Allergic bronchitis is an inflammation of the walls of the bronchi, which occurs due to hyperergic immune reactions. The disease is provoked by various allergens: household, plant, infectious, chemical products. The disease is manifested by paroxysmal cough, difficulty breathing, respiratory failure phenomena. The diagnostic plan includes chest radiography, spirometry, laboratory tests of blood and sputum. Treatment involves the exclusion of contact with allergens, drug therapy with the use of bronchodilators, corticosteroids, antihistamines.
J40 Bronchitis, unspecified acute or chronic
Allergic bronchitis is a common problem of childhood. The disease usually becomes a component of the “allergic march” in children, and if timely treatment is not carried out, it often transforms into bronchial asthma. The defeat of the bronchopulmonary system with a characteristic obstructive component is typical for preschoolers and schoolchildren, at an earlier age, pathology in children is rare. The frequency of the disease is constantly increasing against the background of increasing sensitization of the population, which explains the high relevance of the problem and its treatment.
Reasons of allergic bronchitis
For the formation of allergic bronchitis, a provoking factor is required — an endogenous or exogenous allergen, in response to which a characteristic immune hyperergic reaction is triggered in children. In early childhood, food allergens are a frequent trigger, as the child grows up, household dust, plant factors, and intestinal helminths come to the fore. All causes of bronchitis can be divided into the following groups:
- Inhalation. This category includes household triggers (dust, mites), epidermal antigens (pet hair and secrets, epidermis particles, human hair), pollen allergens. The development of allergic bronchitis is possible when inhaling the vapors of paint and varnish products, strongly smelling household chemicals.
- Enteral. Nutritional factors are typical for an early age, they cause the first manifestations of damage to the respiratory system in children. Most often, the pathology is provoked by eggs, cow’s milk, nuts, citrus fruits. Some medications belong to enteral triggers.
- Infectious. This includes helminthiasis characteristic of children (ascarids, whipworms, pinworms), the negative effects of protozoa, mold fungi. Allergic inflammation of the bronchi often occurs as a complication of staphylococcal, streptococcal infection, some viral processes with their incorrect treatment.
- Endo-allergens. This category includes all types of allergens that are formed in the body under the influence of physical harmful factors, with ischemia of organs and tissues, changes in the structure of macroorganism proteins during infectious diseases.
In addition to the action of allergens as the direct cause of the disease, predisposing factors are required for the development of pathology. More than 50% of children have a hereditary predisposition to atopic diseases, often a detailed assessment of the anamnesis reveals the pathological course of pregnancy and childbirth.
In addition, in recent decades there has been a trend towards an increase in the number of allergoses, which is associated with the antigenic load on the child when using vaccines, serums, medicines, the widespread influence of industrial factors, folk, not traditional methods of treatment.
The development of respiratory allergosis proceeds according to the first (reagin) type of allergic reaction, according to the classification of Jell and Coombs. It is manifested by the increased production of class E immunoglobulins, and the main components of the inflammatory reaction in the bronchial wall are basophils, mast cells, eosinophils. A specific feature of this process is the speed of the appearance of symptoms after contact exposure to allergens.
There are 3 consecutive phases in the mechanism of formation of immune inflammation. The first stage is immunological. It begins with the nonspecific interaction of the allergen with macrophages, as a result of which the production of specific antibodies is activated. B-lymphocytes begin to synthesize IgE, which circulate in the bloodstream, settle on mast cells and smooth muscle elements.
At the second stage, a pathochemical reaction begins. In its development, the main role is played by mast cells (basophils), in the cytoplasm of which there are granules of mediators. The process of degranulation begins: 20-30 minutes after interaction with the allergen, first—order mediators are released — histamine, tryptase, neutrophil chemotaxis factor, and 2-6 hours later, second-order mediators – leukotrienes, thromboxanes, prostaglandins.
