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.

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.

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.

Assessing Pediatric Cephalosporin Allergic Reactions Through Direct Graded Oral Challenges

BACKGROUND

Cephalosporins, β-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.

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 sparce regarding tree nut-induced anaphylaxis (TNA).

OBJECTIVE

We aimed to characterize rate, clinical characteristics, and management of TNA in children (0-17 years old) across Canada, and assess factors associated with severe reactions and epinephrine use.

METHODS

Between April 2011 and May 2020, data were collected on children presenting to five emergency departments (EDs) 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 years [Interquartile range (IQR): 2.5-9.5] and 65.4% were males. 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% CI, 1.6%-27.6%)] versus Ontario and Quebec, whereas pistachio-induced anaphylaxis was more common in Ontario and Quebec [6.3% difference (95% CI, 0.5%-12.2%)]. Pre-hospital and ED intramuscular (IM) epinephrine administration was documented in only 35.2% and 52.4% of cases, respectively. Severe reactions were more likely among males [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 due to differences in lifestyle (higher prevalence of Asian ethnicity in British Columbia versus Arabic ethnicity in Ontario and Quebec). IM epinephrine underutilization urges for EAI stocking in schools and restaurants, patient education, and consistent policies across Canada.

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.

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.

The International/Canadian Hereditary Angioedema Guideline

This is an update to the 2014 Canadian Hereditary Angioedema Guideline with an expanded scope to include the management of hereditary angioedema (HAE) patients worldwide. It is a collaboration of Canadian and international HAE experts and patient groups led by the Canadian Hereditary Angioedema Network. The objective of this guideline is to provide evidence-based recommendations, using the GRADE system, for the management of patients with HAE. This includes the treatment of attacks, short-term prophylaxis, long-term prophylaxis, and recommendations for self-administration, individualized therapy, quality of life, and comprehensive care. New to the 2019 version of this guideline are sections covering the diagnosis and recommended therapies for acute treatment in HAE patients with normal C1-INH, as well as sections on pregnant and paediatric patients, patient associations and an HAE registry. Hereditary angioedema results in random and often unpredictable attacks of painful swelling typically affecting the extremities, bowel mucosa, genitals, face and upper airway. Attacks are associated with significant functional impairment, decreased health-related quality of life, and mortality in the case of laryngeal attacks. Caring for patients with HAE can be challenging due to the complexity of this disease. The care of patients with HAE in Canada, as in many countries, continues to be neither optimal nor uniform. It lags behind some other countries where there are more organized models for HAE management, and greater availability of additional licensed therapeutic options. It is anticipated that providing this guideline to caregivers, policy makers, patients, and advocates will not only optimize the management of HAE, but also promote the importance of individualized care. The primary target users of this guideline are healthcare providers who are managing patients with HAE. Other healthcare providers who may use this guideline are emergency and intensive care physicians, primary care physicians, gastroenterologists, dentists, otolaryngologists, paediatricians, and gynaecologists who will encounter patients with HAE and need to be aware of this condition. Hospital administrators, insurers and policy makers may also find this guideline helpful.

Evaluation of Prehospital Management in a Canadian Emergency Department Anaphylaxis Cohort

BACKGROUND

Studies assessing the use of antihistamines and corticosteroids for the treatment of anaphylaxis have not supported a conclusive effect.

OBJECTIVE

To assess prehospital management of anaphylaxis by measuring the effect of epinephrine use compared with antihistamines and corticosteroids on negative outcomes of anaphylaxis (intensive care unit/hospital ward admission, multiple doses of epinephrine in the emergency department [ED], and intravenous fluids given in the ED).

METHODS

The Cross-Canada Anaphylaxis Registry is a cohort study that enrolls anaphylaxis cases presenting to EDs in 5 Canadian provinces over a 6-year period. Participants were recruited prospectively and retrospectively and were excluded if the case did not meet the definition of anaphylaxis.

