efficacy to effectively prevent and manage FA emergencies in schools. Background: Oral food challenge (OFC) is the gold standard for diagnosis of food allergy. Its process is largely defined empirically and severe adverse reactions during OFC remain unpredictable. Methods: Placebo-controlled OFC was conducted as part of a series of Canadian multi-center oral immunotherapy trials to confirm allergy to four common food allergens, namely, hen's egg, cow's milk, peanut, and hazelnut. All food doses and corresponding times of dosing were documented as well as adverse reactions during OFC. Incremental doses over time were plotted to calculate the relative growth rate (RGR), a mathematical constant measuring the exponential dose increase for each OFC. The association between adverse reaction severity, defined by the number of epinephrine dose(s), and OFC process parameters including RGR was investigated using logistic regression. Results: A total of 142 positive challenges (18, 6, 91, and 27 for egg, hazelnut, milk, and peanut respectively) were recorded. In 19, OFC was stopped before the third challenge dose due to adverse reactions and none required multiple doses of epinephrine (p = 0.025, Fisher's exact test). In those involving at least three challenge doses (n = 123), mean RGRs for egg (n = 17), hazelnut (n = 6), milk (n = 76), and peanut (n = 24) OFCs were 2.1, 2.4, 3.7, and 2.4 respectively. In total, 28 patients received multiple doses of epinephrine, accounting for 5.6% (n = 1), 22.0% (n = 20), and 25.9% (n = 7) of OFCs for egg, milk, and peanut respectively. The RGR was associated with these severe adverse reactions (p = 0.004, adjusted odds ratio = 2.34, 95% CI 1.38-4.42).

Conclusions:
The RGR measures the intensity of dose increment for each OFC and can be used to better standardize OFC or to guide modification of OFC process parameters by administering smaller food doses at each step and/or by increasing interval time between doses, to make an OFC safer.
Background: It is not clear how the COVID-19-related changes in the price and availability of food affect families with food allergy. Therefore, the current study investigated how COVID-19 has impacted the foodrelated costs of higher and lower income households with food allergy. Methods: We recruited 102 households with at least one food-allergic member to complete an online survey that assessed their food shopping and preparation habits prior to and during the COVID-19 pandemic. Changes in direct (i.e., out-of-pocket) and indirect (i.e., loss of time) food costs were described using means +/− SDs. We also used multiple regression analyses to identify patient factors associated with cost changes. All analyses were stratified based on whether the respondent's monthly household income fell above or below the median value of $5830 (CAD). Results: Households in both income strata reported lower indirect shopping costs, but higher indirect food prepa-ration costs and direct grocery costs following the outbreak of COVID-19. Regression analyses indicated that lower income food-allergic families with difficulties finding their typical grocery products reported a greater post-COVID-19 increase in direct grocery costs in comparison to those without such difficulties (+$164.31 vs. − $31.94, p = 0.03). Results also revealed that lower income households with an allergy to milk, wheat, or eggs experienced a larger increase in indirect food preparation costs following COVID-19 relative to those with other food allergies (+$244.58 vs. +$20.28, p = 0.03). Lastly, higher income households who had difficulties finding their typical grocery items reported greater indirect shopping costs after the emergence of COVID-19 contrary to those without such difficulties (+$34.09 vs. − $69.80, p = 0.04). Conclusions: Findings suggest that food-related disruptions linked to COVID-19 affect higher and lower income households with food allergy differently. While more research is needed, the current findings may help inform programs aimed at promoting the well-being of households with food allergy.
Background: Canadian labelling regulations require priority allergens to be listed if used as a component of an ingredient; however, there are no such requirements for non-priority allergens. This difference suggests a gap in non-priority allergen labelling. We aimed to compare the burden of priority allergens only versus those with both priority and non-priority allergies in Canadian children with multiple food allergies. Methods: This study uses data from NUANCES: multidimeNsional bUrden of Allergies in CanadiaN ChildrEn and adultS, an online survey of adults/children with multiple food allergies. Our study population was restricted to children only. Families reporting a single food allergy were excluded. Quantitative data were described using n/N and %. This study was approved by The University of Manitoba Health Research Ethics Board (HS23109 (H2019:317)). Results: In our sample of 123, 42 (34.1%) children reported allergies to both priority and non-priority foods, while 81 (65.9%) were allergic to priority allergens only. Amongst those with priority and non-priority allergy, there were various non-priority allergens reported, with legumes predominating. Notably, 11/42 (26.2%) reported pea allergy. Of those with priority allergies only, milk was consistently the most burdensome allergy across all domains. In contrast, amongst those with both priority and non-priority allergies, milk allergy was reported to be most burdensome within the domains of anxiety, stress, and expense, albeit at significantly lower frequencies than reported by those with priority allergies only (i.e. stress: 23.5% vs. 48.5%, respectively [p = 0.02]). Non-priority allergens were identified as the most burdensome within the domains of wish for tolerance (p = 0.02), worry about eating out (p = 0.04), and most burdensome overall (p = 0.02). Conclusions: Caregivers of children with both priority and non-priority allergies report greater wish for tolerance, worry when eating out, and overall burden for non-priority allergens, but describe limited family anxiety and stress compared to those with priority allergies only. Background: The COVID-19 pandemic impacted allergy healthcare services by causing closure of clinics and movement towards virtual care. This shift occurred in our Food Immunotherapy Program. Our objective was to evaluate patient satisfaction of virtual Food Allergen Immunotherapy (FAIT), which has not been well characterized. Methods: All families who received virtual FAIT between April 2021 and June 2021 were asked to complete a satisfaction survey online. Participants used Likert scales from 1 to 5 for satisfaction and perception of safety. Participants provided free-text responses about the benefits and risks of a virtual program. Participants selected pReference for (1) In-person, longer wait time or (2) Virtual, shorter wait time. Median and Interquartile range were calculated for Likert scales.

