HomeAsk the allergist – October 2023

Ask the allergist – October 2023

October 6, 2023

Ask the allergist is a regular feature in our newsletters where Canadian allergists answer your questions! Please note: The allergists featured in this series answer questions on general topics, please talk to your doctor if you have questions about your own health or the health of your child. 

This month Dr. Julia Upton answers questions about allergy to crustaceans (e.g., lobster, shrimp, crab). 

Is it safe to eat imitation crab if you’re allergic to crustaceans? 

Imitation crab is typically made from a finned fish called pollock. However, some manufacturers add real crab and/or other shellfish (crustaceans and molluscs) for flavour, and it’s important to read the list of ingredients. Overall, the risk of allergic reaction is likely quite low but there is some risk.  

I’ve heard that you have to be careful with glucosamine supplements if you’re allergic to crustaceans. Why is that? 

These supplements are often made from the shells of various crustaceans. However, there is expected to be very little crustacean protein in them, and it is the protein which triggers an allergic reaction. There have been small studies that suggest people with crustacean allergy do not react to glucosamine supplements. On the other hand, there have been reports of allergic reactions to glucosamine supplements in the past. Overall, the risk of a reaction is likely to be extremely low, but not zero. 

For both of these questions, the safest option is to avoid, but this may be overly cautious. Whether you try these types of foods or supplements may be influenced by your past severity of reaction, whether you have asthma, your personal risk tolerance, and ensuring you have emergency treatment (i.e., epinephrine) available if there was a significant exposure to crustacean.  

A discussion with your allergist for thoughts on your personal risk and reflection on your own risk tolerance may help guide what living confidently with food allergy looks like for you. 

Dr. Julia Upton
Dr. Julia Upton

Dr. Julia Upton is on staff at the Hospital for Sick Children in the Immunology and Allergy Department; and an Associate Professor in the Department of Paediatrics at the University of Toronto. She is the past Section Chair of the Anaphylaxis and Food Allergy Section of the Canadian Society of Allergy and Clinical Immunology. Dr. Upton is also a member of our Healthcare Advisory Board.  

Please note: Dr. Upton is answering as an individual allergist and her answers do not constitute an official position of her affiliated organizations. Her responses are for informational purposes only and do not constitute specific medical advice, recommendations, diagnosis, or treatment. Please talk to your doctor about any concerns or questions you may have regarding your own health or the health of your child.  

Do you have a food allergy-related question you’d like to ask an allergist in the months to come? If so, send it along to us at info@foodallergycanada.ca

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