Causes of respiratory allergies

With respiratory allergy occurs mainly inhalation sensitization by various exogenous allergens.

Household allergens occupy a leading place in the formation of respiratory allergies.

Home dust is multicomponent in composition. It includes allergens of house dust mites, epidermal, fungal, bacterial, chemical allergens.

A child with a respiratory allergy may have a hypersensitivity to both the complex allergen of household dust and its individual components.

The main part of house dust is allergens of the insect fauna of the dwelling: chitinous membrane, secrets and excreta of house dust mites (D. Pteronyssimus, D. Farinae, D. Microceras, Euroglyphus mainae), cockroaches (Blattella germanica, Blattella orintalis). Many ticks are in carpets, drapery fabrics, bedding, soft toys and furniture. The best conditions for the reproduction of ticks are the temperature of 22-26 ° C and the relative humidity of more than 55%.

Tick-sensitization in patients with respiratory allergies is characterized by year-round exacerbations with increasing frequency in the spring-autumn period, with deterioration at night. In case of allergy to cockroaches, exacerbations occur more often during the day.

The main sources of epidermal allergy are wool, down, feather, dandruff, excrement, saliva of various animals (cats, dogs, guinea pigs, hamsters and other rodents, rabbits, horses, sheep, etc.). The most aggressive allergen of a cat's fur is feb 1; dogs - Cad 2, are in saliva. A high level of these allergens persists in the house for several years after the removal of the animal.

Exacerbations with sensitization to epidermal allergens year-round, with an increase in the cold season, when the patient is more in the room.

Pollen allergens.

The high incidence of fungal sensitization in allergic diseases of the respiratory tract is due to the widespread prevalence of mold fungi in nature. Their spores are smaller in size than pollen and are spread over long distances. A particularly high concentration of fungal aeroallergens in regions with high humidity.

External sources of fungal allergens are haystacks, fallen leaves, hothouse farms, poultry and livestock farms, microbiological, pharmaceutical and food industries.

In the development of fungal sensitization in children, unsatisfactory living conditions are of great importance: mold on walls in apartments with leaking roof, standing water in basements. A high concentration of mold fungi is also noted in the dust, in the soil of pots with indoor plants, in air conditioners and humidifiers, in cages with poultry and animals.

With sensitization to the fungi of the genus Alternaria and Cladosporium, the exacerbations become more frequent during the formation of the spores - from March to the first frosts. Fungi of the genus Aspergillus and Mucor are very common in damp areas, where conditions for abundant spore formation are created, which leads to year-round exacerbations.

Some groups of drugs can induce aggravation of allergic diseases of the respiratory tract. Among them, the leading place is occupied by antibiotics of penicillin series (rarely macrolides), sulfonamides, vitamins, aspirin and other nonsteroidal anti-inflammatory drugs. The aggravation of the disease can be associated not only with the use of these drugs, but also with environmental contamination by pharmaceutical enterprises.

Food allergens play a lesser role in the etiology of respiratory allergy than inhalation, but their role in the formation and flow of both small forms of allergies (allergic rhinitis, relapsing laryngitis), and bronchial asthma, exogenous allergic alveolitis is well known.

For allergic diseases of the respiratory tract, the age-related evolution of the sensitization spectrum is typical: food allergy in young children, inhalation household in 3-5 years, and by the school age pollen sensitization is added. However, household sensitization occurs in children under one year, which is an unfavorable prognostic sign for the development of bronchial asthma.

Pathogenesis of respiratory allergies. Along with edema of the mucous membrane and hypersecretion, the stimulation of afferent nerve endings by biologically active mediators causes sneezing, coughing. The acute phase of the atopic reaction lasts 30-40 minutes. The delayed reaction (the reaction of the late phase) leads to infiltration by the cells of the mucous membrane of the upper respiratory tract, which leads to the development of allergic inflammation in the mucous membrane, which is now regarded as the main pathogenetic mechanism of development of both small forms of respiratory allergosis and bronchial asthma. Chronic allergic inflammation promotes the formation of airway hyperreactivity. Hyperreactivity of the mucous membrane of the upper respiratory tract is clinically manifested by sneezing, rhinorrhea, nasal congestion, coughing in response to the effects of non-antigenic factors (cold air, physical stress, harsh odors, etc.).

[1], [2], [3], [4]