What foods can i eat with a corn allergy
Allergic reactions to corn can take diverse forms. Common symptoms include:
- Itching, particularly in or around the mouth (oral allergy syndrome), but may be generalized as well
- Hay fever-like symptoms: sneezing, nasal congestion, runny nose
- Nausea and/or vomiting
- Abdominal pain
- Wheezing, asthma
- Flushing or reddening of the skin
Anaphylaxis may also happen and can include symptoms such as:
- Rapid heart rate
- Swelling and/or tightness of the lips, tongue, throat, neck, or face
- Hoarse voice
- Lethargy, confusion, or loss of consciousness
- Difficulty breathing
- A sense of impending doom
What causes food allergies?
Food allergies happen when the immune system – the body’s defence against infection – mistakenly treats proteins found in food as a threat.
As a result, a number of chemicals are released.
It’s these chemicals that cause the symptoms of an allergic reaction.
Almost any food can cause an allergic reaction, but there are certain foods that are responsible for most food allergies.
Foods that most commonly cause an allergic reaction are:
- tree nuts
- some fruit and vegetables
Most children that own a food allergy will own experienced eczema during infancy. The worse the child’s eczema and the earlier it started, the more likely they are to own a food allergy.
It’s still unknown why people develop allergies to food, although they often own other allergic conditions, such as asthma, hay fever and eczema.
Read more information about the causes and risk factors for food allergies.
Unlike some other food allergies (nuts, shellfish, and wheat, for example), the exact causes of corn allergy aren't known.
It's thought that a combination of genetic factors, environmental factors, and epigenetic factors (the interaction of genetics and the environment) are at play.
Corn is a cereal grain that contains a protein, zein, which is the suspected culprit in this allergy. A reaction occurs when the body recognizes this protein as foreign and releases immunoglobulin E (IgE), antibodies to attack the protein.
IgE then stimulates cells in the immune system to secrete substances such as histamines that are responsible for the symptoms.
Allergic reactions can happen as a result of eating both raw and cooked corn, as well as foods manufactured with corn products. Not every corn products contain zein, but it can be hard to know when it is present, as current food labeling does include a "corn free" designation.
Even coming into contact with surgical gloves or intravenous fluids that contain corn can be problematic. Those who own corn allergy may also react to corn pollen, grass pollen, and cornstarch (typically with hay fever (allergic rhinitis) and/or asthma).
People who own asthma, eczema, hives, hay fever, or other food allergies appear to be at greater risk.
A family history of these conditions is also associated with a higher risk, particularly when a sibling has a corn allergy.
It's uncertain exactly how common corn allergy is, but some researchers believe it's underdiagnosed.
A 2016 study done in Pakistan found the rate to be 0.86, or almost 1 percent of the population. In the study, a diagnosis of allergy was confirmed by a food challenge.
One study in Honduras of only 50 adults found the prevalence to be 6 percent, but there's currently no excellent estimate of the incidence in the United States. Since corn is present in so numerous products (found in roughly 75 percent of processed foods), minor symptoms could be easily overlooked as due to something else.
In the most serious cases, a person has a severe allergic reaction (anaphylaxis), which can be life threatening.
Call 999 if you ponder someone has the symptoms of anaphylaxis, such as:
- trouble swallowing or speaking
- breathing difficulties
- feeling dizzy or faint
Ask for an ambulance and tell the operator you ponder the person is having a severe allergic reaction.
For mild allergic reactions, treatment generally consists of managing the symptoms alone until the allergic reaction is done.
For anaphylactic reactions, epinephrine (an EpiPen) is the only treatment available, along with immediate medical care in an emergency room.
Anaphylaxis is a life-threatening emergency and immediate medical treatment is needed.
Call 911 immediately if you suspect you or a loved one may be having such a reaction.
Bird JA, Jones S, Burks W. Food allergy. In: Wealthy RR, Fleisher TA, Shearer WT, et al, eds. Clinical Immunology: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 45.
Du Toit G, Sayre PH, Roberts G, et al; Immune Tolerance Network LEAP-On Study Team. Effect of avoidance on peanut allergy after early peanut consumption. N Engl J Med. 2016;374(15):1435-1443. PMID: 26942922 www.ncbi.nlm.nih.gov/pubmed/26942922.
NIAID-sponsored expert panel, Boyce JA, Assa’ad A, et al.
Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel. J Allergy Clin Immunol.
2010;126(6 Suppl):S1-S58. PMID: 21134576 www.ncbi.nlm.nih.gov/pubmed/21134576.
Sicherer SH, Lack G, Jones SM. Food allergy management. In: Adkinson NF Jr, Bochner BS, Burks AW, et al, eds.
Middleton’s Allergy: Principles and Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 84.
Togias A, Cooper SF, Acebal ML, et al. Addendum guidelines for the prevention of peanut allergy in the United States: report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. J Allergy Clin Immunol. 2017;139(1):29-44.
PMID: 28065278 www.ncbi.nlm.nih.gov/pubmed/28065278.
A food allergy is when the body’s immune system reacts unusually to specific foods. Although allergic reactions are often mild, they can be extremely serious.
Symptoms of a food allergy can affect diverse areas of the body at the same time. Some common symptoms include:
- swelling of the face, around the eyes, lips, tongue and roof of the mouth (angioedema)
- an itchy sensation inside the mouth, throat or ears
- a raised itchy red rash (urticaria, or «hives»)
Read more about the symptoms of food allergies.
Diagnosis and Testing
Diagnosing food allergies is significant, as the results can own a significant impact on what a person eats each and every day.
That said, the diagnosis of corn allergy can be challenging.
Allergy testing with blood tests and skin tests can be inaccurate, with untrue positive tests occurring often. Such a result, however, does place a person at a higher risk for an allergic reaction to that food and should be considered along with other findings.
A careful history is often the most dependable indicator of a corn allergy, with symptoms of an allergic reaction occurring after eating corn or foods containing corn.
The history, however, can be hard to assess for a few reasons:
- Corn is present in a vast number of foods and in diverse amounts.
- Signs and symptoms are non-specific and may easily be dismissed as a freezing virus, a rash due to irritation, or an allergic reaction due to something else.
With mild symptoms, keeping a food diary is often an excellent start. This involves recording foods that are eaten, when they are eaten, and any symptoms you experience.
An elimination dietcan also be extremely helpful.
With this, the foods that are eaten are greatly restricted, and then individual foods are slowly added back in at specific intervals so that a reaction, if present, can easily be traced back.
The diet often requires a commitment of a minimum of two weeks and often more to identify potential food allergies. If a corn allergy is suspected, a food challenge (eating corn) may be considered, but should only be done under the guidance of an allergist.
Consulting with an allergist who specializes in food allergies early on can be extremely helpful, and is imperative if you own had any symptoms suggestive of an anaphylactic reaction.