Patient satisfaction with a virtual healthcare program for food allergen immunotherapy
We scanned the open-ended responses for themes. Overall pReference between in-person and virtual FAIT was measured with proportions. Results: 34 families completed the survey. The median for satisfaction was 5 (IQR: 5, 5). The median for perception of safety was 4 (IQR: 4, 5). Eliminating cost and time for commuting to appointments was the most reported benefit. Delayed medical attention in the event of severe reaction emerged as the most common perceived risk. 29 (85.3%) respondents indicated that they preferred virtual immunotherapy treatment with a shorter wait time over in-person with a longer wait time. Conclusions: Patient families are highly satisfied with a virtually supervised FAIT program, especially due to cost and time savings, and most feel it is safe. Most prefer virtual FAIT with a shorter wait time over in-person with a longer wait time. Comprehensive qualitative analysis is needed to better understand perceived risks and benefits. Data should be collected over a longer timeframe with a larger sample for continuous quality improvement and ensuring virtual FAIT is just as safe as an in-person program. Background: Peanut allergy is considered the most severe of all food allergies as it is the leading cause of fatal anaphylaxis. Evidence suggests that the allergenicity of peanuts is influenced by the method of peanut processing prior to consumption. The aim of this project is to develop alternative processing methods and evaluate their effect on the known peanut protein allergens and thus, peanut allergenicity. Methods: Peanuts were ground into a paste and dissolved in hexanes for defatting. Protein extracts from raw, roasted (150 °C, 30 minutes), and autoclaved (136 °C, 2.5 atm, 30 minutes) peanuts were used to quantify relative levels of protein allergens Ara h 2 and Ara h 8 via Western blot analyses and ELISA using antibodies specific for each allergen. Results: Similar levels of detection of Ara h 2 and Ara h 8 were observed in the raw and roasted peanut extracts as shown by Western blot and ELISA. Autoclaved extracts resulted in a decrease in Ara h 2 and Ara h 8 detection by approximately 50% and 100%, respectively, when compared to raw. The absence of signal in the Western Blot analysis indicates potential degradation of each allergen to different degrees in autoclaved peanut samples.

