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Author:  Australian Allergy CentreSeptember 24, 2015

Corn Allergy

Allergic symptoms of corn allergy develop when an individual’s immune system becomes sensitised and overreacts following the ingestion of corn or foods containing corn-derived products.

Symptoms of Corn Allergy

Physical reactions to corn and corn products can range from mild to severe. Some common symptoms of corn allergy include:
– Hives
– Nausea, abdominal cramping, indigestion, vomiting, diarrheoa
– Nasal congestion, runny nose, sneezing
– Headaches
– Exacerbation of asthma
– Anaphylaxis

Note: Anaphylaxis is life-threatening and can intensify rapidly. Individuals should be treated with adrenaline immediately upon the onset of symptoms.

Diagnosis of Corn Allergy

Corn allergy can be difficult to diagnose, and individuals should always seek professional advice if a corn allergy is suspected.  Corn is a cereal grain, with proteins which are structurally similar to the proteins within other cereal grains such as wheat. This similarity means people with an allergy to one cereal grain can demonstrate positive allergy tests to other cereal grains. Achieving a diagnosis is further complicated by cross-reactivity between cereals and grass pollens. For instance, a corn or grass pollen-allergic patient may display a positive reaction to corn during a food allergy test, without having ever exhibited allergic symptoms when corn is ingested. In this circumstance a positive skin prick test or blood test result may be considered clinically irrelevant, based on the patient’s clinical history.

A food elimination diet is another method sometimes undertaken to determine the presence of corn allergy. Corn and corn-derived products are removed from the diet for a period of time and the individual is monitored for symptom improvement. This should always be done under the supervision of a doctor or dietician.

Management of Corn Allergy

Management of a corn allergy involves eliminating corn from the diet and avoiding all traces of corn. Unfortunately achieving a corn-free diet is not as simple as not eating corn-on-the-cob and corn syrup. Individuals with a confirmed corn allergy must take care to avoid all items which contain corn or corn derivatives, are made from corn, and use corn as part of the preparation or packaging process. In different forms, corn is hidden in a great variety of foods. It is therefore important to read all labels thoroughly prior to purchasing and consuming foods.

Corn-Free Diet

OBVIOUS FORMS OF CORN

- Corn flakes
– Corn flour – used for thickening soups
– Cornmeal
– Corn oil
– Corn starch
– Corn sugars
– Corn syrups – commonly found within confectionary, chocolate and cake
– Popped corn
– Fresh, canned or frozen corn
– Corn fritters
– Crushed corn is used for expanded snack foods such as “Cheezels”, and “Cheese Rings”.

FOODS WHICH MAY CONTAIN CORN AND OTHER FORMS OF CORN

- Baking mixes, pastries, cakes
– Baking powder
– Icing sugar mixture
– Biscuits
– Batters and mixtures for frying foods
– Margarine
– Breakfast cereals e.g. cornflakes
– Breads
– Tortillas
– Sandwich spreads
– Confectionary
– Gelatin desserts
– Chewing gum
– Ice creams
– Soups (creamed, thickened, vegetable, powdered)
– Various prepared meats e.g. deli meats, ham, sausages, hotdogs
– Gravies
– Salad dressings
– Canned mixed vegetables
– Cordials
– Carbonated beverages
– Tea and coffee
– Liquors (bourbon, whisky, gin)
– Wine

HIDDEN SOURCES OF CORN

- Adhesives e.g. envelopes, stickers, tapes
– Some cosmetics and skin cleansers
– Toothpastes
– Vitamin preparations
– Medications e.g. Aspirin
– Laundry detergents
– Paper containers e.g. plates, milk cartons
– Plastic food wrappers (sometimes coated with cornstarch)

It is important to note that self-diagnosis of a food allergy is dangerous and not recommended. Self-diagnosis can lead to unnecessary dietary restriction, and subsequent nutrient deficiencies. If you are concerned you or your child may have a corn or other food allergy, it is recommended you seek the professional advice of a doctor and/or dietician.