Don’t Panic: A Beginners’ Guide to Corn Allergy

So you’re allergic to corn.

First: Are you SURE you are allergic to corn? People often forge ahead with this as an assumption and in some cases, it might be best to question it, at least for a minute. As you will realize as you read the rest of this post, avoiding corn is not as simple as cutting a few foods from your diet. Corn is not only a food, it is a food additive, preservative, disinfectant, lubricant, emulsifier, anti-caking agent, and more. Not everyone has to avoid everything derived from corn, but for some reason more people have to avoid more derivatives than you’d ever expect.

If you’ve had an adverse reaction to a food, you should definitely avoid that food in the future. But if the food had many ingredients besides corn, it might be worth taking some time to think critically about whether the corn in the food was the problem or something else.

So before you start turning your life upside down: What gave you your diagnosis? Was it a scratch test? Those have false positives. Was it a blood test? Those don’t usually have false positives, but it could happen. Did you do a food challenge? What was the food you challenged? Any chance it was a possible allergen contaminant in the food other than corn?

Okay, so you’re SURE it’s corn that you’re allergic to. Now what?

The steps for dealing with a corn allergy are about the same no matter how severe your reactions are. But if you are having severe reactions, you need to follow sort of an accelerated schedule and get yourself out of crisis ASAP.

Symptoms of severe reactions include:

  • tight, hoarse, trouble breathing/
    swallowing
  • shortness of breath, wheezing, repetitive
    cough
  • Significant swelling of the tongue, lips
  • becoming pale, blue, faint, having a weak pulse, being dizzy
  • rash/hives over more than 25% of the body
  • widespread redness/flushing
  • loss of consciousness (including feelings of excessive sleepiness that you just can’t fight- getting to lay down before you pass out still counts as passing out!)
  • loss of motor coordination
  • extreme swelling of the eyes, lips, or anywhere else in the body
  • prolonged and or painful diarrhea/intestinal cramping
  • prolonged vomiting
  •  Feeling something bad is about to
    happen, anxiety, confusion

Read more about the signs of anaphylaxis here on the Food Allergy and Anaphylaxis Network.  In particular, please take a look at, and carry with you, this simple handout on how to recognize and treat anaphylaxis. Here is another overview of the effects of anaphylaxis on the body. If you are having these kinds of reactions, you need to make drastic changes right NOW, get as corn free as possible to begin. Then maybe you can see how much you can tolerate adding in from the “corn lite” options. People with less severe reactions can sort of take their time instead of diving in head first.

Who This Guide Is For

This guide is written for people who are reacting a lot or reacting severely, because that’s the situation I came from, but I think it can contain good advice for others.

Even if you aren’t currently in crisis, I don’t suggest that you start out by assuming that you aren’t very sensitive and don’t need to make many changes. Rather, I strongly suggest you aim for going completely corn free within 6 months, and *then* see how well you do with derivatives and traces. The reason I suggest this is that there are a number of symptoms people wouldn’t typically associate with an allergy or intolerance such as joint pain, mild GI distress, acid reflux, “random” mild rashes or itching, eye pain, fatigue, bouts of sleepiness, blood sugar highs and lows, and eczema, that can disappear with the elimination of corn, but that you wouldn’t realize are a reaction until you eliminate the offending food for a while and then reintroduce. All of these symptoms are indications of inflammation that are doing long term damage to your body, so it is in your best interest to eliminate those sources of inflammation so that you can heal.

Learn the Basics

The following article is a really good overview on the spectrum of allergies and sensitivities. Please read it right away to give yourself a good grounding in the basics before beginning your corn free journey: Inflammation – Allergies and Sensitivities on WomenToWomen.

Get Support

Find a community of people who have already done this. I suggest the Corn Allergy and Intolerance group on Facebook because it saved my life literally in 2012, but it’s also grown quite a lot since I joined, and more members means more posts from other new people.  I strongly believe that communicating with other patients can help you learn more about your own situation- there is no way I would have made the progress I have with either my food sensitivities or my other conditions without learning from others what did and didn’t work for them.  But keep in mind: no matter where you get support, that there is no shortcut for studying, learning, and using your best judgement.  If someone tells you that something is corn free, and it sounds to good to be true, probably err on the side of caution.

