Wheat allergy

Wheat allergy is an immunological reaction to wheat. In contrast to celiac disease, wheat allergy involves IgE-mediated and/or T-cell-mediated reactions against various wheat proteins, including amylase trypsin inhibitors (ATIs), ω-5 gliadin and lipid transfer protein (LTP). 
 

Wheat allergy can cause mild or severe allergic reactions in various organs. The following symptoms may occur in those affected: Itching or scratching, as well as swelling in the eyes, mouth, nose and throat, hives, neurodermatitis, urticaria and atopic eczema on the skin, allergic rhinitis, shortness of breath and asthma in the lungs and nausea, vomiting, flatulence, diarrhoea and cramps in the gastrointestinal tract. As this is an allergy, severe reactions in the form of anaphylactic shock may also occur. In addition to eating wheat, inhalation of wheat flour dust can also cause an allergy. People who work in the bakery trade in particular are often affected by so-called baker's asthma. People affected by this respiratory disease often suffer from allergic rhinitis and/or asthmatic symptoms, but can tolerate wheat as a food without any problems. If those affected are primarily allergic to the pollen of the wheat, symptoms occur mainly in June.
 

As a rare disease, wheat allergy is rather difficult to diagnose. If suspected, celiac disease with associated villous atrophy should be ruled out first. The medical history of the patient is the basis for further investigations. Following the doctor-patient consultation, it is recommended that a symptoms diary be kept, as well as the determination of specific IgE antibodies against wheat in the blood and various tests (prick test, scratch test, rub test and intradermal test). The last steps of a well-founded allergy diagnosis are the follow-up anamnesis and/or provocation tests. If the test results do not allow a clear conclusion to be drawn, the allergist can subsequently perform a provocation test at the site of the symptoms (e.g. nasal mucous membrane). In the event of a history of severe immediate or life-threatening reactions and positive specific IgE, the patient should not be provoked orally. 
 

In affected children allergic reactions to wheat occur within minutes to hours after the first wheat-containing meals ( baby cereal), although time-delayed reactions can also be observed. The prognosis for the disease is good: Infants with diagnosed wheat allergy can develop tolerance to wheat by school age. However, a wheat allergy can persist if the number of detectable IgE antibodies is high.
 

In rare cases, wheat allergy also occurs as so-called wheat-dependent exercise-induced anaphylaxis (WDEIA). This special form is an IgE-mediated immediate reaction, which is rarely diagnosed in children and more frequently in adults. In the case of WDEIA, allergic reactions up to and including anaphylactic shock occur after consumption of products containing wheat only in combination with physical exertion, alcohol, stress, medication or hormonal factors. Athletes who consume products containing wheat before their fitness routine are particularly affected by WDEIA. Without these trigger factors allergy sufferers do not respond to wheat.  If WDEIA is suspected, a blood test for antibodies is performed to look for the main allergen of this special form - omega-5 gliadin. In addition, a provocation test can be carried out by an allergist, in which not only the wheat protein is administered, but also the supposed trigger is simulated. Eosinophilic esophagitis/gastroenteritis is another special case, in which wheat can be a trigger. In this form of the disease, eosinophilic infiltrates can be detected in the mucous membrane of the affected organs when a specimen is taken.
 

People affected by wheat allergy must avoid wheat, but also pay attention to hidden wheat in packaged products such as ready meals, soups, sauces or sweets such as cookies. Care should be taken with terms such as couscous, bulgur, modified starch, flour and breadcrumbs. According to experts, wheat-like grains such as spelt, green spelt, hulled wheat, single grain and kamut should also be avoided. Gluten-free products may also be unsuitable for people with wheat allergies because the wheat starch used may still contain the wheat protein albumin as an allergen. In principle, desensitization is possible in some cases. There are no drugs for the treatment of wheat allergy as things stand at present.
 

In 2013, a scientist from the Institute of Pathophysiology and Allergy Research at the Medical University of Vienna identified a protein in wheat that is believed to be the cause of the allergic reaction. The protein is called " Alpha Purothionin - Tri a 37", which protects wheat from pests. The study found that patients who have the allergen-specific antibodies (IgE) against "Tri a 37" in their blood have a four times higher risk of having a severe allergic reaction to wheat. The identification of the protein should make it much easier to diagnose and treat wheat allergy, the researcher explained. In addition to wheat, the protein was also found in rye and barley, but not in oats, rice, spelt, soya or sunflower seeds.
 

US researchers investigated the relationship between folic acid concentration and allergic diseases in a study involving 8000 subjects from 2005-2006. It was shown that those who had a higher folic acid level also had lower IgE antibody levels and thus suffered less from allergies and asthma. In contrast, the likelihood of increased IgE antibody levels was 30% higher in subjects with low folic acid levels (below 8 µg / ml).

In 2009, a study by the Helmholtz Centre in Munich investigated whether the intake of vitamin E is related to the occurrence of allergic sensitization and IgE concentrations in serum. In the 366 adults studied, aged 29 to 54 years, the risk of allergic sensitization was significantly reduced with a higher vitamin E intake.

In another study, researchers looked at Vitamin A concentrations in 433 schoolchildren aged 6-18 years who suffered from bronchial asthma. The researchers found that serum vitamin A levels were significantly lower in asthma patients than in 537 controls.

In the context of asthma, a team of researchers at Queen Mary University of London has found that vitamin D products can significantly reduce the risk of a severe asthma attack. The meta-analysis carried out shows that patients with mild or moderate asthma who also consume vitamin D are less likely to have severe asthma attacks with hospital stays. Patients who took the drug for at least six months showed improvement.

Black cumin seed oil (Nigella sativa) has long been used to prevent and alleviate the symptoms of allergic reactions due to its immunomodulating, anti-inflammatory, antioxidant and cytoprotective properties. Clinical studies in patients with allergic rhinitis, asthma or atopic eczema confirm the efficacy of use in this indication. By suppressing inflammatory mediators such as prostaglandins and leukotrienes and by increasing T-cell and killer cell activity, black cumin seed oil also appears to be a suitable therapeutic for autoimmune diseases.

A deficient zinc supply impairs the formation and activity of phagocytes and natural killer cells. As a result, zinc seems to have a direct influence on the risk, duration and intensity of the disease. It is also suspected that zinc inhibits the formation of inflammation-promoting cytokines and thus has a direct influence on the course of infection. Zinc supplementation can be used to strengthen immune functions, especially in older people. As zinc can inhibit the release of histamine from mast cells, it is an important adjuvant therapy for allergies and allergic reactions. Studies have also shown a clear link between food allergies in children and reduced zinc and selenium status.
 

Although there is an intolerance to gluten in coeliac disease, as well as in non-celiac disease gluten sensitivity and wheat allergy, the 3 diseases differ in their reaction to the body.

- Wheat allergy is an IgE antibody associated food allergy to gluten.
- Celiac disease is a T-cell mediated reaction with the corresponding IgA antibodies.
- In contrast, no antibodies are formed in the case of non-celiac disease gluten sensitivity.