According to Food Allergy Research and Education (FARE), an estimated 3.9 million Americans have convincing symptoms of allergy to tree nuts. Tree nuts include hazelnuts, walnuts, pecans, cashews, pistachios, almonds, and brazil nuts but do not include peanuts, which are legumes, not nuts.
A study recently published in Clinical and Experimental Allergy sheds new light on tree nut allergies and how they are diagnosed.
The study looked at the prevalence of reported symptoms and allergic sensitization to tree nuts of 2,215 individuals at 24 years of age culled from the previous BAMSE population-based cohort study conducted by the Karolinska Institutet.
Using data from BAMSE — the Swedish abbreviation for Children, Allergy, Milieu, Stockholm, Epidemiology — they assessed early-life factors associated with the development of tree nut allergy.
The study found that developing atopic dermatitis (eczema), asthma, and egg allergy at an early age was associated with developing a tree nut allergy by adulthood.
They also drew a distinction between using allergen extracts vs allergen proteins in testing for tree nut allergy, preferring the protein over extracts.
The researchers stated:
Our study reveals that most extract-based tree nut-sensitized individuals do not have tree nut allergy but are solely birch pollen sensitized. The study also confirms that sIgE-ab to tree nut storage proteins are the best markers for specific tree nut allergy symptoms and storage protein sensitized individuals also showed several signs of more extensive allergic disease as compared to tree nut extract sensitized individuals, even in a population-based setting.
Said Jessica Bager, co-lead author:
This study increases the understanding of tree nut allergy in a general population, followed from infancy up to adulthood. For example, our study reveals that most extract‐based tree nut‐sensitized individuals do not have tree nut allergy and hence extract-based testing for tree nuts without a specific clinical suspicion should not be performed.
Have you been diagnosed with a tree nut allergy? It may be worthwhile discussing your diagnosis with your allergist to determine whether further testing is warranted.
- Facts and Statistics — FARE
- Prevalence and early-life risk factors for tree nut sensitization and allergy in young adults — Clinical & Experimental Allergy
- Study provides new insights on tree nut allergies — Medical Express