Stay Safe

  1. Figure out how to safely treat reactions.
  2. If you have the kind of severe reactions listed above, get a prescription for an EpiPen. If you have reactions that aren’t necessarily severe but are definitely a “true allergy” meaning hives, rashes, asthma, and other IgE symptoms, you may want to consider getting an EpiPen just in case. A bit more on “true allergies” vs intolerances. If your usual doctor won’t give you one, try the walk-in clinic. If they won’t give you one, skip directly to the “Get Your Doctor On Board” step and find someone who will write you a prescription. Learn when to use your epipen. The EpiPen 2-pak comes with a “training” pen and instructions on how to use. Read up on it before you need them and train at least one family member on how to use it as well.
  3. Read this emergency medicine info. Bookmark the mobile site and use the information to prepare your own ER docs.
  4. Don’t assume that if you do not have a true “allergy”, you cannot have a severe or life threatening situation as a result of your corn sensitivity: there have been some rare incidences of IgG, the immunoglobulin that causes “food intolerances”, causing anaphylaxis:  https://www.ncbi.nlm.nih.gov/pubmed/21029722/
  5. It is possible for food to do lasting or even immediately life-threatening harm without allergies being involved.  The following are not corn, but illustrate some ways that food can harm you other than allergy:
    1. Sulfite sensitivity is not mediated by IgE but can be deadly.
    2. Celiac disease is an autoimmune response to food and can do lifelong irreparable damage to your body.
    3. G6PD deficiency causes red blood cells to be destroyed in the presence of certain food or meds. This can be deadly and in some extreme cases people have died from airborne exposure to a trigger before they could be given blood transfusions.

Clean Up Your Food

Simplify your food choices. How far you go with this depends on how sick you are. If you feel relatively healthy, you may just need to start with the Corn Free Food & Product List, read through a few beginners’ links, and slowly eliminate suspect items from your pantry.

If you’re reacting a lot or you have been at it for a while and still feel ill but can’t quit figure out why, you may need to just quit eating anything with a label. Yes, this will be boring, but it won’t be forever.

Think of it this way: you need to find out what you are reacting to. If your typical dinner contains 3 or 4 different items which each have 5+ ingredients, and are then cooked in various types of oils, topped with spices and salt, on top of a bed of grains or a slice of bread, how will you know which item you are reacting to? Was it the salt, the cooking oil, an ingredient in the one of the foods? Was it the grain? How about the vegetables? All of these items *can* be corny, depending on how they were grown/packaged/processed, and additionally you can have an adverse reaction to any food at any time, even if you tested negative on an allergy test for it. So while you are still getting a baseline, you need to eat very few foods, prepared very simply.

Start with a list of single, whole foods you think are completely safe for you. Stay away from anything in a package other than salt and cooking oil. Searching for Paleo Recipe blogs, or searching Pinterest for Paleo recipes can provide some inspiration for meals.

Question everything. Actually, even be suspicious of your salt and cooking oil. I have had some MAJOR olive oil fails and actually still don’t have a safe olive oil or even a safe pressed cooking oil at all. Just butter and the fat I render from my safe custom process meat. Ask in your support groups what is working for others BUT DON’T ASSUME THOSE WILL WORK FOR YOU. If you find you are reacting to everything you eat, that’s a good sign that your problem is what you’re cooking it in. Either spices, cooking oil, or pan. (Cast iron and pitted teflon can really hang on to allergens previously cooked in them, and there are many reported reactions to the teflon itself as well- I haven’t even tried it since discovering my allergy.) Consider braising or boiling your food for a time to eliminate even that factor. Boring, yeah, but safety first. Skip other spices for now until you have a clearer picture of what is safe for you.

