30. July 2019
Walnuts can trigger severe allergy symptoms

Allergies are caused by antibodies against specific storage proteins in walnuts. Children are more susceptible than adults and develop more severe reactions. This was the conclusion of a study by the University of Zurich, Switzerland.

Children under 14 years of age form specific immunoglobulin E (IgE) antibodies against walnut storage proteins. These high IgE levels lead to symptoms that affect the entire body, which are also called systemic symptoms.


IgE levels are lower if the onset of the allergy occurs after age 14. For this reason, the allergy symptoms were usually less severe in patients over 14 years than in the younger patients in the study. Nearly 40 per cent of those over 14 experienced only mild symptoms.


Barbara Ballmer-Weber from the University Hospital of Zurich, Switzerland, came to this conclusion. She studied 91 children and adults with walnut allergy in cooperation with the Paul Ehrlich Institute (PEI), a German research institution.


“Based on in-vitro investigations, the current findings can help to evaluate the severity of walnut allergy more precisely than in the past and to develop targeted approaches for specific immunotherapy,” says Professor Stefan Vieths, vice president of the PEI, explaining the significance of the study.



Press Release: Speicherproteine der Walnuss lösen schwere Lebensmittelallergien bei Kindern aus. Paul-Ehrlich-Institut, Februar 2019.


Original Study: Ballmer-Weber BK et al. Allergen recognition patterns in walnut allergy are age dependent and correlate with the severity of allergic reactions. J Allergy Clin Immunol Pract. 2019;7(5):1560-7.