Therapeutic measures for acute allergic reactions should include the early elimination of the allergen, anti-allergic therapy, restoration of impaired respiratory functions, blood circulation and other body systems.
To stop further intake of the substance that caused the development of hypersensitivity, it is necessary to stop the administration of the drug, serum or blood substitute (with intramuscular and intravenous injections, infusions), reduce the absorption of the allergen (application of a tourniquet above the injection site or insect bite, circumcision of this area using a solution adrenaline).
Antiallergic therapy involves the use of antihistamines and glucocorticosteroid hormones topically, orally or parenterally. The specific dosages of the drugs and the method of their administration depend on the localization of the pathological process, the severity of the acute allergic reaction and the condition of the patient. Symptomatic therapy is aimed at the correction of impaired body functions and, above all, respiration and blood circulation.
So with bronchospasm, bronchodilator and anti-inflammatory drugs are administered by inhalation (ipratropia bromide, salbutamol, etc.), with severe arterial hypotension, vasopressor amines are prescribed (dopamine, noradrenaline) with simultaneous replenishment of the circulating blood volume.
In severe cases, emergency care is provided in the intensive care unit of a hospital with the use of special equipment that supports the function of blood circulation and respiration. After stopping the acute manifestations of allergic reactions, treatment is carried out by an allergist-immunologist with the use of an individually selected scheme of drug therapy, compliance with an elimination diet, and, if necessary, an ASIT.
Acute allergic reactions are diseases that develop in the presence of an increased sensitivity of the immune system to allergens entering the body from the outside. Usually, signs of an immediate-type allergic reaction with a sudden acute onset, the spread of the pathological process to various organs and tissues, and a marked impairment of vital body functions are detected. According to statistics, every tenth inhabitant of our planet ever suffered an acute allergic reaction. There are light (localized) manifestations of hypersensitivity in the form of exacerbation of allergic rhinoconjunctivitis and limited urticaria, moderate – with the development of common urticaria, angioedema, laryngospasm, bronchospasm and severe – in the form of anaphylactic shock.
Causes of Allergic Reactions
The development of acute allergic reactions is usually associated with exposure to foreign substances that enter the body with inhaled air (bacterial, pollen, allergens in ambient air and house dust), food, drugs, due to insect bites, when using latex, applied to the skin and mucous membranes of various inorganic and organic substances.
The provocative moments can be exogenous factors: environmental trouble, bad habits, uncontrolled use of medicines and household chemicals. Endogenous risk factors include heredity burdened by allergies, stressful situations, and immune disorders.
Pathogenesis of allergic reactions
The pathological process is most often characterized by the development of an acute allergic reaction of the immediate type. At the same time, IgE-mediated hypersensitivity to the problematic alien substance becomes an antigen. The developing immune reaction proceeds in the presence of three types of cells – macrophages, T-and B-lymphocytes. The class E immunoglobulins synthesized by B cells are located on the surface of target cells (mast cells, basophils).
Re-entry of the allergen into the body leads to the development of an allergic reaction with the activation of target cells and the release of a large number of inflammatory mediators (first of all, histamine, as well as serotonin, cytokines, etc.). Such an immune reaction is usually observed when pollen, food, household allergens, drugs and serums are administered, manifesting as symptoms of pollinosis, atopic dermatitis and bronchial asthma, anaphylactic reactions.
The mechanism of the onset of acute allergic diseases may be due to the formation of cytotoxic, immunocomplex, cell-mediated immune reactions. As a result of pathochemical and pathophysiological changes that develop after sensitization, typical symptoms of acute allergy appear.
Symptoms of allergic reactions
A mild course of acute allergic reactions is most often manifested by symptoms of allergic rhinitis (difficulty breathing through the nose, rhinorrhea, sneezing) and conjunctivitis (itching and swelling of the eyelids, redness of the eyes, photophobia). This may also include the appearance of signs of urticaria in a limited area of the skin (rounded blisters, hyperemia, itching).
With moderate acute allergic reactions, the defeat of the skin becomes more pronounced and is characterized by the development of generalized urticaria with the capture of almost the entire surface of the skin and the appearance of new bubbles within a few days. Often, signs of angioedema, angioedema, and angioedema of the skin, subcutaneous tissue, and mucous membranes are noted.
The pathological process is often localized in the face, affecting the lips and eyelids, sometimes occurs on the hands, feet and scrotum, and can lead to swelling of the larynx and mucous membrane of the gastrointestinal tract. An acute allergic reaction with the development of inflammation of the mucous membrane of the larynx and bronchi can cause severe complications up to death from asphyxiation.
The most severe consequences of the hypersensitivity of the immune system are observed in the event of anaphylactic shock. At the same time, vital organs and body systems are affected – cardiovascular and respiratory, with the occurrence of severe arterial hypotension, collaptoid state and loss of consciousness, as well as respiratory disorders due to laryngeal edema or bronchospasm. Clinical manifestations, as a rule, develop within a few minutes after contact with an allergen, in the absence of qualified emergency care, death often occurs.
Diagnosis of allergic reactions
Diagnosis of acute allergic reactions involves a thorough analysis of anamnestic data (tolerability of drugs and serums, previously suffered allergic diseases), clinical manifestations of allergies (skin lesions, upper respiratory tract, signs of suffocation, fainting, seizures, impaired cardiac activity, etc.).
An examination by an allergologist-immunologist and other specialists is required: a dermatologist, an otolaryngologist, a gastroenterologist, a rheumatologist, etc.
General clinical laboratory tests (blood, urine), biochemical blood analysis are performed, according to indications – determination of rheumatoid factor and antinuclear antibodies, markers of viral hepatitis, the presence of antibodies to other microorganisms, and also instrumental diagnostically necessary in this particular case