For salt, many people do well with either Penzey’s kosher flake salt, or himalayan salt chunks in a grinder. I can’t do any salts that have been pre-ground even to the point of small chunks, and have to get the big himalayan salt blocks meant for salt plate cooking. I rinse them off under safe water for several minutes until the outside layer has been washed away, then let them air dry. Once dry I use an oversized stoneware mortar and pestle meant for making avocado, and stick a corner of the plate in the mortar and whack at it with the pestle until a chunk comes off. I then whack the cunks until they are gravel sized or smaller, and then use my Blendtec high-powered blender (comparable to Vitamix) to grind them up the rest of the way. DO NOT PUT LARGE CHUNKS OF SALT IN YOUR VITAMIX OR BLENDTEC.  They are literally rocks and will punch a hole through the side of the jar. I learned this from experience and had to buy a new blender jar. I do not know if you can do this with a “regular” blender. I think you need a very high powered one. If you do not have a high powered blender and you need to use this method for salt, I would recommend using a manual salt grinder instead.

For cooking oil, that can be pretty difficult for some people. The safest cooking oil I know of is the Jovial olive oil which you can buy online from Jovial. There are other oils that are working for people such as California Olive Ranch olive oil, and Nutiva organic coconut oil, but Jovial is the most universally tolerated. I cannot do Jovial and until I found some safe-for-me grassfed butter I didn’t have any cooking oils at all and had to braise, boil, or bake everything.

Get a feel for what “clean food” looks like. When choosing foods, stay away from items that are commonly waxed such as apples, oranges, cucumbers, and anything else that looks shiny to you. Prefer dirty produce over super clean, as citric acid or other preservatives or surfectants could have been added to the wash water. Prefer things that are loose rather than packaged- the packaging could be corny, and more handling/processing is more room for contamination. Stay away from root vegetables that “usually” sprout  such as potatoes and sweet potatoes that  you haven’t personally seen sprout,  as they may have been treated with a corny “bud inhibitor.”  There are more ways for whole foods to be corny than what I’ve mentioned, so if you observe that you react, do some research using the links I’ve provided into how the item could be corny. It *could* be a new food allergy, but it’s corn so often that it’s important to look into it before taking that food item out of your diet forever.

Keep eliminating and switching foods until you are reaction-free. For the *extremely* reactive folks, sometimes this can mean going down to a list of 20 or fewer safe foods. Or 5 or fewer, or 2 or fewer.  I’m not sure, but I think this happens most often when folks are both very sensitive and multiply allergic and/or have other autoimmune issues going on. And when you get down to that kind of sensitivity and immune disaster, *which* foods are safe seems to vary drastically between people as well. For me it was eggs and pears. I doubt this would work for ANYONE else, as the eggs were corn fed and the pears are a common oral allergy syndrome trigger for people. But that’s what it came down to for me as far as what I could tolerate without my throat closing up. I now have far more foods than those two items, but I had to just give my body a rest for a while and get a baseline before I could start building back up.

As I mentioned in the beginning of this post, if you aren’t highly reactive, you have some leeway to go about this elimination at your own pace. But if it were me, I wouldn’t put it off for too long. The lengthy explanation of why is a topic for another post. Just trust me that you probably aren’t doing yourself any favors by delaying healing.

Keep a Food Journal

This is crucial- even with a simplified list of foods, often the only way to see patterns in reactions is by looking back over what you ate for several days or a week or more. There are lots of ways to do this, and you’ll have to find what works for you. Maybe it’s a Google Doc you have linked in your bookmarks bar. Maybe it’s a tiny notebook in your pocket. Maybe it’s a doc on your phone that you add to. Maybe it’s you taking a picture of every meal and Instagramming it with comments. Doesn’t matter, just do it. Write down what you ate including ingredients, and the time, and how you were feeling. Then also make sure to log any reactions or weird occurrences and the time, even if they were well away from a meal time.

Some great advice on how to keep a food journal on News for Corn Avoiders.

Find Local Resources

Included in the “Files” section of the Facebook group is a list of approved regional corn allergy groups. These groups are moderated by knowledgeable members of the group and are intended as a place to share local resources that wouldn’t be useful to anyone who doesn’t live in the area, and will be a good place for you to ask questions like, “Where the heck can I get eggs from chickens that aren’t fed corn?” or to share information like, “The popcorn cart near the Pacific Science Center in Seattle emits such a pungent and far-reaching corn aroma that I had an asthma attack and almost passed out when 50 feet away from it.” (Can you tell this literally happened to me?)

