Q. My son is allergic to peanuts, tree nuts and all seeds. I’m curious about the seed allergies: why is sesame viewed as a major allergen and declared in the ingredients of foods while sunflower seeds and oil are not? Also, since seeds are an issue, should we be worrying about mustard and mustard seed?
Dr. Watson: The 11 foods that the Canadian Food Inspection Agency has identified as priority allergens were declared such because they account for more than 90 per cent of severe adverse reactions related to food. They include peanuts, nuts, sesame seed, milk, egg, fish, shellfish, soy, wheat, sulphites and mustard.
My interpretation would be that sunflower seeds were not part of this group because they were responsible for fewer reactions. For your son, however, I realize that this is not relevant, and you must exercise the same precautions as with one of the priority allergens.
Mustard is, indeed, a seed. There have been several reviews of cross-reactivity in food allergy. Although there are a number of seed storage proteins and although mustard was recently added to Health Canada’s priority allergen list, cross-reaction among seeds is not common.
The most important question is: “Does your child currently eat mustard?”
If the answer is “no”, then there is no issue. If the answer is “yes”, the risk is extraordinarily low. I would suggest you talk to your allergist about any precautions to take if introducing mustard to his diet.
We welcome your question to Allergic Living’s Ask the Allergist. Thank you for understanding that the specialists aren’t able to answer every question received.
Dr. Wade Watson is a pediatric allergist and Professor of Pediatrics at Dalhousie University. He is also the head of the Division of Allergy at the IWK Health Centre in Halifax.