An allergy to corn occurs when your immune system mistakes corn or a corn product for something that’s harmful. In response, it releases antibodies called immunoglobulin E (IgE) to try to neutralize the allergen. Your body identifies the allergen and signals the immune system to release histamine and other chemicals. Allergy symptoms are caused by this reaction.

Corn allergy is uncommon. It can occur with exposure to corn or corn products, like high fructose corn syrup, vegetable oil, or cornstarch. Laboratory researches has shown cross reactivity with other similar allergens like rice, wheat, or soy. However, experts note that in humans, studies have failed to show that this cross reactivity causes significant allergic reactions.

Keep reading to learn how to detect a corn allergy.

Allergic reactions to a food like corn can vary. The reaction may be uncomfortable for some people. For others, the reaction may be more severe and even life-threatening.

Symptoms usually appear within minutes or up to two hours after consuming corn or corn products, and can include:

  • tingling or itchiness in the mouth
  • hives or rash
  • headache
  • swelling of lips, tongue, throat, face, or other parts of the body
  • difficulty breathing, with wheezing or nasal congestion
  • dizziness, lightheadedness, or fainting
  • digestive problems like nausea, vomiting, or diarrhea

A severe allergic reaction to corn can result in anaphylaxis, which is life-threatening. Symptoms include:

  • loss of consciousness
  • rapid and irregular pulse
  • shock
  • difficulty breathing due to swelling of the throat and air passages

It’s important to seek medical help right away if you have a severe corn allergy, or experience any of these symptoms.

See your doctor if you experience symptoms of a corn allergy. Your doctor will take a history of your symptoms and family health, and note if you have a history of asthma or eczema and any allergies. The information will determine if your reaction is caused by corn or something else. You will also undergo a physical exam. Your doctor may recommend certain tests, like blood tests.

It can be difficult to avoid corn because many food products contain corn or corn product. For some people, even touching the allergen can cause a reaction.

One way to prevent an allergic reaction is to eat food you make yourself. When eating out, ask your server to check with the chef about what ingredients are used in dishes and about the food prep process.

If you have an allergic reaction to corn, sometimes trying to avoid it isn’t enough. Corn products, like corn starch, may be hidden in food or used as sweeteners in drinks. Be sure to read all food labels carefully.

Corn products are usually found in the following items:

  • baked goods
  • beverages or sodas
  • candies
  • canned fruits
  • cereals
  • cookies
  • flavored milk
  • jams and jellies
  • luncheon meats
  • snack foods
  • syrups

Food products generally indicate when corn is included in the ingredients. Steer clear of anything with the words corn (such as corn flour or corn syrup), hominy, masa, or maize.

Other ingredients that may indicate the presence of corn include:

  • caramel
  • dextrose
  • dextrin
  • fructose
  • malt syrup
  • modified food starch and vinegar

Most people with food allergies are unlikely to be cured, but there are ways to reduce the risks of allergic reactions.

If you have already experienced a severe allergic reaction to corn, wear a medical bracelet or necklace. This will help others know that you have an allergy to corn. The medical bracelet or necklace is helpful in situations where you have an allergic reaction and are unable to communicate to others about your condition.

If you’re interested in reading about others’ experiences with food allergies, we’ve rounded up some of the best food allergy blogs.