Conclusions:
The results display discrete levels of detection of two peanut protein allergens following autoclaving. Given the distinct clinical reactions associated with specific IgE for Ara h 2 and Ara h 8, these findings have potential for higher power in peanut allergy diagnosis and treatment.
Background: Recommendations for childhood peanut allergy prevention emphasize early dietary peanut introduction and continuous peanut consumption based on studies in high-risk children. Generalpopulation CHILD Cohort Study children had lower peanut allergy and sensitization with peanut introduction by age 12 months; importance of continuous peanut consumption requires further study. We examined associations between continuous peanut consumption and peanut sensitization at age 5 years. Methods: CHILD caregivers prospectively reported their child's peanut consumption at ages 6, 9, 12, 18, 24, 30, 36, and 60 months. They were not advised how or when to introduce peanut. Continuous peanut consumption was defined as having no more than one gap in reported peanut consumption after first introduction before 18 months, and two or fewer gaps thereafter until 5 years. All other patterns were considered transient. Sensitization (positive skin prick testing [SPT] > 2 mm larger than the negative control) was measured at 1 and 5 years. Per current guidelines, children at high risk of peanut allergy had egg sensitization or allergy and/or moderate-to-severe atopic dermatitis in their first year. Multivariable logistic regression examined the odds of peanut sensitization at 5 years in continuous versus transient eaters. Results: Of the 2440 children with SPT at 5 years, 2086 had complete peanut consumption data; 174 were high risk, 1800 consumed peanut continuously and 286 consumed transiently (including 189 who never consumed). Adjusting for maternal race, egg sensitization at 1 year, and study centre, children who consumed peanut continuously had reduced odds of peanut sensitization at age 5 years (OR 0.85, 95%CI: 0.83-0.86), even after excluding children who never consumed peanut (OR 0.88, 95%CI: 0.86-0.90) or after excluding high-risk children (OR 0.90, 95%CI: 0.88-0.91). Conclusions: General-population children with continuous peanut consumption after first introduction had reduced odds of peanut sensitization at age 5 years, even after excluding high-risk children.
Background: Peanut allergic individuals may be co-sensitized or coallergic to another legume(s), although Canadian data are sparse. Our aim was to describe the distribution of legume allergy, specifically peanut and soy (priority allergens in Canada), and lentil, pea, chickpea, or other unspecific non-priority legumes in Canada, with consideration to age. Methods: Caregivers of children (< 18 years) in Canada, with parentreported allergies to at least one of the following: peanut, soy, lentil, pea, chickpea, or unspecific non-priority legumes, were included in this study population. Data were collected as part of two different online studies, between 2019 and 2021, approved by the University of Manitoba Health Research Ethics Board. Data were described, then analysed using logistic regression, and adjusted for sex, age at diagnosis and total number of food allergies, with statistical significance set at p < 0.05. Results: Our study population included 115 children from all Canadian provinces, who were disproportionately boys (64.6%) and of which one-third were aged 6 or under. Nearly all (109/115; 94.8%) had peanut allergy, with lower prevalences of soy (18/115; 15.7%) and non-priority legumes (15/115; 13.0%). Most children had an epinephrine autoinjector (106/111; 95.5%) and had been diagnosed by an allergist (96/99; 98.0%). Specific to legume allergies, n = 85 children had mono-peanut allergy, n = 6 had mono-soy allergy, no children had non-priority legume allergy, n = 12 children had peanut+nonpriority legume allergy, n = 9 had peanut+soy allergy, and n = 3 had peanut+soy+non-priority legume allergy. Compared to children aged 6 or under, older children were significantly less likely to have peanut, plus soy or nonpriority legume allergy (OR 0.22; 95%CI 0.05-0.94, p = 0.04). Conclusions: In Canada, peanut allergy remains the most common legume allergy. However, allergy to peanut + at least one additional legume affects about 20% of children allergic to peanut, but disproportionately amongst young children. Background: Eosinophilic esophagitis (EoE) is diagnosed by biopsyproven eosinophilic infiltration of the esophagus in excess of 15 eosinophils per high power field. Skin prick testing (SPT) and in some cases, food patch testing (FPT), are commonly performed to help direct allergen avoidance. Characterization of EoE's atopic profile is variable. Methods: A retrospective chart review was conducted at a community allergy clinic of patients referred for allergy assessment in biopsyproven EoE. History of EoE symptoms, SPT IgE positivity to common foods and inhalants and FPT results were tracked. When available, follow-up endoscopic results were collected to determine trends in EoE phenotype outcomes. Results: Fifty patients were identified with biopsy-proven EoE. SPT was positive in 34/50 (68%), with the majority to inhalants. FPT was positive in 35/48 (73%). Combined SPT and FPT were negative in 3/50 (6%). Twenty-three of 48 (48%) were combined FPT and SPT positive, 12/48 (25%) were FPT-positive and SPT-negative, 10/48 (21%) were FPT-negative and SPT-positive and 3/48 (6%) were FPT-negative and SPT-negative. Twenty-five patients with EoE went on to a second endoscopy. Six patients displayed remission while 19 remained EoE-positive. Fourteen of the 19 (74%) were SPT-positive; 5/19 (26%) were SPT-negative. In addition, 15/19 (79%) were FPT-positive; 4/19 (21%) were FPT-negative. Conclusions: The majority (96%) of confirmed EoE patients displayed either an individual or combined allergic profile based on results of SPT and FPT. However, individual SPT or FPT was positive in 68-75% of EoE patients. Allergy evaluation results in the first and follow-up endoscopes remained similar on biopsy. A combined allergic evaluation will yield greater results in the potential allergic avoidance role in the management of EoE. The impact of the above allergic evaluation will be explored in a separate abstract. Background: Milk and egg ladders, or "food ladders", are tools designed to guide patients with IgE-mediated allergies through a stepwise introduction of increasingly allergenic forms of milk and egg in a home-based setting. Little data exists supporting food ladder use in clinical practice. This study aimed to adapt existing food ladders to reflect dietary practices in Canada, and determine safety of food ladders in Canada. Methods: Canadian allergists determined patient suitability to receive a food ladder in clinical management of milk or egg allergy 1 . Inclusion criteria included patient age < 18 years and a diagnosis of egg or milk allergy. Patients were provided with a survey link along with the relevant food ladder(s). Parents completed baseline and follow up surveys at 3 and 6 months. Descriptive statistics were obtained through REDCap. Results: Between January -June 2021, ten 3-month follow up surveys and five 6-month follow up surveys were completed; 9 (90%) patients were still using food ladders at 3-month follow up, and one had stopped due to unclear reasons. All 5 patients who completed follow up surveys at 6 months were still using food ladders. Three patients (30%; 2 on egg ladder, 1 on milk ladder), experienced minor skin or gastrointestinal tract symptoms. None required epinephrine or emergency department visits. Eight (89%) parents felt comfortable managing ladder progression at home, and 1 (12.5%) parent felt unsure. Conclusions: Preliminary data suggest food ladders may be a feasible, safe method for home-based dietary expansion in select milk and/or egg allergic children with mild IgE-mediated symptoms. Further evaluation is needed to confirm safety of food ladders. Background: Eosinophilic esophagitis (EoE) is diagnosed by biopsyproven esophageal eosinophil infiltration. It is characterized by a variable allergic profile, with skin-prick testing (SPT) and food-patch testing (FPT) commonly conducted to guide allergen avoidance. Proton-pump inhibitors (PPIs) or budesonide may also be considered to manage symptoms. Methods: A retrospective chart review was conducted at a community allergy clinic of patients referred for biopsy-proven EoE. History, SPT IgE-positivity, FPT results and treatments were tracked. When available, follow-up endoscopic and consultation results were collected to determine patterns in EoE outcomes.