To find safer vegetables than what you may be able to access in the grocery store, check localharvest.org for local farmers’ markets or CSAs. Note that organic does NOT mean corn free. You may need to ask some questions of the folks growing the veggies you buy.

Here are the considerations I need to attend to when looking for safe food for myself. Not everyone needs to go this far, but I figure knowing what is possible can only help you.

  • Any product that is applied to the part of the food you eat is likely to be a problem. Even certified organic sprays and fertilizers can contain corn derivatives.
  • When you ask about what is used for pest control or fertilizers, keep in mind that the answer will be different per crop for a single farm, and different between farms for the same crop.  Don’t assume because one item is safe, it’s all safe.
  • Realize that peoples’ education and philosophy of what is “safe” and “healthy” can vary widely, and also that “safe for you” doesn’t mean “safe for everyone.” Consider softening your questions to avoid making it sound like you’re suspicious that the farmer is doing something “unsafe” or “unsavory” when you ask about sprays. Maybe instead of asking about sprays, ask about “what they do for pest control.” Be interested in the agricultural challenges they face. Hopefully you won’t have to fake it.
  • Try to ask your questions at non-busy times. Show up very early or late, or maybe arrange for a farm visit so that you aren’t competing with other customers for attention.
  • Be prepared to ask the same question different ways several times. Sometimes you will get a market booth worker who doesn’t work the farm.  Sometimes they’ll be super busy and just not thinking through the question/misremembering.  Sometimes they’ll be 6 months pregnant and not know up from down. (This happened with one of my dear friends/farmers.)
  • Be aware that what is done for a crop can even change mid-season. For example, in my area cabbage worms are a BIG problem in the hot weather, and will completely wipe out a crop if they are not addressed aggressively. Even beyond-organic farmers will use a Pyrethrum spray on their brassicas in the hot weather, but not in cool weather. This spray may not be a harmful chemical, but the inactive ingredients invariably contain corn.
  • If you are buying from a farmers’ market booth instead of direct from the farm you will also want to know what the veggies were transported over in and whether they shared storage or truck bed with corn. I honestly won’t even buy from farms who grow corn because the chance for cross contamination is too much and I’m so reactive. But I have lots of choices for no-spray farms, so I can do that. Others may not be so lucky.

Concerned about cost? If you have SNAP/EBT benefits, there are many farmer’s markets that accept EBT cards. Here is a list of Farmer’s Markets that accept them. (This is the official Food and Nutrition Service document, and is a Microsoft  Word document. If you don’t have Word, I will try to keep this Google Doc version updated.)

For meat, dairy, and egg resources, check eatwild.com for farms in your area that might sell stuff that is safe for you. But keep in mind that meat can be kind of an advanced topic for the highly sensitive,  and so can dairy, especially cheese. so you may wish to just avoid animal products for a time while you get the rest of your diet figured out. But hey, you may not need to go the whole 9 yards with custom meat processing. Maybe all you need to do is start going to a real butcher instead of getting meat from the grocery store that has been treated with corny food dyes to keep it looking fresh and then triple-rinsed in corny disinfectants.

Get accustomed to the idea of local, seasonal eating. For the very sensitive, the only way to get safe food is to be able to confirm with the person that grew it that nothing was ever sprayed on it (even organic pesticides and antifungals are in corn-based solvents) and that the foods weren’t stored, transported, or packaged with something that contaminates them. Even if grocery store produce works fine for you right now, it’s good to find out ahead of time what local resources you have. Use the sites above to find out what’s available to you. Get hooked up with community supported agriculture programs, and find farmers’ markets. Show up, talk to some folks, get a feel for it. Become a part of the community. It’s rewarding in and of itself and will pay off later if you ever end up in a situation where you are having trouble sourcing safe food.

