Food allergy – symptoms, allergens and therapy

Definition Food Allergy

A food allergy is an allergic reaction caused by parts of certain foods. Allergic reactions are exaggerated reactions of the immune system to actually harmless components of our environment. Food allergies should not be confused with frequent intolerances, e.g. to lactose (lactose intolerance), which are based on the fact that the body lacks an important enzyme for the breakdown of the corresponding substance. These are not allergies, as the immune system is not active here.

Pathogenesis

Food allergies are triggered by contact with actually harmless food components. These are usually ingested orally, i.e. through the mouth. In particularly severe cases, however, contact with the skin is sufficient.

The immune system responds to these so-called allergens as if they were bacteria or viruses harmful to the body. At the first contact with the allergen, the body scans the substance precisely with the help of certain cells so that it can recognize it accurately from the second contact and initiate appropriate reactions. Symptoms of an allergic reaction that only occur after the second contact can occur, for example: These reactions, which feel very different for the person affected, are all due to the same mechanisms in the respective tissues.

Food allergies are often allergies of the so-called type 1 or immediate type: mast cells, certain white blood cells, carry receptors, i.e. proteins in which the allergen fits like a key in a lock, on their surface. As soon as a certain amount of the allergen is present, the cells release certain substances, so-called mediators, which signal the body and other immune cells that the substance must be removed or rendered harmless. This includes making the blood vessels more permeable.

Therefore, more fluid reaches the tissue surrounding the cells. Skin and mucous membranes (also mucous membranes within the body, e.g. in the intestine) swell. Fluid comes to the surface.

This leads to a runny nose in the case of hay fever and also to diarrhoea in the case of allergens in food. The swollen tissue also creates constrictions, which can make breathing more difficult. Not everyone has allergies, so it is assumed that genetic factors play an important role. Especially with this form of allergy, this is likely, since it occurs very early.

  • The skin as so-called hives,
  • The mucous membranes (especially in the nose) and in this particular case
  • Also as gastrointestinal complaints.