Q:

6/5/2012
Recently saw an 18 month old child with multiple possible food intolerances. His skin testing was negative to all foods tested but his mother has noticed sensitivities to corn, milk and soy. Reactions generally include skin rashes and abdominal distress. She is interested in keeping corn in any form out of his body including topically. He has had difficulty recently when his PCP ordered eye drops with corn derivatives which did worsen his eye symptoms. Is there any information about complete corn avoidance including medications- both topical and oral? When investigating some medications for his abdominal symptoms, that class of medications did include several possible corn products. Thank you for your time.

A:
Thank you for your inquiry.

Unfortunately, there is no definitive information located in one place which lists all products containing corn. There are lay websites which deal to some extent with this issue. For your information, I have copied a link below to one of these sites.

http://allergies.about.com/od/foodallergies/a/cornallergy.htm

Other than using such a lay website and reading labels, there is no other way to deal with this issue.

Also, the issue is complex because some products, such as corn oils, are labeled as having corn, but actually do not contain corn allergen. To help you understand this, I have copied below a recent response to a question submitted to our website regarding avoidance of corn allergens.

In summary, use of a lay website and reading labels is all that one can do in regards to your patient.

Thank you again for your inquiry and we hope this response is helpful to you.

Inquiry and Response to Ask the Expert website:
32 year-old allergic to wheat and corn requiring enteral feeding

Question:
5/18/2012
I have a 32 yo patient allergic to wheat and corn. Are there any corn product derivatives allowed? I've been told that corn syrup solids do not contain the corn protein, so they are safe. However, I can't find any information to back this up. I appreciate any help in this matter. This pt needs to be enterally fed, so this is becoming a real challenge to find a product for him! Thank you!

Answer:
Thank you for your inquiry.

I am going to ask Dr. Scott Sicherer, an internationally known expert in food allergy, to respond to your inquiry. As soon as I hear from Dr. Sicherer, I will forward his response 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:
I deferred the query to our dietitian, who gave the following overview. Her knowledge base on this apparently derives from casual discussions with Steve Taylor, who perhaps is a better person to address the question, but to save some time/effort I paraphrase Marion's response below and have CC'd Steve. We are not aware of specific studies to "back this up".

From a clinical perspective, we use formulas that contain corn syrup and corn syrup solids without difficulty for patients who are allergic to corn. We therefore do not restrict a formula with these ingredients for a patient with corn allergy. However, we are not aware of specific allergenicity studies on these ingredients.

Corn starch is an ingredient that may have a very trace amount of corn protein (which probably has no clinical relevance for most people with a corn allergy). Baking powder contains corn starch, but the amount of baking powder ever used in a product is so small that the amount of corn starch would be even smaller, and, therefore, the amount of corn protein would be extremely miniscule- almost surely undetectable in a serving of such a product.

Corn starch (already with only very trace protein) is the starting material for corn syrup. The final products of corn syrup, glucose syrup, dextrose (granular) or high fructose corn syrup should have undetectable corn protein.

Scott H. Sicherer, MD
Professor of Pediatrics
Jaffe Food Allergy Institute
Mount Sinai School of Medicine
New York, NY

We received additional information from Dr. Steven Taylor regarding your inquiry.

Thank you again.

Sincerely,
Phil Lieberman, M.D.

Response from Steven Taylor, PhD.:
Marion's answer is quite accurate. Corn syrup (also known as glucose syrup), corn syrup solids, glucose, dextrose, maltodextrin, corn oil, and high fructose corn syrup (note I have added a few ingredients) have no detectable corn protein residues and should be quite safe for someone with IgE-mediated allergy to corn. Corn starch can contain up to 40 ppm (ug/g) of corn protein but that is a small amount in most applications of corn starch and is probably tolerated by most individuals with corn allergy.

This information is well documented when suppliers of these ingredients do compositional analysis of these products. However, it is not well documented in published literature.

Of course, I might add that a fair number of individuals believe that they have corn allergy based upon a number of self-help "medical" books sold at health and natural foods stores. This theory was more popular 20 years ago then it is today but the food industry still encounters individuals who firmly believe that they are allergic to ingredients like high-fructose corn syrup. So, whenever I get a question such as the original one posed, I always wonder if I am dealing with someone who has a legitimate diagnosis or one of the self-diagnosed cases. Of course, there is no way to know. But that is why I always try to refer to IgE-mediated corn allergy because we can be pretty definitive that there are no documented cases of IgE-mediated corn allergy attributable to corn syrup et al.

Steve Taylor, FARRP

Sincerely,
Phil Lieberman, M.D.
AAAAI - American Academy of Allergy Asthma & Immunology