If not follow-up scoped, follow-up data was available for 14 patients. Eleven patients displayed clinical improvement/control, with 4/11 (36%) on PPI/avoidance and 7/11 (64%) on avoidance diet alone. SPTpositivity was 82% and FPT-positivity was 64%. Three remained symptomatic, and on avoidance diet alone. SPT-positivity was 67% and FPT-positivity was 33%. Conclusions: The majority of patients practiced an avoidance diet alone with no PPI. Patients upon second endoscopy, both EoE-positive and negative, had been treated similarly. Allergic profiles were also similar across EoE-positive and negative patients. Upon follow-up consultation, clinically-improved and symptomatic patients had similar treatments and allergic profiles. These data suggest a reduced role for treatment and allergic profile in EoE improvement/control versus exacerbation, although it must be considered that clinically-improved patients may not seek/attend follow-up consultations/endoscopies. Background: The COVID-19 pandemic has increased levels of anxiety for many Canadians. However, patients with known allergies/immunological conditions have been particularly anxious regarding COVID-19 and related vaccinations. The purpose of this study is to describe patients with COVID-19 vaccine concerns who did not experience any reactions and explore the reactions that did occur. Methods: A retrospective chart review was performed for patients seen at an Allergy and Immunology clinic in Toronto, Ontario between December 2020 and June 2021. Patients were included if they spoke with staff regarding COVID-19 vaccine concerns or reported a reaction to one of the vaccines. Results: There were 41 patients (53.7% female) concerned about the COVID-19 vaccine who had no reaction. Approximately half received one dose (n = 19, 46.3%) of the vaccine. The mRNA vaccines were the most common (Pfizer-BioNTech n = 28, 68.3%; Moderna n = 4, 9.8%; not reported n = 6, 14.6%). Most common reasons for concern included history of urticaria (n = 11, 26.8%), adverse reaction to a vaccine or drug (n = 10, 24.4%), anaphylaxis (n = 7, 17.1%) or known polyethylene glycol allergy (n = 5, 12.2%). For those who experienced a vaccine reaction (n = 33, 90.9% female), 26 (83.9%) had a known allergy(ies) or immunological condition. The majority received the Pfizer-BioNTech vaccine (n = 26, 78.8%), followed by Moderna (n = 5, 15.2%) and AstraZeneca (n = 2, 6.1%). Approximately half of patients received one dose (n = 14, 42.4%; not reported n = 5, 15.2%). The most common reactions were urticaria (n = 12, 36.4%), paresthesia (n = 6, 18.2%), "COVID arm" (n = 4, 12.1%) and other cutaneous manifestations (n = 4, 12.1%). Majority of patients reported complete resolution of symptoms within a few days to weeks (n = 26, 78.8%), while seven (21.1%) have ongoing symptoms. Conclusions: From preliminary data, only 33 patients reacted to a COVID-19 vaccine. Although vaccine hesitancy is prevalent and risk of reaction is low, patients with allergy(ies)/immunological conditions may benefit from an allergist/immunologist consultation prior to vaccination. Conclusions: To our knowledge, this is the first study to analyze markers of autoimmunity in ventilated patients to predict mortality. The data provides a strong rationale to develop anti-DFS70 as a biomarker as well as investigate their protective mechanism against an autoimmune pathology. Background: Real-world safety of oral immunotherapy (OIT) across the pediatric age spectrum has not been well-studied. This is an exploratory analysis of the association between grade-2+ reactions and OIT when administered to children < 4 years old as compared to ≥4 years. Methods: OIT was administered through a community practice in Victoria, BC in children aged 0-18 who fulfilled previously defined inclusion criteria [1]. Patients underwent OIT buildup to 1-10 foods in clinic over the course of several weeks, to achieve a maintenance dose of 300mg per food. Symptoms of reactions were tracked and patients with grade-2+ [1] reactions were compared according to age at OIT start using a chi-squared test. As a secondary outcome, linear regression modelling was performed to determine the relationship between number of foods treated and grade-2+ reactions. Results: Between 2017 and 2021, 186 patients (median age: 5) started OIT, 23 (12.4%) of which had grade-2+ reactions during build-up. These reactions were experienced by 9% of patients < 4 years and 15% in ≥ 4 years (p = 0.48). The linear model found that incidence of grade-2+ reactions increased by 7.9% per food (R2 = 0.8551). Conclusions: Although preliminary, our data suggests that number of foods treated increases the risk of grade-2+ reactions during OIT buildup. Further research is needed to determine whether there is some association between age and increasing number of foods treated, or whether a delay between initial diagnosis and start of OIT may play a role in this increased risk. Additionally, factors such as starting dose, history of previous reactions, food combinations of concurrent OIT, and other factors should be further explored to improve safety outcomes for all patients. Background: Mast cells are tissue-resident sentinels that regulate responses to pathogens and allergens. They are critical for hypersensitivity reactions and typically activated in Th2 cytokine-rich environments during allergic disease. Mast cells respond to viruses by producing chemokines and type I and III interferons (IFNs). Clinical studies have investigated Th2 cytokine inhibitors, including IL-5 inhibitors, in asthma therapy 1-3 . However, the influence of IL-5 inhibition on mast cell responses to virus infection remains unclear. The effects of IL-5 or IL-5 inhibition on mast cell antiviral responses may be important in virus-associated exacerbation of asthma. Methods: Human cord-blood-derived mast cells from anonymized donors (n = 14; 12 donors) were isolated and pre-treated in culture medium with or without 10 ng/mL IL-5 for 48 hours. Cells were infected with OC43 coronavirus at 1.0 MOI, treated with poly(I:C), or left in culture medium (mock) for 24 hours. qPCR and Luminex analysis were performed to assess mRNA and protein levels for type I and III IFNs. Statistical analysis was performed using mixed-effects analysis with Sidak's multiple comparisons test. Results: Coronavirus infection or poly(I:C) treatment of mast cells resulted in significantly higher levels of IFNA2, IFNB1, and IFNL1 mRNA compared to respective mock treatments (p < 0.01-0.0001). Luminex analysis revealed that IFNα2 production was increased in IL-5-pretreated and non-pre-treated cells following poly(I:C) stimulation and following coronavirus infection of IL-5-pre-treated cells compared to controls (p < 0.001-0.0001). Interestingly, the enhancement of mRNA and protein expression following coronavirus infection or poly(I:C) treatment was significantly greater in IL-5-pre-treated compared to non-pre-treated mast cells for all targets (p < 0.05-0.001). Conclusions: IL-5-pre-treatment enhances the expression of type I and III IFN mRNAs by mast cells in response to coronavirus or poly(I:C), suggesting IL-5 may have an important role in mast cell antiviral responses. The mechanism by which IL-5 enhances mast cell IFN expression will be investigated further. Background: Interactions between immune cells are critical for their activation and effector function. Many immune cells reside within niches in the tissue microenvironment which are critical for their survival, proliferation, and activity. Traditional methods such as flow cytometry remove cells from their tissue environment for measurement at the single-cell level, and therefore capture neither cell-cell interactions nor cellular niches. This is typically overcome using immunofluorescence microscopy, which allows for in situ analysis but fails to capture heterogenous phenotypes as it is limited to the visualization of 7-8 markers simultaneously. IBEX (iterative bleaching extends multiplexity), an approach in which a specimen is stained with fluorescent antibodies, imaged, bleached, re-stained, and re-imaged, allows for visualization of a theoretically unlimited number of markers, potentiating highly multiplexed quantitative analysis of cellar phenotype, interactions, and tissue microenvironment. 1 Objective: Develop an IBEX multiplexed imaging panel to study the cells and molecules associated with food allergy. Methods: C57/Bl6 mice were immunized with ovalbumin (OVA) and alum intraperitoneally. Tissues were harvested, fixed, frozen, and sectioned for analysis. A panel of 60 antibodies was optimized for imaging. Images were captured using a Leica Stellaris 5 confocal microscope and analyzed with Ilastik and histoCAT. 1,2 Results: IBEX reliably detects major immune cell populations over several staining cycles. Staining immunized mesenteric lymph nodes with OVA-AF647 allowed detection of allergen-specific B cells (B220 + OVA + ). Lastly, staining for immunoglobulin allows visualization of B cell isotype, which is validated by the absence of IgG1 and IgE signal in IgG1 and IgE deficient mice, respectively.

