Tree Nut-Induced Anaphylaxis in Canadian Emergency Departments: Rate, Clinical Characteristics and Management

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.

Food Allergy Education and Management in Early Learning and Childcare Centres: A Scoping Review on Current Practices and Gaps

Anaphylaxis has occurred in preschools/schools yet there are no consistent food allergy (FA) management practices in early learning and childcare centres (ELCC) across jurisdictions. Presently, there are no reviews that have synthesized FA-related knowledge and management practices within ELCC. We aimed to perform a scoping review of FA management in ELCC, and report on perceived gaps or barriers. A PRISMA-ScR-guided search was conducted for North American, European and Australian articles in English/French in the OVID-MedLine, Scopus, and PsycInfo databases. Two independent reviewers screened the titles/abstracts of 2010 articles and full-text screened 77 articles; 15 of which were specifically related to ELCC. If the two reviewers could not agree to the relevance of a given study, a third reviewer provided guidance. This third reviewer also screened French articles. Thematic and descriptive reports of the studies were presented. We reported solely on pre-Coronavirus Disease pandemic ELCC studies. We included ten articles in this review, which provide evidence that ELCC staff have variable baseline knowledge, comprehension, experience, and practices in place to manage FA. ELCC staff also have limited FA-related training and experience regarding administration of epinephrine auto-injectors (EAI). Emergency Anaphylaxis Plans (EAP) were described in four studies. One study reported the parental influence on the site's food purchasing and FA management. Three studies provided educational interventions, which demonstrated increased and sustained FA-related knowledge and confidence post-intervention. Participants deemed the training beneficial and desired annual training and more FA resources to be available. Across jurisdictions, ELCC staff have provided care and administered EAI in emergencies, but training remained variable. Communication and care planning amongst ELCC staff, and parents, is crucial. Annual education, available EAI and EAPs are tools necessary for effectively managing emergencies.

Epinephrine treatment of food-induced and other cause anaphylaxis in United States and Canadian Emergency Departments: a systematic review and meta-analysis

INTRODUCTION

Studies from more than 10 years ago showed epinephrine treatment of food-induced anaphylaxis in the emergency department (ED) was unacceptably low. We investigated whether epinephrine treatment of food-induced and other cause anaphylaxis in United States and Canadian EDs has changed over time.

METHODS

Guided by a health sciences librarian, we performed a systematic search in Medline, Embase, and Web of Science on 11 January 2023. We included observational studies that reported epinephrine use to treat anaphylaxis in the ED. We stratified by anaphylaxis etiology (food-, venom-, medication-induced, or any cause). Associations between year and epinephrine use were tested using Spearman correlation and proportional meta-analysis.

RESULTS

Of 2458 records identified in our initial search, 40 met inclusion criteria. Of these, 14 examined food-induced, 4 venom-induced, 0 medication-induced, and 24 any cause anaphylaxis. For epinephrine treatment of food-induced anaphylaxis in the ED, among studies using similar definition of anaphylaxis, meta-analysis showed a pooled value of 20.7% (95% CI 17.8, 23.8) for studies performed >10 years ago and 45.1% (95% CI 38.4, 52.0) from those in the last 10 years. For anaphylaxis of any cause, there was no change over time, with a pooled value of 45.0% (95% CI 39.8, 50.3) over the last 10 years.

DISCUSSION

Epinephrine treatment of food-induced anaphylaxis in the ED has increased over time. There was no clear change for anaphylaxis of any cause. Over the last 10 years, approximately 45% of ED patients with anaphylaxis received epinephrine. A limitation of the evidence is heterogeneity in anaphylaxis definitions.

Real-World Safety Analysis of Preschool Tree Nut Oral Immunotherapy

BACKGROUND

Our group previously described preschool peanut oral immunotherapy (OIT) in a real-world, multicenter setting, suggesting that this therapy is safe for most preschoolers.

OBJECTIVE

To examine the safety and tolerability of tree nut (TN) OIT in preschoolers in the real world.

METHODS

As part of a Canada-wide quality improvement project, TN-OIT (cashew/pistachio, walnut/pecan, hazelnut, almond, and macadamia nut) was performed in preschoolers who had (1) a skin prick test wheal diameter greater than or equal to 3 mm or a specific IgE level greater than or equal to 0.35 kU/L and a convincing objective IgE-mediated reaction or (2) no ingestion history and a specific IgE level greater than or equal to 5 kU/L. Dose escalations were performed every 2 to 4 weeks till a maintenance dose of 300 mg of TN protein was reached. Symptoms were recorded and classified using the modified World Allergy Organization Subcutaneous Immunotherapy Reaction Grading System (1, mildest; 5, fatal).

RESULTS

Of the 92 patients who started TN-OIT from 2018 to 2021, 79 (85.9%) underwent single-food TN-OIT and 13 (14.1%) underwent multifood TN-OIT to 2 (10.8%) or 3 (3.3%) TNs. Eighty-nine (96.7%) patients reached maintenance, and 4 (4.3%) dropped out. Sixty-five (70.7%) patients experienced reactions during buildup: 35 (38.0%) grade 1 reactions, 30 (32.6%) grade 2 reactions, no grade 3 or 4 reactions, and 2 (2.17%) received epinephrine.

CONCLUSIONS

Preschool TN-OIT in a real-world, multicenter setting appears safe and tolerable, with results comparable with our previously reported peanut OIT findings.

Tree nut allergy: a systematic review

PURPOSE OF REVIEW

Systematic scoping review, focusing on randomized clinical trials of recent research addressing tree nut allergy.

RECENT FINDINGS

This review addresses published, unpublished, and re-analyzed studies on tree nut allergy definition, epidemiology, etiology, diagnosis, prognosis, and therapy.

SUMMARY

The importance of tree nut allergy spans nations, economies, and cultures. While broad themes in epidemiology, etiology, diagnosis, prognosis, and therapy are emerging, the next major advance in tree nut allergy will require large, robust studies to deliver results important to patients and families.