Wheat allergy is an immune system reaction to the proteins found in wheat. Symptoms can range from allergic rhinitis and gastric distress to the life-threatening allergic reactionknown as anaphylaxis. Proteins found in wheat that trigger symptoms include:
Albumin
Globulin
Gliadin
Glutenin (gluten)
Consumption of food triggers most allergic reactions related to wheat, although inhalation of flour can also cause symptoms (a condition known as baker’s asthma). Symptoms usually appear within minutes to a few hours of exposure.
The only effective way to prevent symptoms related to wheat allergies is to avoid all foods that may contain the allergens. This can be difficult, as wheat is found in many food products. A dietician can help plan a diet safe for those who are allergic to wheat.
About wheat allergies
Wheat allergies are immune system reactions to the proteins found in wheat, including albumin, globulin, gliadin and glutenin (gluten). Most often, the source of symptoms is wheat consumed in food. However, inhalation of flour containing wheat can also cause reactions (a condition known as baker’s asthma).
In people with wheat allergies, the immune system mistakes wheat protein for a harmful substance and releases antibodies called immunoglobulin E (IgE). As a defense against the invader, the IgE antibodies cause certain histamines to be released into the blood stream. These histamines result in the unpleasant allergic symptoms most people associate with wheat allergies.
Wheat allergy tends to affect people from families with a history of allergies such as allergic rhinitis. It is most common in infants, who often outgrow symptoms within the first few years of life. Symptoms of wheat allergy may be mild and mimic those of allergic rhinitis. However, in some cases they can be more serious, manifesting as anaphylaxis.
The only effective treatment for wheat allergies is to completely remove wheat products from the diet. By practicing diligent avoidance, an individual can successfully remove the threat of a wheat–related allergic reaction.
Because wheat is so prevalent in food products, it can be difficult to avoid. Dietitians can help patients plan meal menus that are safe. In addition, patients must be vigilant in reading ingredient lists while shopping, and ask restaurants about food preparation techniques and ingredients.
Alternatives to wheat also are available. They include:
Flours made of corn, potato, barley, rye, oat, soy or rice
Rye meal
Rolled oats
Potato starch
Sago
Arrowroot starches
Cross-reactions may occur in some patients with wheat allergy. Wheat is a member of a very large plant family (Gramineae) that includes grasses and most grains. Some people with wheat allergies may not be able to consume other grain–based foods from this family because of an allergic reaction to the shared protein. Grains that are common alternatives to wheat but may cause cross-reactions include barley, rye and oats.
Potential causes of wheat allergies
Wheat can be found in a wide variety of food products. This can make avoiding wheat difficult for those who are allergic to the grain.
To find out if a food contains wheat, individuals should always check the ingredient label. To avoid eating a product that contains wheat, individuals should stay away from products that contain:
Other foods or ingredients that may contain wheat proteins include:
Gelatinized starch
Hydrolyzed vegetable protein
Modified food starch, modified starch
Natural flavoring
Soy sauce
Starch
Vegetable gum, vegetable starch
People with wheat allergies must be careful to read the labels of all food products. Wheat can often be found in unlikely food products. For example, some hot dogs, imitation crab meat and ice cream contain wheat.
Related allergies and conditions
Wheat allergy is closely related to wheat intolerance, which is a physical reaction caused by an inability to digest wheat proteins. Wheat intolerance differs from an allergy in that an immune system response does not take place in a person with wheat intolerance. However, people with wheat intolerance also avoid wheat products to control symptoms.
Celiac disease, also known as celiac sprue, is a permanent, nonallergic reaction to gluten. It generally is genetic and is believed to result from an abnormal enzyme in the mucosal cell (part of the mucosa, which lines the body’s hollow organs and cavities), an immunity defect or a defect in the mucosal cell membrane. Celiac disease makes it very difficult to properly absorb vital nutrients from food. Usually, people with celiac disease find that consumption of gluten damages the cells lining the small intestine.
Symptoms of celiac disease include diarrhea, abdominal pain and distension and weight loss. Those with celiac disease must avoid all grains that contain gluten, including wheat, spelt, rye, oats and barley. Additional, non-food sources of gluten may be found in medicines, vitamins and the adhesive on envelopes.
Irritable bowel syndrome (IBS) is a disorder that interferes with the normal functions of the large intestine. IBS symptoms include constipation, diarrhea and gastrointestinal distress. These symptoms may be incorrectly interpreted as a food allergy, including an allergy to wheat. IBS is not related to food allergies. However there may be particular foods that trigger IBS symptoms, including wheat. Patients with IBS may learn what foods trigger their symptoms and in consultation with a physician develop a balanced diet that excludes the problem foods. A dietician can also help plan a diet safe for those who are sensitive to wheat.
