Wheat Allergy

What is Wheat Allergy?

Bread wheat, also known as Triticum aestivum, is a crop that is commonly farmed all around the world. The reason it’s so popular is because it’s easy to grow in a variety of climates, it’s high in nutrients, tastes good, and can be made into a wide range of food and drink items. However, despite these advantages, wheat is known to cause allergic reactions in some people.

Our bodies have a defence system called the immune system, which fights off harmful things like bacteria and viruses. For some people, their immune system mistakenly recognizes wheat as harmful. This causes an allergic reaction. These reactions are caused by substances in our immune system called Immunoglobulin E (IgE) and other immune responses.

These IgE-related reactions to wheat can be quite well-known and can occur either when we eat (food allergy) or breathe in wheat (respiratory allergy).

What Causes Wheat Allergy?

A wheat allergy can be caused by two types of reactions to wheat proteins: IgE-mediated or non-IgE-mediated reactions. In an IgE-mediated reaction, your body creates a type of antibody called IgE in response to wheat. This can be serious, even life-threatening, as it can lead to a severe allergic reaction known as anaphylaxis.

Celiac disease, another condition related to wheat, is a different type of reaction called non-IgE-mediated. In these reactions, the body’s immune cells attack the gut, instead of creating antibodies.

Both types of allergies are identified by their reactions in the body. IgE-mediated reactions include the production of wheat-specific IgE antibodies and can be life-threatening. Non-IgE mediated reactions can result in long-term inflammation where immune cells like eosinophils and lymphocytes (types of white blood cells) damage the digestive tract.

IgE-mediated reactions to wheat can happen in two ways: from eating wheat or from breathing in wheat, such as in a baker’s shop. Children are more likely to have a food allergy to wheat than adults, and this can lead to a serious anaphylaxis reaction, and even a specific type of anaphylaxis that happens during physical activity (called wheat-dependent exercise-induced anaphylaxis, or WDEIA). But, long-term exposure to wheat flour, like what might happen to a baker, can cause a wheat allergy from inhalation, resulting in a condition commonly known as baker’s asthma.

The non-IgE-mediated reactions mainly cause a condition where the esophagus (the tube that connects your mouth and stomach) becomes inflamed with eosinophils, known as eosinophilic esophagitis, or the inflammation of the stomach lining, known as eosinophilic gastritis. They both involve chronic eosinophilic inflammation, which means a long-term inflammation in your body caused by an increased amount of eosinophils.

Risk Factors and Frequency for Wheat Allergy

The exact number of people who have a confirmed allergic reaction to wheat, triggered by a specific type of allergy-related antibody (IgE), is not known. However, it’s estimated that wheat allergies could affect anywhere from 0.2% to 1% of people. This kind of food allergy is more common in children than in adults, especially if wheat is introduced to their diet after six months of age.

The good news is that most children grow out of this allergy – around 65% of them overcome it by the time they turn 12.

In the United States, about 1% to 2% of people have celiac disease. This is a different kind of wheat allergy, not triggered by the IgE antibody. It can cause digestive problems and other symptoms.

• The exact prevalence of people with confirmed IgE-mediated wheat allergies is unknown, but estimates suggest it could be between 0.2% and 1%.
• Children are more prone to develop wheat allergies compared to adults, particularly those who start eating wheat after six months of age.
• About 65% of children outgrow their wheat allergy by the age of 12.
• Celiac disease, a different kind of wheat allergy, affects approximately 1% to 2% of people in the U.S.

Signs and Symptoms of Wheat Allergy

Healthcare providers should assess a patient’s complete history. This should include checking if a patient had any prior allergic reactions to wheat or any breathing allergies caused by wheat flour. If a person experiences symptoms within one to three hours after consuming wheat, the healthcare provider may confirm a wheat allergy by doing a skin prick test or a serum IgE test. These tests involve measuring the levels of specific IgE antibodies to wheat in the body. Other relevant history includes information about the patient’s work, both past and current.

