Findings of a new study into severe allergic reactions offer a sobering warning to people allergic to tree nuts and, more broadly, could lead to quicker diagnoses in emergency care for people with all anaphylactic allergies.
The McGill University-led study by Dr. Moshe Ben-Shoshan's team found that drinking alcohol was linked to more severe reactions in nut allergies. They also raise the possibility that nut-flavoured alcoholic drinks, even those made with artificial flavouring, could still expose people to trace allergens and increase the risk of severe reaction.
More broadly, the study found patterns between the triggers and symptoms of anaphylaxis, an allergic reaction that can be fatal within minutes if untreated.
Food was found to be the most common trigger, responsible for over half of cases. Among these, tree nuts stood out for their strong link to throat tightness compared to other allergens. Reactions from the venom of insect stings were more likely to trigger heart-related problems like a decrease in blood pressure.
Bridging data gaps in adult anaphylaxis
Anaphylaxis is most often caused by food, bug bites or medications. While doctors often treat it effectively with epinephrine, the authors say they rarely understand why certain triggers cause specific symptoms, a knowledge gap that can delay diagnosis and treatment.
"For doctors, spotting patterns could mean faster, life-saving treatment in emergencies. For people with allergies, understanding the role of alcohol and other triggers can help them make safer choices," said lead author Roy Khalaf, a fourth-year medical student in McGill's Faculty of Medicine and Health Sciences.
"With the holiday season's abundance of nut-based treats and specialty beverages, the risk of accidental exposure to allergens requires careful attention," he said.
The findings may also have implications for labelling practices in the food and beverage industry, he added, emphasizing the importance of clear allergen information to protect consumers.
The study, published in International Archives of Allergy and Immunology, is one of the first large-scale Canadian efforts to investigate anaphylaxis in adults, an area the researchers say lacks data. They analyzed data from over 1,100 cases treated in Canadian emergency rooms over 10 years.
Next, the team aims to explore milder reactions outside of emergency care and investigate the connection between nuts and alcohol to improve allergy management.
The study was a collaborative effort orchestrated by Dr. Ben-Shoshan, Assistant Professor, Division of Allergy and Immunology and Clinical Dermatology, Montreal Children's Hospital, McGill University Health Centre (MUHC). It included researchers from the University of Calgary, the University of British Columbia, Memorial University, McMaster University, the University of Toronto, and the University of Manitoba.
About the study
"Symptomatology and Management of Adult Anaphylaxis according to Trigger: A Cross-Sectional Study" by Roy Khalaf et al., was published in International Archives of Allergy and Immunology. It was conducted without external sponsorship or funding.