Dermatitis herpetiformis is an itchy rash that is triggered by gluten intolerance. The symptoms do not usually include gastrointestinal distress. This condition is treated through a strict avoidance of gluten in combination with certain medications.
A number of allergies common to infants, including wheat allergies, usually disappear over time. Symptoms related to these allergies tend to vanish by age 3. Such allergies include:
Cow’s milk
Eggs
Fish and shellfish
Corn
Berries
Soy
Tomatoes
Citrus fruits
Signs and symptoms of wheat allergies
Wheat allergy can trigger symptoms that range from the relatively minor to the more potentially serious. Symptoms typically appear within minutes of eating wheat protein, though some reactions are known to occur up to several hours later. Typical symptoms include:
Gastric distress such as oral allergy syndrome, abdominal cramps, nausea and vomiting
Eczema, hives or angioedema
Allergic rhinitis
Asthma
Anaphylaxis
Diagnosis, treatment and prevention
Diagnosing wheat allergy can be tricky. Wheat is prevalent in many processed foods, making it difficult to determine its role as a potential allergen. In diagnosing a wheat allergy, a physician will conduct a medical examination of the patient as well as compile a medical history and a list of symptoms.
If an allergy is suspected, the physician will perform one or more of the following allergy tests:
Skin test. This test involves scratching, pricking or injecting an individual’s skin with a wheat extract. The tested area will react with redness or swelling to indicate an allergic response. This test can be too dangerous to use on highly sensitive individuals.
RAST (radioallergosorbent test). This type of blood test allows a laboratory to directly test a blood sample from an individual in an attempt to detect antibodies that correspond to a wheat allergy. This test can be used on those people who have reactions that are too sensitive for a skin test.
Elimination diet. This test involves removing wheat from an individual’s diet for several weeks to see if allergic reactions persist. If the reactions do indeed stop, it can be presumed that wheat is the culprit.
Blinded food challenge test. Different foods are placed within capsules to hide their identity. The patient consumes the capsules and the physician looks for signs of an allergic reaction. This is considered the most effective way of determining the cause of a food allergy because it supplies the most convincing results. Since the patient is unaware of what foods they are consuming, their inherent bias cannot influence the results. Although this testing method is more reliable than open testing, it is time–consuming and difficult. It is often reserved to confirm suspicions that a patient's symptoms are not caused by a food allergy.
In addition, a food diary may be kept by someone with a suspected wheat allergy. This diary is used to keep track of all foods consumed by the patient and record what, if any, symptoms are experienced after consumption. It can be a useful tool for the patient’s physician to refer to in diagnosis.
Once a physician has pinpointed wheat as a problem allergen, patients should remove all wheat and wheat-based products from their diet. The services of a dietician may be necessary to ensure that wheat is kept out of the patient’s diet and necessary nutrients are provided.
The only form of treatment for wheat allergy is the complete removal of problem foods from the diet, known as avoidance. There are no drugs available that can prevent a wheat allergy from taking place.
Patients can also try to avoid wheat by checking ingredient labels on foods at the grocery store, and asking about ingredients and preparation techniques at restaurants. Consistently reading labels is vital because companies may add or delete ingredients from time to time, and may add or delete warnings. Patients should not assume that a label checked six months ago will appear the same. Patients should also learn alternate names that indicate the presence of wheat. This will help prevent the accidental consumption of wheat. A number of food companies have toll-free customer service centers to answer questions about specific ingredients and to provide nutrition updates about their products.
New legislation may make it easier for people to determine if a food item contains a potential allergen. As of January 2006, food manufacturers are required by the Food & Drug Administration (FDA) to clearly list food allergens on their product labels.
Various drugs can help treat symptoms related to wheat allergy once they have appeared. These include antihistamines, corticosteroids, mast cell stabilizers and epinephrine.
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about wheat allergies:
Do my symptoms suggest that I am allergic to wheat?
What tests will be used to determine if I have a wheat allergy?
Are wheat allergies dangerous to my overall health?
What treatment options are available to me?
What is the best way to prevent an allergic reaction while dining out?
What types of foods commonly contain wheat?
Is it safe to eat a small amount of wheat once in a while?
What ingredients should I look for when reading product labels?
What should I do if I accidentally eat wheat?
Are my children more likely to develop wheat allergies because I have the condition?