Signs pointing to a wheat allergy might be:

• Skin rash (urticaria)
• Swelling (angioedema)
• Asthma
• Allergic nose symptoms (allergic rhinitis)
• Abdominal pain
• Vomiting
• Worsening of skin inflammation (atopic dermatitis)
• Allergic reaction triggered by exercise (exercise-induced anaphylaxis)

Patients with wheat-dependent exercise-induced anaphylaxis (WDEIA) usually present symptoms within four hours after eating wheat if they partake in intense physical activity. These symptoms can include:

• Itching (pruritus)
• Skin rash (urticaria)
• Swelling (angioedema)
• Face/ skin reddening (flushing)
• Difficulty breathing (dyspnea)
• Difficulty swallowing (dysphagia)
• Tightness in the chest
• Heavy sweating
• Fainting (syncope)
• Headache
• Diarrhea
• Nausea
• Sensation of throat closing
• Abdominal pain
• Hoarseness

Patients with celiac disease, another disorder linked to wheat consumption, may have a different set of symptoms:

• Diarrhea
• Constipation
• Bloating
• Abdominal pain
• Loss of appetite (anorexia)
• Excessive gas (flatulence)
• Weight loss
• Poor growth rate in children
• Anemia
• Specific skin rashes (dermatitis herpetiformis)
• Extreme tiredness (fatigue)
• Osteoporosis

Testing for Wheat Allergy

When someone displays symptoms after interacting with wheat, it is important to get them tested for a wheat allergy. These tests can be performed through a skin prick test or a blood test that looks for a specific type of antibody called IgE, which is an immune response to a potential allergen. However, a positive test for IgE to wheat alone isn’t enough to diagnose a wheat allergy. Some people can test positively for wheat sensitivity but are still able to eat or come into contact with wheat without any symptoms. Further, tests that use wheat flour extract cannot tell the difference between a respiratory allergy and a food allergy to wheat. The exact level of these IgE antibodies in the blood that indicates a true allergy is still unclear.

Sometimes, even children with high levels of IgE can pass an oral food challenge, meaning they can ingest a certain amount of the suspected food allergen without symptoms. This makes linking an IgE level to a wheat allergy more complicated. The evaluation for a wheat allergy should be carefully performed by a healthcare professional, as there is a chance that a severe allergic reaction, known as anaphylaxis, could occur. This reaction may require immediate medication with epinephrine, a hormone that can relieve severe allergy symptoms.

Special tests for specific types of allergies related to wheat may also need to be carried out. For instance, WDEIA is a type of allergy that causes exercise-induced anaphylaxis, a severe allergic reaction triggered by physical activity after consuming wheat. Similarly, people who work in environments exposed to wheat and develop asthma-like symptoms, a condition known as ‘baker’s asthma’, might also need to be tested. Confirming a case of baker’s asthma typically includes a bronchial challenge test, where the person breathes in a solution containing flour at increasingly high concentrations, or inhales wheat flour dust.

Celiac disease, a severe sensitivity to gluten, a protein in wheat, requires another type of test. Typically, this begins with a blood test looking for a certain type of antibody called anti-tTG. If someone has a deficiency of a certain antibody class called IgA, another type of antibody, IgG class anti-deamidated gliadin peptides, can be used as an initial screening. The anti-EMA IgA test, which has a high specificity to active celiac disease, can be used as a confirmatory test after initial screening.

Treatment Options for Wheat Allergy

If you’re allergic to wheat, the best course of action is to avoid eating or inhaling it. For those with celiac disease, which is a disorder triggered by eating gluten (a protein found in wheat), the usual treatment is a diet free of gluten that lasts a lifetime.

If you have been exposed to an allergen and are experiencing a severe allergic reaction, known as anaphylaxis, an immediate injection of epinephrine (also known as adrenaline) can be life-saving. Even after this treatment, it’s important to go to the emergency room for further checks. Additional treatments like antihistamines, glucocorticoids, and beta-agonists might be given at the hospital to further help with the allergic reaction.

Immunotherapy can also be an option, which involves gradually exposing your body to the food you’re allergic to in hopes that it will get used to it and not react as strongly. Oral immunotherapy (OIT) and sublingual immunotherapy (SLIT) both involve consuming small, slowly increasing amounts of the allergen. There’s also epicutaneous immunotherapy (EPIT), which uses a skin patch to deliver small amounts of the allergen to you.

