Wheat allergy

What is it

The first thing to clarify is that both intolerance and wheat allergy should not be confused with celiac disease, although in some cases the symptoms may be similar and to cause them is the ingestion of wheat or other cereals.

Celiac disease is an inflammation that occurs in the intestine as a reaction to contact with a particular lipoprotein compound contained in cereals, gluten; Wheat allergy is a reaction of the immune system to one or more proteins found in cereals (including gluten) that causes a general inflammatory state.

In most cases it is a real allergy, characterized by the production of antibodies directed against specific protein fractions or by the activation of immune cells; In some subjects, however, there may be, in particular towards gluten, a form of intolerance that causes gastrointestinal symptoms, but not the typical immune phenomena of allergy or celiac disease (in these cases we speak of non-celiac gluten sensitivity).

The most typical form of wheat protein allergy affects predominantly in early childhood and tends to regress with growth; In adulthood there are mainly cases of non-celiac sensitivity to gluten, as well as an allergic form that is triggered by physical exercise.

Causes

Wheat (cereal of the genus Triticum, belonging to the botanical family of Gramineae) is one of the foods most often implicated in food allergies.

The proteins present in the kernel (grain) that can cause an allergic reaction are many (at the moment about forty possible allergens have been identified): the main ones are gluten, albumins, globulins, gliadins. Gluten, which is the most frequently involved allergen, is also present in other cereals: especially in spelt, barley, rye and kamut. Among gliadins, one in particular, omega-5 gliadin, is responsible for the most severe allergic form, the so-called grain-dependent anaphylaxis.

The body’s exposure to wheat allergens, which usually occurs through ingestion and more rarely by direct contact or inhalation (for example for occupational reasons), can cause different types of immune reactions, such as the production of specific antibodies of the IgE type or the activation of T lymphocytes.

Symptoms

The clinical manifestations depend on the type of immune response triggered by exposure to the allergen: they can occur immediately after contact (immediate reactions) or after a few hours (delayed reactions). They can be generalized (anaphylactic shock), or localized in different parts of the body, causing numerous disorders:

In children, forms with cutaneous manifestations are frequent and, especially in neonatal age, those with gastrointestinal symptoms; In case of allergy to omega 5-gliadin, the most severe generalized form (wheat-dependent anaphylaxis) may also occur. In about two-thirds of cases, wheat allergy usually disappears by the age of 10 to 12.Although less frequently, a wheat allergy may also be present in adulthood: in most cases a form with gastrointestinal manifestations is observed (caused by a reaction to gluten proteins) but it is possible that the so-called “wheat-dependent anaphylaxis triggered by physical exercise” (performed after wheat ingestion), which is caused by omega 5-gliadin, is also triggered.

Diagnosis

Once celiac disease has been ruled out with the appropriate tests, the diagnosis of wheat allergy can be pursued through classic allergy tests:

• the assay of specific IgE antibodies against wheat proteins
• skin tests (Prick Test) with specific allergens
• provocation tests (aimed at highlighting the temporal relationship between exposure to food and the onset of symptoms)
• elimination tests (aimed at detecting the disappearance of symptoms once food intake has stopped).

Given the extreme variety of potential allergens present in wheat and related cereals, laboratory tests (which are programmed to detect reactions to individual allergens) are not always able to ascertain the existence of a precise allergy. Even more so in cases where the symptoms are not of allergic origin, but induced by a non-celiac gluten sensitivity. In the diagnosis orientation phase, it is important to keep regular note of the evolution of symptoms and of any episode of exposure to the suspected food.

Treatment

The most effective measure is certainly the prevention of allergic reaction and consists in refraining from taking foods containing the allergen that causes it. This means excluding from your diet all processed products (food or beverages and possibly supplements / drugs) in which wheat derivatives are present and, in case of allergy or sensitivity to gluten, also of other cereals that contain it.

The individual allergic manifestations must obviously be treated at the moment with the appropriate drugs, bearing in mind that the symptoms that make suspect a generalized reaction (anaphylactic shock) – namely diffuse itching, swelling of the eyes and face, feeling of tightness in the throat, difficulty breathing, vomiting, palpitations, dizziness, loss of consciousness – require immediate medical intervention.