RESULTS

A total of 3498 cases of anaphylaxis, of which 80.3% were children, presented to 9 EDs across Canada. Prehospital treatment with epinephrine was administered in 31% of cases, whereas antihistamines and corticosteroids were used in 46% and 2% of cases, respectively. Admission to the intensive care unit/hospital ward was associated with prehospital treatment with corticosteroids (adjusted odds ratio, 2.84; 95% confidence interval [CI], 1.55, 6.97) while adjusting for severity, treatment with epinephrine and antihistamines, asthma, sex, and age. Prehospital treatment with epinephrine (adjusted odds ratio, 0.23; 95% CI, 0.14, 0.38) and antihistamines (adjusted odds ratio, 0.61; 95% CI, 0.44, 0.85) decreased the likelihood of receiving multiple doses of epinephrine in the ED, while adjusting for severity, treatment with corticosteroids, asthma, sex, and age.

CONCLUSIONS

Prompt epinephrine treatment is crucial. Use of antihistamines in conjunction with epinephrine may reduce the risk of uncontrolled reactions (administration of 2 or more doses of epinephrine in the ED), although our findings do not support the use of corticosteroids.

Emergency Management of Anaphylaxis Due to an Unknown Trigger: An 8-Year Follow-Up Study in Canada

BACKGROUND

Anaphylaxis due to unknown trigger (AUT) is anaphylaxis not explained by a proved or presumptive cause or stimulus at the time of the reaction. Research describing the management and follow-up of AUT is limited.

OBJECTIVE

To assess and compare the demographic and clinical characteristics and the management of adult and pediatric AUT cases across Canada.

METHODS

Participants were identified between 2011 and 2018 in emergency departments at 8 centers across Canada as part of the Cross-Canada Anaphylaxis Registry. A standardized form documenting the reaction and management in children and adults was completed. Patients were contacted for follow-up to determine assessment by an allergist.

RESULTS

A total of 295 AUT cases (7.5%) were recruited among 3,922 cases of anaphylaxis. In the prehospital setting, children (adjusted odds ratio [aOR], 1.20; 95% CI, 1.05-1.37) and those with a known food allergy (aOR, 1.14; 95% CI, 1.02-1.28) were more likely to receive treatment with epinephrine. Children were also more likely to be assessed by an allergist after their reaction (aOR, 1.43; 95% CI, 1.13-1.81) and were more likely to have an identified trigger for their reaction (aOR, 1.35; 95% CI, 1.07-1.70). Among patients contacted for follow-up, food was identified as the cause of reaction in 11 of 76 patients. A new food allergy was diagnosed in 4 patients (2 children and 2 adults).

CONCLUSIONS

Our findings highlight important differences between management and follow-up of adult and pediatric AUT cases. It is crucial to follow up all cases of AUT and establish appropriate treatment and management guidelines.

Non-IgE-mediated food hypersensitivity

Non-immunoglobulin E (IgE)-mediated food hypersensitivity includes a spectrum of disorders that predominantly affect the gastrointestinal tract. This review will focus on the following more common non-IgE-mediated food hypersensitivity syndromes: food protein-induced enterocolitis syndrome (FPIES), allergic proctocolitis (AP), food protein-induced enteropathy (FPE) and celiac disease. FPIES, AP and FPE typically present in infancy and are most commonly triggered by cow’s milk protein or soy. The usual presenting features are profuse emesis and dehydration in FPIES; blood-streaked and mucousy stools in AP; and protracted diarrhea with malabsorption in FPE. Since there are no confirmatory noninvasive diagnostic tests for most of these disorders, the diagnosis is based on a convincing history and resolution of symptoms with food avoidance. The mainstay of management for FPIES, AP and FPE is avoidance of the suspected inciting food, with periodic oral food challenges to assess for resolution, which generally occurs in the first few years of life. Celiac disease is an immune-mediated injury caused by the ingestion of gluten that leads to villous atrophy in the small intestine in genetically susceptible individuals. Serologic tests and small intestinal biopsy are required to confirm the diagnosis of celiac disease, and management requires life-long adherence to a strict gluten-free diet.