Cut Down on Trace Exposure

  • Medication: Figure out the rest of your medication, especially daily stuff. Use the corn allergens list to compare to the inactive ingredients in your medications. Sometimes it’s a little hard to find out the inactive ingredients of prescription meds, so I have a little write up of how to do that here. You may need to have some of your meds custom-made for you with ingredients you tolerate. There are pharmacies called compounding pharmacies that can do this for you. Some advice on how to get medication compounded safely and successfully here.
  • Water: Yeah, really. People react to water. I do. Filtration systems can introduce corn traces, chemicals can be added to buffer the PH that are corn based, corn based disinfectants can be used, and water bottles can be made out of corn plastic.  Most people do well with either Crystal Geyser bottled water or the Berkey ceramic gravity filter with the additional fluoride filters. Here is everything else I know about safe water. 
  • Cookware: Do you have cast iron? It’s probably holding old allergens in. How about teflon? Many people react to it, and if it’s pitted will hold in allergens. Maybe buy just one new stainless, glass, or enamel-coated pan right now and make sure it always says pristinely allergen free. Make sure it’s something that can be completely cleaned of any allergens.
  • Body products, laundry detergent, and dish soap:: Many people are skin reactive to at least *very* corny items. In fact, some people are *more* skin reactive than they are food reactive! But even if you only react to ingested corn, you will find that you ingest way more of your personal care products than you’d ever realized: touching your food and lips with your hands, getting your hair in your mouth, etc.  Use the corn allergens list to check ingredients, reccomendations from the group or forum, and the Corn Free Food & Products List as a reference for some things to try.

Get Your Doctor On Board

Or find a doctor who will get on board. People tend to want to go to an allergist/immunologist right away. I think going to a specialist is a great plan, but you have to find the RIGHT specialist, and the good ones are often booked up. You need someone to be a primary care/home base for you right NOW. So go with your current primary doc if you can get them on board to understand your allergy, or find a new one if you can’t. You need someone who will listen to you and believe you about your own body, who will not try to encourage you to eat corn derivatives because “all the protein has been processed out”, who will not try to get you to take medication that has just “a little bit” of corn in it, and who will write you compounding prescriptions.

I’ve gone to see several new doctors in the last year, and I think I’ve finally got my process streamlined. I typed up the following documents to bring along:

  1. A one-to-two-page bullet-point list detailing my health history. It focuses almost exclusively on my allergy history at this time, stretching back to childhood, but includes major health events like scarlet fever and a tonsilectomy.
  2. Pictures of my more dramatic reactions.
  3. A bullet-point list of current medications and supplements, including dosage and frequency.
  4. My current safe food list.
  5. A bullet-point list of health goals.
  6. My ER Safety protocol
  7. A copy of the corn allergens list.

When shopping for a PCP, instead of attempting to go over these documents with the doctor in the appointment, I hand them to the receptionist before I go in. If the doc is worth anything, they will read it before they come in and come in with focused questions. If they don’t walk in compassionate and prepared, you should probably just leave and find a new doctor.

When shopping for specialists, I approach it a bit differently.  I bring in an abridged version of my “medical packet” that is tailored to what I think is relevant, and I present it to them in the appointment without trying to get them to study ahead. I already know they won’t. This approach does mean that sometimes I get flustered and derailed, but if they’re a derailing type and I am not able to redirect them, that’s important information for me to know and I need to use that info to decide if they should continue treating me.

Become an Expert on Hidden Corn

Start figuring out about where corn hides. It’s overwhelming, but you NEED to become an expert to remain safe.

With that last link, I don’t suggest reading the whole thing end to end. You’ll end up hiding under the bed with a tinfoil hat on. Just search it when you are wondering, “How could there be corn in this item?” Get your information in manageable chunks.

Get Your Workplace on Board.

It’s important to proceed carefully here and not ask for accommodations until you’re sure you know what you need. If you do not know that you are airborne reactive, don’t go insisting on a corn-free floor at your work until you do know. On the other hand you need to make sure that you stay safe, so this can be a difficult line to walk. Another thing that I don’t really have the answer for is that sensitivity levels and reactivity changes. Things that are okay when you ask for accommodations may change, and it’s hard to say what effect it will have changing the requests when you’ve already gotten people used to one way of doing things. Again, it’s very hard to walk the line between your safety and what is a “reasonable accommodation.” Maybe just start with, “I have this allergy. I know I have dangerous reactions. I do not yet know exactly what accommodations I will need, but for right now I need this short list of things.”