Conclusions:
These results indicate that IBEX can be used to study major immune cell populations, B cell isotype, and allergen specificity in mouse models of food allergy. The use of this tool in allergic model systems will help better understand the spatial distribution of immune cells and potentially identify novel therapeutic targets. Background: Hypereosinophilia is a rare but significant condition, wherein eosinophils infiltrate cells, release inflammatory cytokines, and may lead to systemic organ and damage. It could precipitated by allergic diseases, infection, or hypersensitivity reactions and lead to rapid changes in mental status. However, the mechanism of central nervous system-related changes in patients with hypereosinophilic syndrome is still poorly understood. We aimed to provide a descriptive overview to synthesize current evidence in the literature.

Methods:
We conducted a review of the literature followed by a qualitative narrative synthesis following ENTREQ guidelines. Databases including PubMed/MEDLINE, EMBASE and Google Scholar were screened, and no time, setting, or language restrictions were imposed on the search strategy. Keywords in our search included: "eosinophilia", "mental", "consciousness", "psychological", "neurologic", "nervous system" and "HES". Primary research articles such as case studies, systematic reviews and meta-analyses, were included. Experimental and animal studies were excluded. Results: We identified 14 articles that met our inclusion criteria. Of the 14, ten discussed the presence of mental changes including stroke, temporal arteritis, leptomeningeal dissemination, memory deficits and dysarthria associated with hypereosinophilia. Three were systematic reviews identifying 143 cases and evaluating outcomes and discussing risk factors. Two major mechanisms including encephalopathy, which can result in states of confusion, and multiple embolic strokes and/or an increased presence of ischemic lesions in the brain accumulated the greatest mentions in literature. Cerebrovascular disease was an important co-morbidity as well as a significant risk factor characterized or mentioned by 12 studies.

Conclusions:
The evidence on changes in mental status in patients with hypereosinophilic syndrome is currently limited and of low quality involving retrospective studies, case studies, and reviews; thus, more rigorous studies are warranted.  [1]. A rotavirus immunization program for infants aged 2 and 4 months was implemented in British Columbia (BC) in January 2012 [2]. Prior to the Rotavirus vaccine, the first live vaccine was administered at 12 months. Adherence to immune workup recommendations prior to 2 months of age in patients with 22q11.2DS and adverse events following immunization is not known. Methods: A retrospective chart review of children diagnosed with 22q11.2DS in BC from January 1, 2012 to January 1, 2019 was conducted. Demographic, clinical, laboratory, and immunization data and adverse reactions to vaccines were obtained from hospital records. International pediatric consensus guidelines were used as a Reference to determine adherence to guidelines for immunologic workup [1]. Institutional research ethics board approval was obtained.
Results: Records of forty-two children with 22q11.2DS were reviewed and 39 children had immunization records available. Twenty-two out of 39 (56.4%) received at least one dose of a live attenuated rotavirus vaccine. No adverse events following immunization were noted. Ten (25.6%) infants received an immunological assessment prior to rotavirus vaccine administration, and six out of the ten (15.3%) had a CD4+ lymphocyte count higher than the cut-off of 500 × 10 6 cells/L to qualify for safe administration of a live attenuated vaccination yet did not receive the Rotavirus vaccine [3]. Patients with immunodeficiencies or patients who were taking immunoglobulin treatment were excluded from the initial studies. Uncertainty about vaccine safety contributes to vaccine hesitancy in some immunodeficient patients. Nevertheless, mass vaccination and rapid vaccine rollout is required to halt the pandemic crisis. We aim to report the safety outcome of patients on chronic immunoglobulin treatment who received COVID-19 vaccines from January to September 2021. Methods: Using the ONIT registry established at the Ottawa Hospital, Hamilton Health Sciences, and Unity Health Toronto, we will report on any medically attended adverse events following COVID-19 vaccination in patients who have been enrolled in the ONIT program.
Immunization, infection history, immunoglobulin treatment indication, dosage and infusion parameters are core data that are being collected at every virtual or in-person clinic visit.  Symptoms included throat tightness, dyspnea, tingling, and dizziness immediately after vaccination. One of the patients required treatment with epinephrine with subsequent need for emergency room visit. A two-step approach was taken to assess these patients for a potential allergic cause and exclude anxiety-induced reactions. Patients were blinded and initially skin tested to saline, observed for 15 minutes, and then assessed prior to skin testing to polyethylene glycol (PEG) as a suspected IgE mediated allergic trigger in the Pfizer-BioNTech vaccine.
Results: Both patients tested negative to saline. However, both experienced similar or worse symptoms as their initial reaction to Pfizer-BioNTech vaccination with dyspnea, pruritus, coughing, chest tightness, and dizziness during their allergy assessment. Notably, urticaria was absent.
One of the patients then went on to receive skin testing to PEG and tested negative. Both patients later received their second vaccination without issue. Conclusions: Two patients experienced "allergic-type" reactions after their first COVID-19 vaccine, not felt to be IgE mediated. Testing to saline elicited similar allergic-type symptoms, likely due to anxiety presenting as pseudo allergic reactions. Benefits of allergy consult and blinded testing to saline facilitated completion of vaccination.   (IDT) at non-irritating concentrations. 2 Currently there is no central database with published nonirritating concentrations of drugs available for skin testing. Methods: We began creating our database using the available nonirritating concentrations recommended in "Practical Guidance for the Evaluation and Management of Drug Hypersensitivity: Specific Drugs. " 3 We then expanded the database by conducting a comprehensive literature search in Medline in order to collect the known nonirritating drug concentrations for skin testing (SPT/IDT), patch testing for delayed hypersensitivities, desensitization protocols, and crossreactivity amongst drugs. When selecting articles, we gave pReference for recent articles, those that were relevant to our search, or from a top Immunology journal. Results: Our database contains References to over 500 articles and spans over 400 drugs, ranging from a wide variety of categories including antimicrobials, chemotherapeutics, biologicals, peri-operative agents, anticoagulants and coagulation factors. For each drug, the user is provided with SPT/IDT concentrations, patch testing concentrations, References to desensitization protocols that have been used, and allergic cross-reactivity amongst drugs. We created a prototype website to allow for users to easily interact with the database.

