Recent research reveals something surprising: the strength of an allergic reaction to food isn’t necessarily connected to how much of the allergen someone consumes. This means that the amount of allergen consumed can be an unpredictable indicator of how severe an allergy reaction might be.1
A new study spearheaded by Alexandre Piletta-Zanin at the Pediatric Allergy Unit in Geneva, Switzerland, underlines something many allergy sufferers want to know: what risks they might face in everyday situations, especially with processed foods and when dining out. This is crucial because standardized food challenges in clinical settings can vary a lot from real-life scenarios.2
Piletta-Zanin and his team set out to understand the connection between the type and amount of allergenic food, the food consumed, and how severe the symptoms were when people had accidental reactions. They pulled data from emergency departments, schools, and allergy clinics following reported allergic reactions to food.
Background and Study Design
To gather data, the research team attracted participants from various sources in Geneva between December 2020 and December 2021. While they aimed for a thorough recruitment process, it wasn’t entirely systematic. They included participants of all ages who experienced immediate allergic reactions to food, defined as having symptoms within two hours of eating a suspected allergenic food.
They skipped over anyone with signs pointing to food intolerance, those with delayed reactions, or reactions that fell outside the recruitment timeline. They collected detailed medical histories from participants and also gathered samples of the foods that triggered reactions.
Both retrospective and prospective allergy assessments were performed on participants, along with analysis of the food samples collected to check for the amount of allergen present.
Key Findings
By the end of the recruitment period, the team had reached out to 263 people, enrolling 147 who met the study criteria. They collected 115 food samples linked to the reported reactions. Notably, none of the participants experienced more than one reaction during the study.
The team’s findings highlighted tree nuts as the most frequent culprits, leading to 43 reactions, followed by cow milk (20), shellfish or fish (13), peanuts (8), and eggs (6). Chocolate popped up as the most commonly suspected, causing 16 reactions, mostly linked to nuts and milk.
They found that many affected individuals were children, and most reactions resulted from eating prepackaged foods. In seven cases, the products had either precautionary allergen labeling or no labeling at all. What’s more, the severity of reactions varied widely, showing that the amount of allergen consumed didn’t consistently predict how severe the allergic reaction would be.
In fact, the researchers found no significant difference in the allergen amounts between those who had mild reactions and those who experienced severe ones. “In conclusion, we found that the severity of the reaction did not correlate with the consumed amount of the allergen,” they stated. This is a vital takeaway: some people might react strongly to tiny amounts, while others could tolerate larger quantities without any serious issues. This highlights the importance for individuals to be well-informed about their specific allergic reactions.1
References
- Piletta-Zanin, A., et al. (2024), “The Severity of Allergic Reactions in a Real-World Environment Is Independent of the Eliciting Amounts of Foods.” Allergy. https://doi.org/10.1111/all.16413.
- N. Patel, et al., “Using Data From Food Challenges to Inform Management of Consumers With Food Allergy: A Systematic Review With Individual Participant Data Meta-Analysis,” Journal of Allergy and Clinical Immunology 147, no. 6 (2021): 2249–2262.
