Q:

5/23/2013
I recently saw a toddler who developed peri-oral hives and lip swelling after eating a taiwan-made, Korean cereal bar. The bar contained: brown rice, lotus seed, barley, buckwheat, oat, peas, mung bean, red beans, black beans, soy and egg. Skin testing to the cereal bar was positive, but tests to barley, oat, tree nuts, sesame were negative. She eats rice, barley, buckwheat, oat, pea, and many types of legumes on a regular basis. The 2 ingredients that I could not confirm ongoing exposure to are mung bean and lotus seed. She regularly eats soy and other legumes, so my suspicion is with lotus seed. What can you tell me about possible lotus seed allergy? Does it cross react with any other seeds? Lotus seed is used in cultural foods consumed by this family, so it would be helpful if I could offer them additional guidance. Thank you.

A:

Thank you for your inquiry.

Unfortunately, I am not sure that I can be of help. I have never personally seen a reaction to lotus seed, and a search of the literature failed to reveal a single case. In addition, I could not find any in vitro tests for specific IgE to lotus seed or any article describing its allergens or potential cross-reactivity with other foods. The only thing that I can suggest to you to confirm lotus as the responsible allergen is to purchase the seeds and perform a prick-to-prick test with them.

However, because I could find nothing to help you, I am contacting Dr. Scott Sicherer, who has a special interest in pediatric food allergy, to see if there is knowledge with regard to your question that I could not find. Dr. Sicherer is a nationally recognized expert in food allergy and has published in cross-reactivity of food allergens. As soon as we have a response from Dr. Sicherer, we will forward it to you.

Thank you again for your inquiry.

Sincerely,
Phil Lieberman, M.D.

We received a response from Dr. Scott Sicherer. Thank you again for your inquiry and we hope this response is helpful to you.

Sincerely,
Phil Lieberman, M.D.

Response from Dr. Scott Sicherer:
After Google and Pubmed searches I have nothing really to add. It appears to be a very commonly used seed (sometimes called a nut) for food and medicinal uses. It is hard to imagine allergy would not be "possible" and one internet comment warns about possible allergy. I do not see work on allergen characterization (cross reactivity). I could not find it on Allergome. Obviously, allergy to this food is not "common" unless reports are buried in non-English sources. There are case reports of all sorts of allergic reactions to various fruits, seeds, etc., that are not in our western mainstream diet and so the doctor may want to continue her evaluation and write a case report.

Scott H. Sicherer, MD

AAAAI - American Academy of Allergy Asthma & Immunology