The Risk of Recurrent Anaphylaxis

OBJECTIVES

To determine the recurrence rate of anaphylaxis in children medically attended in an emergency department (ED), we performed a prospective cohort study to evaluate prehospital and ED management of children with recurrent anaphylaxis and to assess factors associated with recurrent anaphylaxis.

STUDY DESIGN

As part of the Cross-Canada Anaphylaxis Registry, parents of children with anaphylaxis identified prospectively in 3 EDs and through an emergency medical response service were contacted annually after presentation and queried on subsequent reactions. Cox regression analysis determined factors associated with recurrence.

RESULTS

Among 292 children who were registered as having had medical attended anaphylaxis, 68.5% completed annual follow-up questionnaires. Forty-seven patients experienced 65 episodes of anaphylaxis during 369 patient-years of follow-up. Food was the trigger in 84.6% of cases, and epinephrine was used in 66.2%. In 50.8%, epinephrine was used outside the health care facility, and 81.7% were brought to a health care facility for treatment. Asthma, reaction triggered by food, and use of epinephrine during the index episode increased the odds of recurrent reaction. Patients whose initial reaction was triggered by peanut were less likely to have a recurrent reaction.

CONCLUSIONS

We report a yearly anaphylaxis recurrence rate of 17.6% in children. There is substantial underuse of epinephrine in cases of anaphylaxis. Educational programs that promote effective avoidance strategies and prompt use of epinephrine are required.

Assessing the Diagnostic Properties of a Graded Oral Provocation Challenge for the Diagnosis of Immediate and Nonimmediate Reactions to Amoxicillin in Children

IMPORTANCE

The diagnostic properties of a graded provocation challenge (PC) among children presenting with a rash in the course of amoxicillin treatment are currently unknown.

OBJECTIVE

To assess the accuracy and the negative predictive value of the PC in a cohort of children referred with suspected allergy to amoxicillin.

DESIGN, SETTING, AND PARTICIPANTS

A cohort study was conducted between March 1, 2012, and April 1, 2015, at the allergy clinic of the Montreal Children's Hospital, Montreal, Quebec, Canada. All children referred with suspected allergy to amoxicillin were approached. In addition, 346 eligible children were followed up to assess reactions to subsequent use of amoxicillin at the time of illness in cases with negative PC results. Data were collected on clinical characteristics, suspected antibiotic exposure, personal and first-degree relatives' comorbidities, and history of atopy and management of the reaction. Univariate and multivariate logistic regressions were compared to determine factors associated with immediate and nonimmediate reactions to the PC.

INTERVENTIONS

All children had a graded PC.

MAIN OUTCOMES AND MEASURES

Reactions to the graded PC, the negative predictive value of the PC for nonimmediate reactions, and factors associated with immediate and nonimmediate reactions to the PC.

RESULTS

A total of 818 children were assessed (median age, 1.7 years [interquartile range, 1.0-3.9 years]; 441 [53.9%] male). Among all participants, 770 (94.1%) tolerated the PC, 17 (2.1%) developed mild immediate reactions, and 31 (3.8%) developed nonimmediate reactions. The graded PC had a specificity of 100.0% (95% CI, 90.9%-100.0%), a negative predictive value of 89.1% (95% CI, 77.1%-95.5%), and a positive predictive value of 100.0% (95% CI, 86.3%-100.0%). Among all 346 participants eligible for annual follow-up, 250 (72.3%; 95% CI, 67.2%-76.8%) responded, 55 of whom received subsequent full treatment with amoxicillin; 49 of these 55 participants (89.1%) reported tolerance to subsequent full treatment with amoxicillin, while 6 (10.9%) developed nonimmediate cutaneous reactions. History of a reaction occurring within 5 minutes of exposure was associated with immediate reactions to the PC (adjusted odds ratio = 9.6; 95% CI, 1.5-64.0), while a rash that lasted longer than 7 days (adjusted odds ratio = 4.8; 95% CI, 1.4-16.4) and parental history of drug allergy (adjusted odds ratio = 3.0; 95% CI, 1.3-6.8) were associated with nonimmediate reactions to the PC.

