When we talk about ‘allergies’ today, we usually mean the immune reactions of type I and type IV. Both types differ with regard to the development of the disease, the speed of the symptoms, the clinical pictures and the allergens that trigger them. Also the diagnostics and the therapy of both types is different.
Before it comes to an allergic reaction, the body and the immune system usually had multiple contact with the allergens, which may be years ago. As early as the 1960s, Coombs and Gell divided the previously known pathological immune reactions according to their pathogenesis into 4 different types. Let us have a look at two of those four allergic immediate reactions.
This is the ‘classic’ immediate allergic reaction whose symptoms generally occur within 15-20 minutes. The following symptoms can be mentioned: hay fever (allergic rhinitis), conjunctivitis (conjunctivitis), hives (urticaria), gastroenteritis (gastroenteritis), allergic asthma and, as the most dangerous manifestation, anaphylaxis (anaphylactic shock).
A typical feature of a type I allergy is the participation of antibodies of the class immunoglobulin E (IgE) in the disease process. IgE is not a direct trigger of allergic symptoms, but it mediates the release of the so-called allergic mediators from certain cells of the immune system, the best known is the histamine. The mediators then trigger the allergic symptoms. The triggering allergens of the type I reaction, with a few exceptions, belong to the group of proteins (proteins) and mostly originate from our natural environment: e.g. pollen from wind-pollinated plants, mites, animal hair, mold, food, insecticides.
Allergies are diseases of the immune system. More specifically, it is hypersensitivity reaction to actually harmless substances that are classified by the immune system of the allergy sufferer as ‘worth fighting’.
Type I allergies are those of immediate type, in which the symptoms usually occur very quickly, usually within minutes or hours after allergen contact.
But before the allergic symptoms appear for the first time, the immune system has often been in contact with the allergen already. This phase, in which the immune system gets to know the foreign substance and classifies it as ‘curing is called the sensitization phase. A whole series of different immune cells play a role here.
