Anaphylaxis is a life-threatening allergic reaction that occurs when the immune system overreacts to a trigger, such as food, drugs, or insect stings. Symptoms can escalate quickly, leading to difficulty breathing, a drop in blood pressure, and swelling of the throat, requiring immediate medical intervention. For people with severe allergies, rapid access to treatment can mean the difference between life and death.
A recent study has shed light on a concerning factor that can worsen allergic reactions: Alcohol. A team of researchers at McGill and other Canadian universities found that people with nut allergies who consumed alcohol experienced more severe symptoms. Alcohol can act as a cofactor, meaning it enhances the body’s allergic response.
Roy Khalaf, a fourth-year medical student at McGill, worked on this study under the mentorship of Dr. Moshe Ben-Shoshan at the Research Institute of the McGill University Health Centre’s Infectious Diseases and Immunity in Global Health Program. Khalaf analyzed over 1,100 adult cases of anaphylaxis across Canada to examine the severity of reactions triggered by different allergens.
Food-induced anaphylaxis was the most common trigger, responsible for over 50 per cent of emergency department visits related to severe allergic reactions. Among food-related cases, peanuts and tree nuts emerged as the most frequent culprits, with tree nuts linked to particularly severe symptoms.
Tree nut-induced anaphylaxis stood out due to its high prevalence of throat tightness, a symptom that can quickly escalate into life-threatening airway obstruction. The study found that 75 per cent of tree nut allergy cases involved throat tightness.
Moreover, compared to other triggers of allergy symptoms, nut-induced anaphylaxis was among the most severe, with patients significantly more likely to require epinephrine administration in a hospital setting. Epinephrine—also known as adrenaline—is a life-saving treatment that can reverse anaphylaxis symptoms.
One of the study’s most striking findings was the strong association between alcohol consumption and severe nut-triggered anaphylaxis, reinforcing the need for individuals with nut allergies to be cautious when consuming alcoholic beverages. Alcohol also lowers the threshold for severe reactions, making early intervention with epinephrine even more critical.
Alcohol may exacerbate allergic reactions by worsening hypotension—low blood pressure—a critical aspect of anaphylaxis that can lead to shock. Because alcohol itself can cause a drop in blood pressure, it can intensify the already dangerous effects of anaphylaxis, raising the risk of cardiovascular collapse.
Additionally, some alcoholic drinks, particularly nut-flavoured liquors like Amaretto and Galliano, may contain traces of allergens—whether from natural ingredients or artificial flavourings—posing an additional risk to those with nut allergies.
“When you drink alcohol, just make sure you read what is labelled and what this alcohol drink has, because it could have some nut flavours, and you could have an anaphylactic reaction, and that is a life-threatening reaction,” Khalaf said in an interview with The Tribune, warning about the hidden dangers in some liquors.
Despite epinephrine being the first-line treatment for anaphylaxis, many patients fail to use it when needed. The study revealed that only 30 per cent of individuals experiencing tree nut-induced anaphylaxis used epinephrine before reaching the hospital, compared to over 50 per cent of peanut allergy sufferers.
This suggests that individuals with tree nut allergies may be less aware of the severity of their reactions or less likely to carry their auto-injectors. Increasing awareness and accessibility of epinephrine could be crucial in preventing fatalities.
“We need to make the EpiPen more accessible. We need to educate patients on the importance of using EpiPens and epinephrine if they experience an anaphylactic allergic reaction,” Khalaf emphasized.
With food allergies on the rise, proactive measures are necessary to reduce preventable deaths. Improved education, greater access to epinephrine, and stronger public regulations regarding food and beverage labelling can help improve outcomes for those living with severe allergies.
