Causes of chronic pneumonia
Last reviewed: 16.05.2018
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Chronic pneumonia is formed under the influence of various factors:
- adverse outcome of acute pneumonia;
- atelectasis of various origins, including congenital;
- aspiration of foreign bodies;
- chronic food aspiration;
- congenital defects of the tracheobronchial tree;
- congenital microdefects of bronchial structures;
- immunodeficiency;
- ciliary dysfunction, etc.
The most common pathogens that support the chronic inflammatory process in the altered bronchi are Haemophilus influenzae, pneumococcus, hemolytic streptococcus, and gram-negative opportunistic flora.
The incidence of primary chronic pneumonia in children is progressively decreasing. This is mainly due to the improvement in the quality of diagnostics of acute pneumonia and the use of active antibiotics in their treatment, improved diagnostics of congenital defects and hereditary diseases, in which the chronic bronchopulmonary process is secondary to the underlying disease.
Pathogenesis of chronic pneumonia. The leading role in pathogenesis is played by impaired bronchial patency and atelectasis. In the lesion, against the background of hypoxia, there is a violation of lymph and blood circulation, trophism, innervation; a decrease in the enzymatic activity of cellular elements with the expression of proliferative processes.
The morphological basis of chronic pneumonia is limited pneumosclerosis with deformation and expansion of the bronchi in its zone. The predominance of one or another component of irreversible changes in the bronchopulmonary system determines a wide range of clinical and radiological manifestations in this disease: from local asymptomatic pneumofibrosis to severe bronchiectasis.
In local (limited) pneumosclerosis, sclerosis affects the distal parts of the bronchi and peribronchial tissues.
Bronchiectatic disease is a variant of chronic pneumonia, the main morphological substrate of which is regional expansion of the bronchi, mainly in the lower segments of the lungs, accompanied by a suppurative process.
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