Findings from a new study have questioned the clinical relevance of co-allergy and suggest patients with a history of a single tree nut allergy may not need to avoid all other nuts until such allergies are confirmed.
The study, published in the Annals of Allergy, Asthma and Immunology , found that among people allergic to one nut who have a positive test to other tree nuts, more than half passed an oral food challenge to other tree nuts without reaction.
“Previous studies suggested people with a tree nut allergy, as well as those with a peanut allergy, were at risk of being allergic to multiple tree nuts,” said Matthew Greenhawt, chair of the American College of Allergy, Asthma & Immunology’s Food Allergy Committee and study co-author. “We found even a large-sized skin test or elevated blood allergy test is not enough by itself to accurately diagnose a tree nut allergy if the person has never eaten that nut. Tree nut allergy should only be diagnosed if there is both a positive test and a history of developing symptoms after eating that tree nut.”
The authors said additional studies are needed to help guide clinical decision-making in this area.