Damage to the bronchi occurs at the third stage – during the pathophysiological phase of the immune reaction. Under the influence of inflammatory mediators, capillaropathy develops, cellular infiltrates form, and edematous syndrome occurs. At this stage, clinical symptoms are noticeable in children. there is hyperreactivity of the bronchi, narrowness of the airways, so the obstructive component is rapidly increasing.
Symptoms of allergic bronchitis
The main sign of the disease is a painful paroxysmal cough. Seizures occur with the same frequency day and night, and may increase with repeated interaction with the trigger. When coughing, a small amount of viscous mucosa or cloudy sputum is released. Often, 2-3 days before the appearance of cough paroxysms, the child complains of a sore throat, watery discharge from the nose.
For bronchial lesions occurring with obstruction phenomena, wheezing is typical. These sounds are so pronounced that parents notice them even at a distance. The “whistling” in the respiratory tract increases with a cough attack. Also, children’s breathing increases to 25-30 or more per minute, which indicates the ineffectiveness of lung ventilation, the appearance of shortness of breath, progressive tissue hypoxia.
A distinctive feature of allergic bronchitis is a moderately pronounced intoxication syndrome. Most children have a normal or subfebrile body temperature, and additional symptoms include increased fatigue, headaches, and decreased appetite. Due to frequent painful coughing, patients become irritable, night coughing attacks disrupt sleep.
In addition to respiratory symptoms, other signs of allergies may appear. Skin rashes are often formed: large blisters, small red nodules, puffiness and redness of the skin. The rash is accompanied by intense skin itching. If the allergen penetrates through the gastrointestinal tract, digestive disorders are observed: abdominal pain and cramps, nausea, diarrhea.
With allergic bronchitis, children may develop respiratory insufficiency (DN) due to bronchial obstruction phenomena. At first, there is a compensated variant, the treatment of which is not difficult, in the absence of timely help, the DN goes into a decompensated phase, accompanied by arterial hypoxemia, hypercapnia. This condition is one of the causes of multiple organ failure.
With a prolonged course of allergic bronchitis, there is a negative effect of cough on the body as a whole. Due to a decrease in the suction action of the chest, blood flow to the heart is disrupted, blood pressure increases. In combination with increased venous pressure, small hemorrhages appear in the conjunctiva of the eyes. Prolonged dry cough leads to neurosis, reduces the quality of life.
Allergic bronchitis in children can occur as the first attack of bronchial asthma, which at the initial stage, as a rule, has an erased clinical picture, resembles a typical cold. Alarming symptoms include bouts of unproductive cough, which are accompanied by difficulty exhaling. After the end of the paroxysm, lethargy, drowsiness, apathy are bothered.
Diagnostics of allergic bronchitis
During the physical examination of the child by a pediatrician, dry wheezing, bronchovesicular breathing with prolonged exhalation (expiratory sighing), box sound with percussion over the lungs are determined. The detection of shortness of breath, wheezing breathing and painful coughing attacks makes it possible to suspect allergies as the etiology of bronchitis. To confirm the diagnosis and the choice of treatment, the following diagnostic methods are prescribed:
- Radiography of OGK. In acute allergic bronchitis, the changes are represented by a bilateral strengthening of the pulmonary pattern, expansion and destruction of the roots of the lungs. With frequent recurrent inflammation of the bronchi, there is an increase in the transparency of the pulmonary fields, expansion of intercostal spaces, flattening of the dome of the diaphragm.
- Functional diagnostics. In children over 5 years of age, the spirometry technique is used, with the help of which the volume exhalation rate, the Tiffno index, and the functional vital capacity of the lungs are estimated. Peak flowmetry is performed for rapid assessment of the peak exhalation rate. According to the diagnostic results, obstructive and restrictive disorders are differentiated.
- Sputum tests. Microscopic examination of sputum reveals an increased number of eosinophils, the appearance of characteristic spirals and crystals indicates the development of bronchial asthma. To exclude the infectious nature of bronchitis, a bacteriological analysis of sputum, a study for tuberculosis is used.
