Gastrointestinal allergyT78.1

Gastrointestinal allergies are allergic diseases (food allergies) that manifest themselves in the gastrointestinal tract. They manifest themselves in unspecific symptoms such as flatulence, flatulence and diarrhoea. Gastrointestinal allergies must be examined by differential diagnosis to distinguish them from food intolerances and inflammatory or functional intestinal diseases.

The prevalence of food allergies is highest during the first two years of a person's life and then decreases. Depending on the type of allergy, they often disappear completely by the age of 6 (allergies to milk, wheat and eggs disappear, while allergies to nuts, fish and crustaceans, among others, usually persist).

Reliable data on the prevalence of food allergies are difficult to obtain; according to recent analyses, 4 to 6 % of children and 1 to 2 % of adults are affected. The prevalence of food allergies is thought to have increased over the last 20 years.

Food allergies are sub-tolerance reactions that are immunologically mediated and occur individually. In the case of an IgE-mediated food allergy, a clinically silent sensitization phase takes place, which results in the formation of allergen-specific IgE. A disturbance of the gastrointestinal barrier can also play a role in the development of a food allergy.

The symptoms of an IgE-mediated reaction usually occur minutes to hours after the absorption of the allergenic substance, delays are caused by the time of transfer. Symptoms of the gastrointestinal tract are nausea, pain, vomiting, diarrhoea, reflux and abdominal colic.

For the diagnosis of a gastrointestinal allergy other gastrointestinal diseases should be excluded. In addition, a detailed medical history must be taken and the allergic predisposition of the patient and 1st degree family members must be clarified.
Patients should keep a dietary record during this phase, including any complaints that may arise. Finally, allergy tests and the measurement of specific IgE in serum follow.

A distinction to food intolerances and malabsorptions, which are not immunologically mediated, is necessary. In addition, (congenital) metabolic diseases, chronic inflammatory intestinal diseases and celiac disease must be diagnostically excluded.
In addition, eosinophilic diseases of the gastrointestinal tract must be considered in the differential diagnosis. Further causes of clinical symptoms of the gastrointestinal tract are dumping syndrome, infectious enteritis, colitis, porphyria, exogenous toxins, irritable bowel syndrome and pseudoallergic reactions.

The treatment of a gastrointestinal allergy consists of the building blocks of nutrition therapy, drug therapy and immunotherapy. It is important, above all, to identify the symptom triggers.