Wheat, as well as various foods, from eggs to crustaceans to dried fruit, can also be associated with an allergy. Some symptoms of wheat allergy are common to those of two other diseases related to wheat (and other cereals), namely celiac disease and sensitivity to non-celiac gluten. We talk about this topic with Dr. Paoletta Preatoni, gastroenterologist and digestive endoscopist at Humanitas.
From hives to asthma cramps
Wheat allergy is diagnosed in many cases in the pediatric age and it is often resolved by growth. In adults it can also occur in the form of cross allergies with pollen allergy: an individual is sensitive to allergens present in both wheat and pollen, especially grass. A specialist allergological examination with specific examinations such as prick testing and blood tests is indispensable to diagnose wheat allergy: “Celiac disease, wheat allergy and gluten sensitivity are the three clinical manifestations that recognize gluten ingestion as triggers. The symptomatology of the last two is often stackable and occurs immediately after the intake of gluten-containing products, unlike in celiac patients,” explains Dr. Preatoni.
Allergy to wheat in adults is very rare. Symptomatology is either gastrointestinal (especially diarrhea, meteorism and abdominal pain) or extra-intestinal, especially on the skin and respiratory system in an allergy, or neurological and musculoskeletal symptoms in gluten sensitivity “.
Symptoms of wheat allergy therefore include hives, with redness and itching, and angioedema, with subcutaneous swelling especially around the eyes or lips, and then respiratory symptoms such as nasal congestion, difficulty breathing, asthma and anaphylaxis. A particular form of anaphylaxis related to wheat allergy is work-induced anaphylaxis. This may affect patients who ingested wheat-containing foods and had physical activity in the next two to four hours.
The role of immunity
The picture of the symptoms of celiac disease, an autoimmune disease characterized by an immune reaction to gluten intake, is different from patient to patient. It tends to include intestinal symptoms (from abdominal pain to diarrhea to constipation) and extra-intestinal symptoms (headache, chronic fatigue). The clinical history of the patient – continues the specialist – can point towards the suspicion, which in the case of celiac disease and wheat allergy can be confirmed with serological data, while for gluten sensitivity there are no confirmatory tests and the diagnosis is exclusionary”.
Allergens that trigger the immune system’s reaction may be the different proteins contained in wheat, not just gluten. This is the complex protein present in various cereals including rye and barley, which is formed in the processing of cereals, when the flour is mixed with water, and gives the typical elasticity of processed dough. Proteins such as albumin or globulin can also be the trigger factors for wheat allergy.
Wheat allergy like all allergopathies is mediated through antibodies of the IGE class. As mentioned before, in adults, gluten allergy is very rare and the available prick tests are not specific for gliadins (gluten protein) that should always be requested in case of suspicion. In adults, wheat allergy occurs very rarely with only gastroenteric symptoms and generally at least one other allergy is present.
“If there is the confirmation of an effective allergy to wheat – concludes Dr. Preatoni – this should be excluded from the diet to prevent clinically important reactions that can even reach anaphylaxis “.