Co-sensitization to tree nuts observed in children with peanut sensitization and eczema: Study

A recent study conducted at Charite-Universitatsmedizin Berlin highlighted a significant link between peanut sensitization and co-sensitization to tree nuts in infants and toddlers with eczema. The study suggest that peanut-sensitized infants, particularly those under 2 years old, are at high risk for sensitization to tree nuts such as hazelnuts, walnuts, and cashews. The findings were published in the recent issue of Clinical and Translational Allergy journal.

The study evaluated 101 peanut-sensitized infants and toddlers, with a median age of 16 months, all of whom expressed specific IgE (sIgE) levels of at least 0.1 kU/l to peanuts. Among these participants, 98% had eczema which increased the risk of sensitization and the subsequent development of food allergies.

An overwhelming 96% of the participants demonstrated sIgE sensitization to at least one tree nut. Hazelnut was the most common allergen (94%), followed by walnut (87%) and cashew (84%). 80% of the children showed sIgE to all 3 tree nuts, while 27% were sensitized to the 2S albumins of all three nuts. The children sensitized to these albumins expressed higher sIgE levels than the children who were not sensitized.

5% of the infants had a 90% chance of reacting to hazelnut based on probability curves, while nearly 14% had the same likelihood for cashew. Overall, 16% had a high probability of reacting to either hazelnut or cashew. The study highlighted the elevated risks associated with peanut sensitization in infants, particularly for the ones already with eczema. These findings align with previous research by indicating that peanut allergy often increases the risk of tree nut allergies.

As a retrospective analysis, it lacked clinical confirmation of tree nut allergies through oral food challenges, which would have provided direct evidence of allergic reactions. The data spanned from 2007 to 2020, before the widespread adoption of guidelines recommending the early introduction of allergens to prevent food allergies.

Overall, the research highlights the importance of evaluating sIgE levels for tree nuts in peanut-sensitized infants, particularly those with eczema. Early detection and testing, such as oral food challenges, could help determine the clinical significance of sensitization and guide dietary recommendations to manage or prevent severe allergic reactions.

Source:

Meixner, L., Heller, S., Bluhme, F., Trendelenburg, V., Beyer, K., & Kalb, B. (2024). Infants and toddlers with sensitization to peanut are often co‐sensitized to tree nuts. In Clinical and Translational Allergy (Vol. 14, Issue 11). Wiley. https://doi.org/10.1002/clt2.70008