Conclusions:
The creation of this database with a collection of known drug concentrations for skin testing, patch testing, desensitization protocols and allergic cross-reactivity amongst drugs will allow physicians to access the information readily, effectively and efficiently in a busy clinic. Future directions include creating an online version of the database and a monitoring system where allergists can submit newly published non-irritating concentrations to the website.
Background: With the legalization of cannabis occurring in Canada and worldwide, the incidence of cannabis allergy is becoming increasingly recognized. [1] Reactions ranging from rhinitis to anaphylaxis with cannabis exposure have been described, highlighting the need to identify cannabis allergy. [2] Allergy to cannabis is felt to be due to Can s 3, a nonspecific lipid transfer protein, with several other cannabis allergens likely playing a role. [3] A prior study has demonstrated that Can s 3 is a reliable extract for skin prick testing and can identify positive individuals who are sensitized for cannabis allergy. [3] This extract is not yet readily available in most centers.
Methods: Here, we present a 4 patient case series of patients with respiratory symptoms with inhalational exposure to cannabis, as well as and one with contact urticaria with cannabis exposure. Patients were consented to a case series as part of our institution's protocol. Results: All four patients had positive skin prick testing for tree pollen, as well as their individual extracts of cannabis flower which they reacted to. One patient who had reacted to cannabis oil and flower had positive skin prick testing to only flower and not oil. Three among the five are continuing to use cannabis at risk, and have not yet presented with anaphylaxis.

Conclusions:
The use of cannabis flower for skin testing is a useful alternative to commercial extract testing. As cannabis use increases, it is prudent for allergists to include cannabis use and potential reactivity as a routine part of our history taking. Future research is needed in the utility and practicalities of cannabis challenges in the allergist's office.

The development and implementation of a proactive penicillin allergy de-labelling program for low risk inpatients at The Ottawa Hospital
Derek Background: Penicillin allergy is estimated to affect approximately 10% of hospitalized patients and is associated with numerous adverse outcomes. 1 Several allergy assessment modalities are available contingent upon the clinical history. Direct oral challenge has emerged as a safe, effective way of evaluating patients with low risk of penicillin allergy by history. 2 There is increasing support that proactively assessing penicillin allergy in hospitalized patients should be incorporated into antimicrobial stewardship programs. 3 Methods: We piloted a penicillin allergy de-labelling program where all inpatients were proactively identified, screened, and if deemed lowrisk by history (reactions greater than 10 years ago that were not severe cutaneous adverse reaction or anaphylaxis) administered a single 250mg amoxicillin oral challenge without preceding skin testing and monitored for 1 hour. The goal of the pilot program was to establish feasibility, resource utilization, and challenge outcomes. Results: Between April 16th and April 30th 2021 there were 66 patients admitted to the Ottawa Civic Hospital with penicillin allergy label on their Electronic Medical Record (EMR). 38 were excluded because of clinical instability, cognitive impairment or pregnancy. 9 patients were deemed to have a moderate or high-risk penicillin allergy. 19 patients were deemed low-risk and appropriate for a penicillin oral challenge. 14 consented and were challenged in hospital. All 14 patients tolerated the challenge and were de-labelled on their hospital EMR with a note sent to their family physician and home pharmacy. There were no adverse events during oral challenges. Conclusions: Our pilot study demonstrates that a proactive approach including direct oral challenge in low risk inpatients with penicillin allergy is a safe and feasible way to de-label patients. Our approach could be implemented more broadly as part of antimicrobial stewardship efforts across Canada.

