The human body is a universal system that immediately reacts to the intake of substances that are unnecessary for it. This is manifested by an anaphylactic or anaphylactoid reaction. Manifestations of anaphylaxis depend on the individual sensitivity of the body to the allergen and the strength of the released mediators. Read about the factors and types, causes and manifestations, as well as the treatment of an anaphylactic reaction in the article estet-portal.com.
Anaphylaxis: factors contributing to the development of an anaphylactic reaction
An anaphylactic reaction is the process of an immediate-type reaction that is mediated by IgE. This reaction is conditionally divided into 3 types:
1) binding of an antigen to two IgE molecules on the surface of a basophil or mast cell membrane and activation of these cells;
2) release of mediators by activated basophils and mast cells;
3) the action of reaction mediators on the vascular wall, activation of the action of eosinophils, platelets, neutrophils on the blood coagulation system.
An anaphylactoid reaction is clinically very similar to an anaphylactic reaction, but is due to interactions with different substances, such as C3a and C5a. It is these substances that activate basophils and mast cells, provoke their degranulation and act on the organs – targets.
Several factors contribute to the development of anaphylactic reactions:
- Psycho-emotional factors – stress, depression, emotional stress.
- History of allergic diseases – allergic rhinitis, bronchial asthma, atopic dermatitis, eczema.
- Pathological conditions of the gastrointestinal tract and / or changes in the mode and diet.
- Genetic predisposition.
- The load on the fetus during pregnancy (alcohol and maternal smoking) provokes the child's predisposition to the development of anaphylaxis.
Anaphylactic reactions develop rapidly and it is often not possible to find out the cause before starting treatment. There are several reasons for the development of anaphylactic reactions.
Causes of anaphylactic reactions: types of allergens
Anaphylactic reactions occur when certain foods, medications, or insect bites are ingested, which are allergens.
The development of the reaction begins with the release of mediators of histamine, leukotrienes, bradykinin, tryptase, platelet activating factor, acid hydrolases. Against the background of the formation of such complexes, a generalized reaction develops.
Pathogeny of anaphylactic reactions in case of allergen intake
Histamine – causes swelling of the mucous membrane of the respiratory tract, reduces vascular tone and increases their permeability, causes spasm of the smooth muscles of the bronchi, increases the secretion of mucus in the respiratory tract, increasing their obstruction, reduces BCC due to a decrease in venous return. Erythema, edema, urticaria appear against the background of increased permeability of the vascular wall.
Read also: Optimizing the choice of antihistamines from the point of view of pharmacoeconomics
Kalikrein – takes part in the synthesis of kinins, which reduce blood pressure and increase permeability.
Eosinophil chemotaxis anaphylactic factor increases eosinophil influx. They synthesize active substances that block mast cell mediators.
Prostaglandins increase vascular permeability and smooth muscle tone.
Clinical manifestations of an anaphylactic reaction upon exposure to an allergen
In the process of development of an anaphylactic reaction, the upper respiratory tract, skin, mucous membranes, gastrointestinal tract, bronchi, central nervous system and cardio – vascular system. Changes in these organs and systems are provoked by the action of certain mediators.
Manifestations on organs and systems of anaphylactic reaction:
- Leather – erythema, Quincke's edema and urticaria appear.
- Upper Respiratory Tract – copious nasal discharge. Swelling of the larynx, pharynx, tongue, wheezing, hoarseness, sneezing.
- Gastrointestinal tract - nausea, dysphagia, vomiting, diarrhea, cramping abdominal pain, increased intestinal motility.
- Mucoid – congestion and itching in the nose, pallor or hyperemia. Cyanosis, swelling of the eyelids.
- Bronchi – increased secretion of mucus, shortness of breath, bronchospasm.
- CNS – convulsions, restlessness.
- Cardily – vascular system – arterial hypotension, heart failure, tachycardia.
The first symptoms appear within an hour after the allergen enters the body. The intensity of the reaction does not depend on the type of allergen and its dose. The speed of the process is affected by the route of introduction of the allergen.
The main drugs for the treatment of anaphylactic reaction
There are no fundamental differences in the treatment of an anaphylactic reaction and an anaphylactoid reaction. Therefore, at the first sign of anaphylaxis, it is necessary to immediately begin to provide medical assistance to a person.
Medications used to help with an anaphylactic reaction:
- Intravenous corticosteroids.
- Vasoconstrictors (dopamine, norepinephrine).
- Glucagon.
- Ranitidine for intravenous infusion.
- Dimedrol for infusions.
- Adrenaline.
- B-adrenergic stimulant.
- Infusion solutions.
Combinations of medicines are prescribed by the doctor individually for each patient, depending on the severity of the process and the severity of the symptoms of a particular system.
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