Symptoms of bronchitis in children

Acute bronchitis (simple) develops in the early days of acute respiratory viral infection (1-3 days of the disease). The main general symptoms of a viral infection (low-grade fever, moderate toxicosis, etc.) are typical, and there are no clinical signs of obstruction. Features of the course of bronchitis depend on the etiology: with the majority of respiratory-viral infections, the condition is normalized starting from 2 days, with adenovirus infection - high temperature figures persist up to 5-8 days.

Acute obstructive bronchitis is accompanied by a syndrome of bronchial obstruction, more often in young children on the 2-3rd day of acute respiratory viral infection, with a second episode - from the first day of acute respiratory infections and develops gradually. Acute obstructive bronchitis occurs against the background of PC viral and parainfluenzal type 3 infections, in 20% of cases - with ARVI of another viral etiology. In older children, the obstructive nature of bronchitis is noted with mycoplasmal and chlamydial etiology.

Acute obliterating bronchiolitis (postinfection obliterating bronchiolitis) is a rare form of bronchiolitis, in which bronchi of small caliber (less than 1 mm in diameter) and arterioles are affected, followed by obliteration of their lumen and narrowing of the branches of the pulmonary, and sometimes bronchial arteries. Generally, it is formed in children of the first 2 years of life, at school age; in adults it develops rarely. Adenoviruses (types 3, 7, 21) play an unfavorable role, but also its development after the influenza, measles, pertussis, legionella and mycoplasma infections.

Obliterating bronchiolitis of another (non-infectious) etiology, for example in the transplanted lung, has an immunopathological genesis.

In early childhood, the formation of postinfection obliterating bronchiolitis occurs at the stage of maximum development of new alveoli from embryonic terminal and respiratory bronchioles. As a result of obliteration of bronchioles, the distal sections of the bronchial tree are permanently damaged, the number of alveoli forming decreases. The volume of the lung decreases, but its airiness is maintained due to collateral ventilation. Air comes through intact airways through the pores of Kohn from the nearby alveoli. This is the basis for the formation of an "air trap" in this disease.

The basis of the morphological pattern is the damage to membranous and respiratory bronchioles, which causes a partial or complete concentric narrowing of the bronchiolar lumen, i. E. Its obliteration. As a rule, the walls of the alveoli and the alveolar courses are not damaged. In the majority of patients, there are no deep destructive changes in the bronchial walls, but some have bronchoectases. Sites of emphysematous bloated alveoli alternate with focal distelectases and small-focal atelectasis. There is a rupture of thin interalveolar septa and the desolation of the capillary network. There is a thickening of the middle shell of segmental, subsegmental and smaller branches of the pulmonary artery. In the venous network, there is fullness.

The outcome of the process is the development of sclerosis sites against the background of the preserved airiness of the pulmonary tissue with the phenomena of hypoperfusion - a picture of the "super-transparent lung".

The course of the disease depends on the varying volume of lung damage. It is possible to develop a one-sided lesion, sometimes almost all of the lung, for example, in the Swaire-James syndrome (Macleod), as well as isolated damage to one lobe or separate segments of both lungs.

Rektsidivirujushchy a bronchitis is defined or determined at repetition of episodes of a bronchitis without an obstruction 2-3 times within 1-2 years on a background ORVI. It is known that children who are often ill with ARI are at risk of developing recurrent bronchitis, which are characterized by a longer course due to the peculiarities of etiopathogenesis and the possible complication of bacterial infection.

The frequency of detection of microorganisms in recurrent bronchitis (from sputum and tracheal aspirate) is about 50%: Str. Pneumoniae - 51%, No. Influenzae - 31%, Moraxella cat. - 2% and other microflora - 16%. In monoculture, bacteria are detected in 85% of children, in associations - in 15%.

The prevalence of recurrent bronchitis is 16.4% per 1000 children. Among the often ill children on appeal, 44.6%, of whom 70-80% have obstructive syndrome.

The high frequency of bronchitis in children on the background of ARVI indicates a possible involvement of the hyperreactivity of the bronchi and allergic component. 80% of children have positive skin tests and elevated IgE. However, sensitization to air allergens is detected only in 15% of children with recurrent bronchitis and in 30% with relapsing obstructive bronchitis (compared to 80% in bronchial asthma). The sensitivity of bronchial receptors is enhanced by viral infection, accompanied by damage to the epithelium of the mucous membrane of the respiratory tract.

Repeated ARI can promote sensitization of the body and create prerequisites for the development of generalized reactions of hypersensitivity with the subsequent formation of obstructive bronchitis and bronchial asthma.

With recurrent bronchitis, there are no violations of humoral immunity, rarely a selective decrease in IgA is observed. The immediate role of chronic foci of infection has not been proven.

The value of connective tissue dysplasia is not excluded, since 90% of children not only have clinical signs (increased skin elasticity and high joint mobility), but also mitral valve prolapse.

Recurrent obstructive bronchitis is bronchitis with recurring episodes of bronchial obstruction on the background of acute respiratory viral infection in young children (usually up to 4 years), but unlike bronchial asthma not having a seizure character and not developing in response to the impact of non-infectious allergens. In most children with allergic reactions, episodes of bronchitis are repeated more often. If these episodes persist for a long time (from 2 to 5 years), the diagnosis "bronchial asthma" is more justified.

The risk group for the development of recurrent obstructive bronchitis includes children with cutaneous manifestations in the first year of life, with high levels of IgE or positive skin tests, with parents with allergic diseases who have had three or more obstructive episodes of paroxysmal nature that occur without temperature. It should be emphasized that recurrent bronchitis is more common in young children and in most of them episodes of obstruction with age cease and children recover.

[1], [2], [3], [4], [5]