Background:
The real-world Canadian practice pattern (PP) of diagnosis and management of eosinophilic esophagitis (EoE) is not well studied. The aim of this study is to report on any differences in practice and characterize adherence to guidelines. Methods: A cross-sectional online survey containing 15 questions was conducted among 43 gastroenterologists and allergists caring for pediatric and adult EoE patients from academic and community settings from multiple Canadian cities. Results: Of 43 respondents, around 90% were adult practitioners with 84% GIs and 14% allergists. 10% of participants preferred a proton pump inhibitors (PPIs) trial before diagnosing EoE, which is consistent with the proportion of responders who were not familiar with the new 2020 AGA JTF guidelines. Most participants performed biopsies in mid and distal (approx. 85%) over proximal segments (63%). More than 50% of participants used PPIs as first line therapy whereas 31% of respondents considered patient characteristics before choosing a therapy. When it came to steroid treatment, 50% preferred budesonide slurry, followed by fluticasone inhaler (34%). The use of scoring systems (EoEHSS, EEsAII-Pro, EREFS) while following patients was not common. Clinical and symptom remission had higher pReference over endoscopic remission in terms of treatment success. In contrast to other recent international PP survey results, a higher proportion (75%) of practitioners prescribed maintenance therapy for more than 50% of patients. For patients using maintenance therapy, a majority of specialists only performed scoping at 2 years or when patients experience symptoms.
Conclusions: There is a substantial variability among specialists in terms of diagnosis and management of EoE in Canada. While most of them were familiar with recent international guidelines, some standardization is still required on a recommended approach to tailor treatment choices, define treatment success and follow patients in order to improve outcomes and prevent recurrences and disease progression.

Methods:
We led a multidisciplinary team in British Columbia to develop a mobile point-of-care tool. The tool's algorithm is adapted from Canadian practice guidelines [1,2]. The tool was piloted locally in May 2021 and launched in June 2021. Our aims are to promote public education and reduce unnecessary referrals to allergists. By Oct 2021, we aim to have 300 user hits, achieve de-labeling for at least 50% of clinical encounters, and have the tool adopted by 6 health authorities by Oct 2021. Results: Our tool has been adopted at the BC Women's and Children's Hospital and Vancouver Island Health Authority. As of June 24, 2021, preliminary data shows: • 53 total user hits • 21 patients assessed to be low risk • 18 patients assessed not to be allergic based on history alone • 5 patients that tolerated oral challenges • 5 patients assessed to have a possible allergy • 44% of outcomes occurred in a clinical setting

Conclusions:
This mobile app is a unique and practical evidencebased tool to help assess and manage patients labeled with beta-lactam allergy. It represents an important step in removing barriers to the identification and removal of erroneous beta-lactam allergies. More work is required to achieve widespread awareness and usage of this tool in various practice settings.
Background: Chlorhexidine's excellent antimicrobial properties have resulted in its increasing use in healthcare settings. Proportionally, there has been an increase in type I and IV hypersensitivity reactions, including anaphylactic events. Many of these reactions occur in the preoperative or periprocedural context. This increase in allergic events is thought to be secondary to the rising use of chlorhexidine, and subsequent increase in sensitization. Case Presentation: An 11-year-old female with inflammatory bowel disease (IBD) developed two separate anaphylactic reactions during her monthly infliximab infusion. Initially she was referred for assessment of infliximab allergy. However, after careful history taking, it was noted that on both occasions, chlorhexidine was used as the antiseptic agent prior to IV insertion. Skin prick testing was positive to chlorhexidine at 14x8mm and negative for other possible causative agents. Although chlorhexidine had been used and tolerated during other infliximab infusions, our hypothesis was that on these two occasions the chlorhexidine did not fully dry before IV insertion, leading to iatrogenic injection of chlorhexidine and resulting anaphylaxis.
To confirm this hypothesis, timed skin prick testing was performed at 5-minute intervals as the chlorhexidine dried, with gradual decreasing wheal size and no wheal development after 15 minutes of drying. She was advised to avoid use of all chlorhexidine products in the future.
Conclusions: This case illustrates the importance of considering chlorhexidine in cases of procedural anaphylaxis, even if there is a history of tolerance. This case highlights opportunities for primary prevention at an institutional level by using alternative cleaning products for procedures with low risk of infection. Our center is working on implementing policies to discontinue use of chlorhexidine in patients requiring repeat procedures.

Statement of Consent
Written Informed Consent for this case report was obtained from the patient. Conclusions: BACH2 haploinsufficiency is increasingly being recognized as a possible cause of a syndrome of BACH2-related immunodeficiency and autoimmunity (BRIDA). Our patient has a long-standing history of immune dysregulation since childhood and it is possible that the identified BACH2 variant is pathogenic. With increased access to genetic testing, it is likely that more BACH2 variants will be identified in the future which will hopefully clarify the pathogenicity of this gene.

Statement of Consent
Written Informed Consent for this case report was obtained from the patient. Background: Neonatal nasal anomalies are rare. These anomalies include choanal atresia, congenital nasal pyriform aperture stenosis (CNPAS), nasolacrimal duct cysts, and congenital nasal septal deviation. Choanal atresia is often detected in the neonate with respiratory distress at birth requiring lifesaving airway placement, but when obstruction is unilateral, cases may go undetected until later in life.

Case Presentation:
A 3 year old female, ex 30 weeker triplet, is referred to the Allergy and Immunology clinic by her pediatrician for persistent nasal congestion, right sided rhinorrhea, difficulty feeding and intermittent right sided purulent discharge that started shortly after birth and persisted despite oral antihistamines, nasal sprays and recurrent antibiotics. She had multiple visits with ENT for lacrimal duct stenosis, otitis media, bacterial conjunctivitis & sinusitis. Subsequent rhinoscopy revealed right sided blockage. Landmark sinus CT confirmed choanal atresia. This was surgically repaired with complete relief of symptoms. Of note, due to prematurity, in the NICU she required a feeding support via NGT that, coincidentally, was repeatedly placed in the patent left nostril. Conclusions: Bilateral choanal atresia is detected at birth due to lifethreatening respiratory distress and requires lifesaving airway placement. However, when atresia is unilateral, it may remain undetected until later in life, such as in our 3 year old patient. During her NICU stay, nasogastric tubes for feeding were fortuitously placed in the patent left nostril each time, thereby evading the diagnosis of right-sided choanal atresia. Our patient had unilateral choanal atresia masquerading as chronic rhinitis. Choanal atresia is a rare congenital deformity resulting from failed recanalization of nasal fossae during fetal development. In 50% cases Choanal atresia is an isolated finding; but is a cardinal feature of CHARGE syndrome. Suspicion for congenital and non-congenital airway obstruction should be high in patients who do not improve with nasal steroids and antihistamines prompting further evaluation.