For those with a specific type of wheat allergy, called Wheat-dependent exercise-induced anaphylaxis (WDEIA), carrying emergency medication is necessary. To avoid symptoms, people with WDEIA should also avoid exercising directly after eating wheat. They should also avoid exercising alone or in hot weather and during pollen season.

What else can Wheat Allergy be?

When trying to identify a wheat allergy, doctors look through a wide range of possible diagnoses. Some of these include:

• Non-IgE-mediated food allergy (which means the body’s immune system attacks certain foods)
• Flush syndrome (which could be due to menopause, certain medications, or specific types of epilepsy)
• Restaurant syndromes (which could be caused by certain food additives like sodium glutamate or sulfites)
• Non-anaphylactic shock (a severe reaction that’s not caused by an allergy)
• Syndromes where the body produces too much histamine (which can cause hives or severe itching)
• Nonorganic syndromes (conditions that are caused by mental or emotional factors)
• Hereditary angioedema (a genetic disorder that causes swelling under the skin)
• Anaphylaxis due to progesterone (an allergic reaction to a female hormone)
• Urticarial vasculitis (a form of inflammation of the blood vessels)
• Pheochromocytoma (a rare tumor of the adrenal glands)
• Hyper IgE syndrome (a very rare immune disorder)
• Seizure
• Stroke
• Pseudo-anaphylaxis
• Redman syndrome
• Irritable bowel syndrome

These are only some of the conditions that could mimic a wheat allergy, and the doctor needs to consider all these possibilities to give an accurate diagnosis.

What to expect with Wheat Allergy

An allergy to certain foods that is triggered by IgE (an antibody produced by the immune system), and a specific type of allergy that occurs when wheat is ingested before exercise (known as wheat-dependent exercise-induced anaphylaxis or WDEIA), can negatively affect your quality of life and overall health.

Typically, the allergy to wheat for adults that is mediated by IgE is not severe. However, for people suffering from celiac disease, which is a disorder where the body’s immune system attacks the small intestine when gluten is consumed, sticking to a gluten-free diet could prevent health complications and potentially even fatal outcomes associated with celiac disease.

For celiac disease patients who do not improve even after removing gluten from their diet and undergoing corticosteroid treatment (a type of medication often used to reduce inflammation), their overall health prognosis tends to be quite poor.

Possible Complications When Diagnosed with Wheat Allergy

Celiac disease can be associated with other health conditions like type 1 diabetes, autoimmune thyroid disorders, autoimmune hepatitis, and even neurological disorders, such as epilepsy. Additionally, there are several complications that may develop from celiac disease, including:

• Anemia
• Anxiety
• Joint pain (arthralgia)
• Arthritis
• Weak and poorly formed dental enamel
• Delayed puberty
• Depression
• Fatigue
• Infertility
• Weak bones (osteoporosis)
• Inflammation of the pancreas (pancreatitis)
• Shaky and uncontrolled movements (peripheral neuropathy)
• Short stature

There can also be serious complications like:

• Intestinal T-cell lymphoma related to enteropathy, a condition affecting the small intestine
• Small bowel adenocarcinoma, a type of cancer
• Non-Hodgkin lymphoma, another form of cancer

Preventing Wheat Allergy

If you experience signs or symptoms that suggest you may have a wheat allergy, it is essential to seek medical help as soon as possible as this type of allergy can be very serious and even life-threatening. If you have been diagnosed with a wheat allergy, it is very important to avoid wheat in your diet and always carry a medicine called epinephrine.

Wearing a medical identification bracelet which states your wheat allergy can be very useful, particularly if you ever need emergency care and are unable to communicate this allergy to the medical professionals. If you have a child with a wheat allergy, it’s important to ensure everyone who looks after your child is aware of this allergy. This includes educators and healthcare providers at school or another care setting. They should also be aware of the signs of exposure to wheat.

Regular check-ups with an allergy specialist (allergist) can be very beneficial as they can discuss possible therapy options, such as immunotherapy. This is a type of treatment that aims to train your body to cope with the allergens that trigger your symptoms.

If you have celiac disease, another condition related to wheat, it is recommended to follow a gluten-free diet not just to avoid symptoms, but also to promote overall health. Regular appointments with a doctor specializing in the digestive system (a gastroenterologist) are also advisable.