Exacerbation of bronchial asthma and allergic rhinitis in the cold season What we need to know

Bronchial asthma and allergic rhinitis are chronic diseases that are quite common in the population. The incidence of asthma is 4.3% worldwide and this rate is constantly increasing, especially in industrialized countries. The frequency of allergic rhinitis is much higher and exceeds 37% in European countries. Several studies have established a close correlation between bronchial asthma and allergic rhinitis.

Pathophysiology of bronchial asthma

Asthma is a chronic lung disease characterized by:

• Reversible narrowing of the diameter of the bronchus, as a result of dysfunction and hyperactivity of the smooth muscles of the bronchus
• Chronic (prolonged) inflammation in the mucous layer of the bronchus

The existence of various phenotypes of asthma depends on:

• on the age of development of the disease
• on the severity of symptoms
• on the presence of exacerbations
• on the presence of concomitant diseases

Therefore, depending on the mechanism of inflammation, there are several subtypes of asthma, such as: in both forms - allergic and non-allergic eosinophilic asthma, there is inflammation, although the mechanism is different.

• Allergic eosinophilic asthma is the main subtype.
• Neutrophilic asthma - in this case, mucosal damage occurs with the participation of neutrophils, against the background of the inflammatory process, without eosinophils. This is related to the presence of cigarette smoke, air pollutants or microorganisms. Long-term treatment with corticosteroids may also provoke neutrophilic inflammation of the airways.
• Asthma - with a low number of granulocytes - in this form, mucosal inflammation is not expressed.

From a clinical point of view, a prolonged acute asthmatic condition may cause structural changes in the mucous and submucosal tissues and muscle layer of the airways. This leads to thickening of the mucous membrane and vascularization (formation of new vascular plexuses, which contributes to the existence of the inflammatory process).

The narrowing of the airways developed as a result of structural changes worsens the ventilation of the lungs and causes a decrease in the concentration of oxygen in the arterial blood.

Effects of cold on the respiratory system and results in bronchial asthma

There is an opinion that cold aggravates dysfunctional processes in patients with chronic diseases of the respiratory system. The reason for this is low temperature and humidity, which causes damage to the epithelium of the respiratory tract, narrowing of the airways and bronchial hyperactivity.

According to available data, people with bronchial asthma, without proper control, are more prone to exacerbation of respiratory symptoms in the cold season.

When the air temperature drops rapidly and the body cannot adapt to the environment, a number of changes develop in the respiratory system, which creates the risk of chronic obstructive pulmonary diseases and asthma exacerbation.

Inhalation of cold air causes bronchoconstriction and narrowing of the lumen of the bronchi, which is especially noticeable for patients with asthma. Mucous structures of the upper part of the respiratory system are especially sensitive to cold air. Within the framework of various clinical studies, the influence of cold dry air on the respiratory tract has been studied both in allergic and non-allergic rhinitis and asthma. Research data confirm that low air temperature is an important risk factor for exacerbation of allergic rhinitis and asthma.

Long-term exposure to cold air on the respiratory tract causes anatomical changes in the respiratory system, namely:

• increasing the number of granulocytes in the bronchoalveolar fluid
• Destruction of ciliary epithelium with a protective function
• thickening of the submucous connective tissue layer - lamina propria - and inflammatory changes in it
• hyperactivity of the mucous layer and suffocation of the upper respiratory tract

 Viral respiratory infections

One of the frequent causes of aggravation of the condition is viral infections, which are especially relevant in the cold season. The most common are human rhinoviruses of type A and С, respiratory syncytial viruses, parainfluenza virus, adenoviruses and others. The peak of hospitalization due to asthma complications coincides with the season of respiratory viral diseases in September-December period.

Allergy and antiviral immunity deficiency

Allergic inflammatory processes reduce resistance to viral infections. The production of type I interferons is an important antiviral response in response to respiratory viral infections.

Available data confirm that virus-induced interferon production in plasma cells, mononuclear cells and bronchial epithelial cells is significantly reduced in allergic asthma. Occupancy of the membrane surface of these cells by IgE immunoglobulins inhibits the production of α-interferons, which increases the possibility of asthma exacerbations and viral infections.

bacterial infections

Bacterial infections increase the production of mucus in the respiratory tract, inhibit the processes of mucus evacuation (due to the dysfunction of ciliated epithelial cells) and contribute to the formation of inflammatory processes in the lower respiratory tract. The direct relationship between bacterial infections and asthma exacerbations is not clear, however, as a result of viral processes, immune system deficiency causes Weakening of antibacterial protection and changes in local microflora.

Influence of environmental allergens

Environmental allergens have the ability to provoke asthma. Activation of mast cells by allergens leads to the generation of histamine, prostaglandin D2 and leukotrienes, and as a result narrowing of the muscular layer of the respiratory system, increasing the permeability of blood vessels, increasing the secretion of mucus and strengthening the inflammatory process.

Other contributing factors

Pollutants such as tobacco smoke, ozone, sulfur dioxide, nitrogen dioxide, fuel emissions, occupational pollutant exposure, and others increase the possibility of developing inflammation in the respiratory system and exacerbation of asthma.

Diagnosis

Exacerbation of already diagnosed asthma sometimes requires additional tests and treatment.

A high IgE titer in the blood usually indicates an allergic origin of asthma. To determine the atopic status, immunological studies are needed - Fadiatop and Fadiatop Infant.

A high level of eosinophils indicates exacerbation of allergic inflammation and confirms the diagnostics of eosinophilic asthma.

A high level of serum eosinophilic cationic protein is an indicator of the inflammatory process and reflects the severity of the aergic process or eosinophilic activity better than IgE. It is directly related to the severity of the disease or atopy.

At the beginning of the treatment in the acute stage of the disease, it is important to determine the functional state of the kidneys and lungs, for monitoring of which functional samples are provided.

During an exacerbation of bronchial asthma, it is sometimes necessary to have an X-ray examination of the lungs, CT, bronchoscopy and spirometry.

Prevention of complications

Patient education, regular monitoring of symptoms and lung function, as well as precipitating factors, management of comorbidities, and adequate pharmacotherapy are important components of enabling asthma and allergic rhinitis management.

Asthma exacerbations can be reduced, but not always prevented, despite a controlled treatment plan.

Laboratory "Synevo" offers diagnostic tests and allergy panels:

We also offer liver and kidney function tests and profiles:

The time for issuing research results is not absolute, it can change taking into account various factors

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Source:

https://www.synevo.ro/simptomatologie-astm-bronsic-in-sezonul-rece/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5950727/

n.manjaparashvili@synevo.ge