Statement of Consent
Written Informed Consent for this case report was obtained from the patient. Background: Vaccinations have been suggested to be a possible trigger for chronic urticaria. While acute urticaria following COVID-19 vaccination has been described in the literature, as of this writing there are no published cases of new onset chronic urticaria following vaccination. Case Presentation: A 55-year-old male who was previously healthy, with no history of atopy or urticaria, received his first dose of the AstraZeneca vaccine. He had no immediate symptoms following vaccination. By the next morning, he developed inducible urticaria with dermatographism. He had no fevers, chills, lymphadenopathy, or arthralgias. He was started on regular non-sedating antihistamines, with some effect. He had a normal complete blood count and differential. Tryptase, C3, and C4 levels, and total complement activity were normal. He was assessed by allergy and immunology approximately 8 weeks post-vaccination and continued to have ongoing inducible urticaria. Skin prick testing to 1:1 polyethylene glycol 3350 (Restorolax) and 1:1 polysorbate 80 (Refresh Ultra eye drops) were negative. He was advised to receive an mRNA-based COVID-19 vaccine for his second dose.
Conclusions: It is possible that the development of chronic urticaria in this patient may have been due to the use of an adenoviral vectorbased vaccine, given the association between viral infections and chronic urticaria. Clinicians should be cognisant that chronic urticaria may present following COVID-19 vaccination. As it is likely that similar presentations will be reported in the future, it is crucial that patients understand the non-allergic nature of chronic urticaria and that they are not at an elevated risk of an IgE-mediated allergic reaction following a second vaccination. Given that chronic forms of urticaria tend to be benign and may be self-limited, patients should be provided with the opportunity to consider the risks and benefits of a second dose.

Statement of Consent
Written Informed Consent for this case report was obtained from the patient. Background: Ocrelizumab is a form of anti-CD20 therapy with B cell depleting effects used in patients with multiple sclerosis (MS). This medication has been associated with an impaired antibody response to mRNA COVID-19 vaccinations. Amongst MS patients, receiving B cell depleting therapy has been identified as a risk factor for severe COVID-19 infection. Case Presentation: A 56-year-old physician with a history of MS and resolved chronic spontaneous urticaria was incidentally found to have hypogammaglobulinemia, with IgG levels ranging from 4.0 to 4.8 (normal range: 7.0-16.0). He had normal IgA and IgM levels. There was no history of recurrent sinopulmonary infections. Medications included aspirin and glatiramer initially, but he was later switched to ocrelizumab due to progression of his MS. He had protective measles, rubella, and varicella antibody titres. Initially, he had inadequate titres to mumps but after vaccination, he achieved protective levels. However, response to pneumococcal vaccination administered while on ocrelizumab was inadequate. His last dose of ocrelizumab was in October of 2020. He received his first dose of the Pfizer COVID-19 mRNA in January of 2021 and his second dose 41 days later. At 55 days post-vaccination, he had no evidence of COVID-19 antibody titres, measured by two different assays. In light of his hypogammaglobulinemia and poor vaccine responses, genetic analysis was performed. A pathogenic heterozygous variant in TNFRSF13B was identified, which is associated with autosomal recessive common variable immunodeficiency. Possession of a single allele may have contributed to the patient's presentation.
Conclusions: Clinicians should be aware that patients on ocrelizumab may have an inadequate response to COVID-19 vaccinations and that these patients are also at a higher risk of severe COVID-19 infection. Consideration should be given to attempting vaccination prior to initiating therapy if possible, or otherwise vaccinating near the end of dose cycles.

Statement of Consent
Written Informed Consent for this case report was obtained from the patient. Background: Chocolate is produced by fermenting, roasting and grinding cacao beans from the fruit pod of the cacao tree. Cocoa powder is made by removing 75% of the cocoa butter and drying the residue. Cocoa powder contains carbohydrates, fat and protein. Allergic reactions to cocoa are extremely rare. We report a case of an allergic reaction to cocoa in a young girl.

Case Presentation:
A six year old female with multiple food allergies (kiwi, tree nuts, wheat and egg) ingested a drink consisting of one teaspoon of Hershey's ™ Cocoa mixed with boiled milk and sugar. After two to three sips she complained of abdominal pain and she developed facial urticaria. There were no other symptoms. She was given an oral antihistamine and her symptom improved within two hours.
Although an epinephrine auto injector was available, it was not used. An epicutaneous test to the Hershey's Cocoa resulted in a 9 mm wheal. The reaction was reported to Canadian Food Inspection Agency. The cocoa powder was tested for contamination and found to be free of wheat, egg and tree nuts. There was no test available for kiwi. An epicutaneous test to a different brand of cocoa powder (Camino ™ ) was subsequently performed and was also positive with a 9 mm wheal. Epicutaneous tests to both cocoa powders were negative in a control subject.
Conclusions: Chocolate/cocoa can be a food allergen. While many allergic reactions to chocolate have been attributed to contamination with other food allergens, we believe that this demonstrates a true cocoa allergy. Isolated chocolate/cocoa allergy should be considered in those individuals reacting to chocolate/cocoa-containing food products.

Statement of Consent
Written Informed Consent for this case report was obtained from the patient.

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The use of dupilumab in severe atopic dermatitis during pregnancy Nabeel Akhtar 1  Background: Atopic dermatitis (AD), is a chronic inflammatory skin disorder that manifests with severe pruritis. In pregnancy, AD is the most common skin disease accounting for 36-59% of all dermatoses. The rising prevalence of AD poses a significant economic and health burden. Current treatment options for moderate to severe AD in