A new study published in the journal Allergy highlights shifting trends in severe allergic reactions to tree nuts. Specifically, the research found that almonds are appearing more often as a trigger of anaphylaxis in adults, while cashew nuts have rapidly risen as a leading cause of tree nut-induced anaphylaxis in children.
Although the study didn’t specifically include people with systemic mastocytosis (SM), its insights into how nut allergies are changing in the general population highlights their potential risk for people with SM, who already face an elevated risk of anaphylaxis.
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Researchers analyzed data from nearly 6,000 food-related reactions recorded in the European Anaphylaxis Registry between 2007 and 2024, and found 1,083 confirmed cases of tree nut–induced anaphylaxis (845 in children and 238 in adults). In adults, hazelnut and walnut were common causes of reactions, but almond — which has traditionally been seen as low-risk — surfaced more frequently than expected, accounting for 35 cases.
In children, cashew was the top culprit, accounting for about one-third of pediatric cases, followed by hazelnut and walnut. The researchers note that cashews have become more prevalent in different foods in recent years, including snacks, in cooked meals and as a vegan substitute for animal products, which likely contributed to increased reaction rates.
The study authors also noted that cofactors, including exercise or medications, were present in about half of adult cases and in roughly one in six pediatric cases.
Alarmingly, epinephrine use during reactions was low across both groups: Just 3% of adults and 13% of children received it from bystanders, with professional use reported in only about 40% of cases.
The authors call for greater public and clinical awareness of cashew and almond allergy trends, emphasizing that changing dietary habits, such as increased use of nuts in plant-based foods, may contribute to rising exposures.
For individuals with SM, these results underline the need for ongoing vigilance around nut ingredients and the importance of having ready access to an epinephrine auto-injector and a clear emergency plan.
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