- Blood tests. In a general clinical study, eosinophilia, an increase in ESR are determined, in a biochemical analysis — an increase in acute phase parameters. A specific manifestation of allergic bronchitis is an increase in the level of immunoglobulin E (from 1.5 IU /ml under the age of one year, up to 200 IU/ml for 10-16-year-old patients and 100 IU/ml for adults). In the morning of patients, the total IdE does not increase, but only the content of specific IDEs to individual allergens increases.
- Skin allergy tests. After achieving remission of allergic bronchitis, a comprehensive diagnosis is performed to clarify the cause-dependent factors. To identify clinically significant allergens and the degree of sensitization, scarification tests are recommended.
Treatment of allergic bronchitis
To quickly stop an acute attack and prevent its recurrence, it is necessary to change the child’s lifestyle, which allows to limit contact with provoking factors to the maximum. If possible, non-specific factors irritating the bronchi are excluded: cold air, dustiness of premises, pungent odors of plants and cosmetics. Parents are strictly forbidden to smoke with a child.
Given the high prevalence of food allergies in children, the treatment regimen necessarily includes a sparing diet. Substances that can trigger an attack are excluded. These include preservatives with metabisulfite and sulfur oxide, many food dyes, and sodium glutamate. In order not to provoke pseudoallergia, it is recommended to reduce the consumption of products containing histamine.
Adequate hydration is important in the treatment: copious drinking of water, fruit drinks, unsweetened tea. To reduce bronchial irritation, the room temperature is maintained at 20-22 degrees, humidity at 50-60%. To stimulate the discharge of sputum from the bronchial tree, drainage massage, breathing exercises, physical therapy are prescribed.
The therapy of allergic bronchitis is selected by a pediatrician together with a pediatric pulmonologist and an allergist-immunologist. Treatment includes local remedies to expand the bronchial lumen, reduce the intensity of coughing attacks, as well as systemic medications designed to relieve specific inflammation in the tissues of the respiratory tract. For therapeutic purposes are used:
Bronchodilators. To eliminate the phenomena of bronchial obstruction, short-acting bronchodilators are indicated, which are administered using an inhaler or nebulizer. In rare cases, oral derivatives of methylxanthines are used in the treatment.
Mucolytics. Ambroxol and acetylcysteine preparations are used to dilute viscous sputum in children. It is possible to prescribe for the treatment of reflex action agents, phytopreparations. Inhalations that moisturize the bronchial mucosa and promote effective expectoration of sputum give a good effect.
Antihistamines. Medications are indicated for the rapid elimination of a hyperimmune reaction, reducing the release of allergy mediators. Treatment can be supplemented with cell membrane stabilizers and other modern antiallergic agents.
Anti-inflammatory drugs. To reduce the swelling of the bronchi and eliminate other symptoms of the disease, funds are selected from the group of nonsteroidal anti-inflammatory drugs. In severe cases, treatment is supplemented with inhaled or systemic corticosteroids.
In acute insufficiency, a standard complex of intensive treatment is carried out: restoration of the patency of the respiratory tract, artificial oxygenation with the introduction of nasal catheters or the imposition of a facial mask, and in severe cases artificial ventilation of the lungs is performed. The treatment regimen also includes improving the drainage function of the bronchi: aspiration of secretions through an endobronchoscope, ultrasound inhalations, chest massage.
Prognosis and prevention
An integrated approach to the treatment of allergic bronchitis with the exception of provoking factors allows you to quickly stop the symptoms, restore the full function of the respiratory system. However, pathology often has a chronic recurrent course, can transform and manifest itself in the form of bronchial asthma, so the prognosis for life is favorable, and for recovery is doubtful.
Prevention of bronchitis consists in the maximum possible avoidance of allergenic effects, timely therapy of acute respiratory infections. To increase the nonspecific resistance of the body, a balanced fortified diet, strengthening of immunity, and a rational regime of motor activity are required. To prevent the recurrence of allergic bronchitis, dispensary observation is carried out.