CONCLUSIONS AND RELEVANCE

Graded PCs provide an accurate and safe confirmatory test for skin-related reactions to amoxicillin. Further studies are required to assess factors associated with the PC outcome groups.

Broadband ringdown spectral photography

A new technique that enables frequency-resolved cavity ringdown absorption spectra to be obtained over a large optical bandwidth by a single laser shot is described. The technique, ringdown spectral photography (RSP), simultaneously employs two key principles to record the time and frequency response of an optical cavity along orthogonal axes of a CCD array detector. Previously, the principles employed in RSP were demonstrated with narrow-band laser light that was scanned in frequency [Chem. Phys. Lett. 292, 143 (1998)]. Here, the RSP method is demonstrated using single pulses of broadband visible laser light. The ability to obtain broad as well as rotationally resolved spectra over a large bandwidth with high sensitivity is demonstrated.

Control of group C meningococcal disease in Australian aboriginal children by mass rifampicin chemoprophylaxis and vaccination

An outbreak of 12 cases of meningitis, 11 caused by Neisseria meningitidis serogroup C, occurred at Doomadgee from September, 1990, to April, 1991. The incidence of meningitis was 17.55/10(3) person-years. Only children aged 1-10 years were affected. In October, 1990, or shortly thereafter, 473/509 children aged between 1 and 15 years inclusive had one dose of Mencevax AC. From the time of vaccination until April, 1991, a further eight cases occurred, six in vaccinated children. Vaccine efficacy in 1-15 year olds was calculated as 77%. Despite this, in April, 1991, the prevalence of antibody to group C polysaccharide in vaccinated children (78%) was not significantly different from that in unvaccinated children and adults. 46 nonresponders were revaccinated, and, in February, 1992, 78% had antibodies to group C polysaccharide. In April, 1991, an estimated 3.0% of the population had group C organisms, carriage being directly related to household crowding. In June, 1991, 2 months after mass prophylaxis with rifampicin, none of these individuals were carriers. In October, 1991, the carriage rate of group C organisms was 0.64%. There have been no further cases caused by the epidemic strain. Although uncrowded housing is a basic need, mass chemoprophylaxis and two doses of vaccine for children should be used in similar outbreaks.

Selective uptake of 99mTc complexes and 67Ga in acutely infarcted myocardium

The suitability of various radiopharmaceuticals (99mTc-tetracycline analogs, 99mTc-glucoheptonate, 99mTc-diphosphonate, and 67Ga-citrate) for use in imaging acute myocardial infarction was assessed by determining their biologic distributions in experimentally infarcted dogs. The highest infarct-to-normal myocardial concentration ratio was found with 99mTc-diphosphonate (27.9:1); the highest infarct-to-liver ratio was also found with 99mTc-diphosphonate (15.9:1). The infarct-to-bone ratio, however, was 0.4:1 with 99mTc-diphosphonate. There was an excellent positive linear correlation between blood-flow reduction and uptake of the radiopharmaceutical after a threshold reduction in blood flow with 99mTc-glucoheptonate and 99mTc-tetracycline. Technetium-99m-tetracycline accumulated only in infarcted tissue while 99mTc-diphosphonate was increased in both ischemic and infarcted tissue. Thus, 99mTc-diphosphonate has characteristics best suited for scintigraphic imaging. Since 99mTc-tetracycline accumulates only in infarcted tissue, however, this tracer more accurately defines the size of an acute infarction.