An allergic reaction to corn in the United States is extremely low, with an estimated prevalence of 0.016 percent in the general population, according to the Corn Refiner's Association. The symptoms of an allergic reaction to corn are similar to other food allergies, with skin inflammation and dermatitis commonly cited in sensitized individuals.
Immunologic Response to Corn
An allergic reaction to corn occurs when the immune system mistakenly identifies the lipid proteins in corn as foreign and dangerous. The immune system mounts an IgE mediated attack against the lipid proteins, and activates and mobilizes pro-inflammatory cells to the inflammation site. These immune cells, primarily basophils and mast cells, perpetuate the immune response by releasing histamine into the bloodstream and surface of the skin. Histamine dilates and increases blood vessels, allowing fluids to move to the surface of the skin. It also increases the contraction of smooth muscles in the upper respiratory tract, and digestive tract.
The release of histamine dilates and increases the permeability of blood vessels and capillaries, thereby allowing fluids and toxins to move to the surface of the skin. A skin rash involved with hives can appear anywhere on the body. The hives are typically red, itchy and raised with a pale center, and can migrate throughout the body. Hives and the accompanied swelling typically appears within 24 hours of ingesting corn or corn derived products. Atopic dermatitis, also known as eczema, is another skin rash commonly observed during an allergic reaction to corn. This skin inflammation typically appears on the knees, elbows and face, and is characterized raised, itchy, scaly patches that may leak fluids. The skin eventually becomes cracked and thickened because of the scratching and itching.
Treatment of an Allergic Skin Reaction to Corn
The most effective treatment for corn allergy is avoiding corn or corn-derived products. A corn-free diet requires the elimination of corn flour, corn starch, cornmeal and corn. Since corn is used as an additive in many different food products, check the label of the food product and avoid eating meals with bleached flour, corn syrup, corn oil, corn sugar, citric acid, acetic acid, fructose and dextrose. If you accidentally ingest corn and develop an allergic skin reaction, you may not need treatment if the symptoms are mild. Over the counter corticosteroids, such as hydrocortisone, as well as second generation antihistamines, including Zyrtec, are effective in reducing the inflammation and itching.
Testing for an Allergic Skin Reaction
Due to the scarcity of an allergic reaction to corn, your physician may need to perform an allergy test. A skin test may be given by your physician to ensure correct diagnosis. You will be injected with a small amount of the lipid protein from corn on your forearm or upper arm. After a period of 15 to 20 minutes, your physician will be able to determine if you are allergic to corn based on if whether or not you have swelling, redness or develop hives at the injection. A blood test may also be conducted to determine the level of circulating IgE antibodies in response to corn. A provocation test in which you are given corn or corn-derived products under medical supervision may be used to provoke an allergic reaction. These tests should only be performed by a physician.