Corn Allergy Information

Corn is not considered one of the "big eight" allergens--eggs, milk, soy, fish, peanuts, tree nuts, shellfish, wheat--but the incidence of corn allergy is increasing. This may be a result of increased consumption of processed foods by young children, many of which contain corn products. Ingesting corn, touching corn or products containing corn, or breathing in corn particles or pollen, can trigger symptoms of corn allergies. In most cases, symptoms are manageable, but for some people, exposure to corn can trigger a potentially fatal anaphylactic reaction.

Causes

• When someone is allergic to corn, his body develops antibodies to corn proteins. When these proteins are ingested or inhaled, the body's immune system identifies and targets the corn proteins as harmful invaders. This immune reaction is what causes the symptoms of an allergic reaction. Why some people develop an allergy to a specific substance when others do not is not well understood, but genetics may play a role in allergy formation. The American Academy of Allergy, Asthma and Immunology states that early exposure to potential allergens increases the risk of developing an allergy. For this reason, infants should not be fed solid foods until six months of age, and babies with a family history of allergies should wait until after their second birthday to try foods likely to cause allergies, such as eggs, peanuts and shellfish.

Symptoms

• Corn allergies may present typical symptoms of an allergic reaction, such as anaphylaxis, breathing difficulties or asthma, rashes or hives, headaches, tongue and facial swelling and gastrointestinal problems, or they may cause a host of symptoms not always associated with allergic reactions. Atypical symptoms of corn allergies include depression, joint pain, fatigue, eczema, night sweats, recurring infections, hyperactivity in children, concentration difficulties and black circles under the eyes. Not everyone with a corn allergy will react the same way when exposed to the allergen, and symptoms may change over time.

Diagnosis

• Diagnosing an allergy is usually done with allergy testing, either with a skin prick test or through the results of RAST blood testing. However, the results of allergy testing are not always accurate and false negatives and positives can occur. To confirm a diagnosis of corn allergy, doctors recommend eliminating the potential allergen from the diet for at least two weeks to see if there is any change in symptoms. Keeping a diary of foods eaten, along with any allergic symptoms, is also helpful in making a diagnosis.

Treatment

• Treatment of corn allergy is with avoidance of the allergen, antihistamine medications and corticosteroids to reduce existing symptoms. For those with severe allergies to corn, emergency medication, such as an EpiPen, must be carried at all times. Antihistamine and other allergy medications may need to be taken daily, or can be used following ingestion of the allergen or when exposure is likely to occur. Allergy shots are effective for some people.

Considerations

• Avoiding corn is difficult, as corn is used as an ingredient in many foods. Moreover, corn is often difficult to detect on product labels. It is essential to read all food labels carefully if you are diagnosed with a corn allergy and to limit how often you eat outside of your home. Corn syrup is one of the most common sources of corn in foods, and is used in everything from cereals and snacks to sauces and canned soups. Other common ingredients to avoid include corn in any form, baking powder, maize, caramel coloring, cornmeal, cornstarch, dextrin, dextrose, fructose, metodextrins, mannitol, sorbitol and confectioners' sugar. This list is not inclusive.