If you have severe reactions and may ever have to miss work as a result, or have already had to, learn about your company’s policies on long and short term leave sooner rather than later. If you’re in and out of the ER or having to see a lot of specialist doctors, consider putting in for something like “intermittent family & medical leave,” if it’s available at your workplace. This essentially gives you the *option* to take unpaid hours off without risking losing your job. Essentially, you want protections in place BEFORE a boss has a chance to penalize you for missing too much work.  I renew my intermittent FMLA every 6 months with a letter from my doctor explaining that I have multiple chronic conditions, and that I may need to miss between 4 and 8 hours at a time of work due to either flares of my conditions, or treatment or diagnosis related to them. I have up to 3 days per month available of this. I have used it rarely, but it is there should I need it, and I can take it in addition to my vacation and sick hours.

Don’t Panic

So there’s your to do list. It’s a lot. But just take it one thing at a time. You CAN do this. Get support through the groups and your loved ones and remember to breathe.

Don’t Stock Up Right Away

It’s easy to want to buy things in bulk to save money and to feel secure that you will have enough to eat, but at least in the beginning stages, try to buy only as much as you need and only replace things as you need to. This allergy is expensive and that money adds up. Additionally, your tolerances will shift and you may end up with a case worth of something that you react to.

Instead of buying an entire set of new pans because your old ones are corned, consider buying just one good pot and one good pan and using those for a bit. Instead of buying an entire case of canned beans you think you are fine with, buy just a couple at a time until you know you are doing very very well with them. On the other hand, if it is a seasonal item like fresh, unsprayed, unwaxed apples or unsprayed peaches (VERY hard to find), get just enough to trial, then if you tolerate buy a huge quantity and preserve in the freezer or by canning.

Choose your battles and spend your money wisely.

Keep Thinking Critically

This is just good life advice, honestly. But it’s especially good life advice if you are doing all of the above and are still sick. You may be overlooking something or taking something for granted, or you may even be on the wrong track entirely.

Unfortunately I see a pattern with highly reactive folks, myself included, where they get sicker and sicker and lose almost all of their foods, before they finally figure out the ONE thing that is getting them. And sometimes it is a lot of stages of finding The Thing and eliminating it, and finding something else was still bugging you.

And sometimes it’s more than corn, or in some cases it wasn’t corn at all. I have totally seen some people become extremely sick on top of being allergic to corn, or actually just be sick and not even allergic to corn in the first place, but their reactions are so weird that they think it’s food when it isn’t really. It happens. I don’t EVER want to question someone’s expertise on their own body and reactions, because having it done to me has been very hurtful. I’m just saying that lots of things are possible, and you may have more or different problems than you initially thought.

Just keep your eyes open, get support from other allergy people, and as much as possible journal and write down EVERYTHING to help you think critically about what is going on.

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7 thoughts on “Don’t Panic: A Beginners’ Guide to Corn Allergy

  1. This is so thorough! When I was first diagnosed with celiac disease, I actually felt worse initially after going gluten-free, and I wondered if it might be an issue with corn, since I’d started eating more of it. I’m feeling better now (although not totally), so I’m less concerned that I might have a corn allergy or intolerance, but just for the sake of anyone in my prior nervous condition, I’m glad you put this info up. 🙂

  2. thank you! you have such great and helpful information. my son was diagnosed with celiac not long ago. he felt great the first few weeks of being gluten free and then started feeling bad again. i then learned that after going gluten free, even non celiacs, can start having a reaction to “corny” foods and additives. i have to say that eliminating corn has been a lot harder than eliminating only gluten. one thing i am in search of is ketchup that is free from corn additives. i thought if i bought anything kosher for passover it would be safe, but then noticed corn syrup was still an ingredient, ugh!

  3. Wow, so glad I stumbled upon this. My poor son now 12 was diagnosed with a corn allergy when he was 9 & was so sick. Now that he’s off of it he’s feeling so normal & healthy but it’s so hard on him not being able to join classmates in class parties with the foods & goodies the other moms bring in or what the school is providing for lunch, etc. He’s tried things behind my back & has paid for it dearly. Thank you so much for all your wonderful efforts providing needed information.

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