Cough in childhood is one of the most common reasons for and symptoms when contacting a pediatric physician. Chronic (lasting over four weeks) wet/productive cough is of particular diagnostic difficulty when it is caused by protracted bacterial bronchitis (PBB). The purpose of this research was to study the etiology, clinical options, X-ray semiotics and comorbid diseases in children with PBB. Materials and methods used: clinical observation and analysis of case histories of 76 children aged starting 4.5 months up to 16 years old with PBB were carried out from Mar. 2017 to Jun. 2022. Research methods: microbiological, radiography and computed tomography (CT) of the chest, bronchoscopy, allergy diagnostics, spirometry. The design of the study was as follows: multicentre, non-comparative, open-label, non-randomized, ambispective pilot study. Results: PBB is more common in boys (57%) aged 3 to 7 y/o (59%) and is rare in infancy (7%). The majority of patients met the clinical definition of PBB (86%) and responded to 2 weeks of antibiotic therapy with amoxicillin/clavulanate (78%). The microbiological diagnosis of PBB was confirmed in 14% of children based on bronchoscopy with microbiological examination of bronchoalveolar lavage (BAL) fluid or sputum examination. The most common pathogens encountered in BAL, sputum and discharge from the nasopharynx, oropharynx are as follows: S. aureus, M. catarrhalis, H. influenzae and S. pneumoniae. The chest X-ray showed bronchitis changes; the chest CT, which was performed in 10 patients, had showed thickening of the bronchial walls. Bronchial dilatation was found in 3 children, bronchiectasis was found in a single patient. Bronchial asthma was comorbid with PBB, occurred in 22% of PBB cases. Conclusion: it is necessary for a pediatric physician to keep PBB in mind as one of the reasons for chronic wet/productive cough in children in order to correctly and timely diagnose the disease and prescribe its adequate treatment.

Neuroendocrine cell hyperplasia of infancy (NEHI) is a rare interstitial lung disease in children. The clinical features of the disease are characterized by tachypnea, moist rales/crepitus, retraction of compliant chest areas and delayed weight gain. The disease is diagnosed using the NEHI clinical scale coupled with the computed tomography of the chest organs. The clinical manifestations of NEHI regress as the child grows, but may persist up to the age of 10 y/o. The purpose of the research was to characterize the course of NEHI including the features of COVID-19 and the impact of passive smoking in children below the age of 8 y/o. Materials and methods: a single-center longitudinal study with follow-up observation of 29 patients with NEHI in January 2012 - December 2022 aged 8 months to 8 years old, 21 of which had COVID-19. Results: 20 of 29 patients with a known follow-up have undergone the long-term oxygen therapy (LTOT) at home lasting from 2 weeks up to 5.5 years (Me 1 year and 2 months; IQR 6 months - 4.5 years). Bronchial asthma was diagnosed in 2. 8 (28%) were diagnosed with atopic dermatitis, 6 (21%) with mental retardation, 3 (10%) with acute urticaria, and 2 (7%) with allergic rhinitis. Gastroesophageal reflux disease (GERD) was diagnosed in 7, all requiring LTOT. The frequency of episodes of respiratory infection was maximum in the first 2 years of life, amounting to 16 episodes per 2 years (Me 7; IQR 4 to 10), and the maximum frequency of hospitalizations during this age period was 5 (Me 2; IQR 1 to 2). Children-passive smokers were diagnosed with malnutrition more often (75%, p=0.449) and required LTOT more often (75%, p=0.694), were more often hospitalized (42%, p=0.422). Despite the possible need for LTOT patients with NEHI had COVID-19 in the form of nasopharyngitis in the majority of cases (89%). Only 8 out of 14 patients had symptoms of NEHI after 5 years of age, and only 1 out of 5 after 7 years. Malnutrition (body mass index for the age<-2) in the first year of life was diagnosed in 13 (45%) children. Malnutrition persisted in 9 out of 24 (37%) by the second year of life, in 5 out of 19 (26%) by the third year, and in 2 out of 14 (14%) by the fourth year of life. Not a single child died. Conclusion: the course of NEHI is characterized by the absence of lethal outcomes, frequent respiratory infections that led to hospitalizations in the first 2 years of life, mild course of COVID-19, regression of clinical symptoms and malnutrition as the child grows, comorbidity with atopic diseases and GERD. The priority should be given to the prevention of passive smoking in children with NEHI.

The review, based on modern literature data and the results of many years of research conducted by the authors, highlights the problem of comorbidity (multimorbidity) in children with bronchial asthma (BA). There is a grouping of concomitant diseases in children with asthma depending on the type of comorbidity (causal, complicated, unspecified, reverse). Based on epidemiological data, observational and cohort studies, systematic reviews and meta-analyses, information on the frequency of BA in children with various comorbid diseases and comorbid diseases in children with BA was summarized. Scientific, theoretical and practical significance of comorbidity in BA, diagnostic and treatment programs in pediatric patients suffering from BA and comorbid diseases are substantiated.

The article provides up-to-date information on epidemiology, etiology, genetics, pathogenesis, pathomorphology, clinical manifestation, X-ray and computed tomography (CT) semiotics, features in childhood, treatment of a rare genetic interstitial lung disease – pulmonary alveolar microlithiasis (PAM). A clinical observation of a child with PAM manifestation, confirmed by lung biopsy in infancy, is presented. The results of X-ray and CT of the patient's chest organs are presented, the unique features of the course of the disease are listed.

The article presents modern information about epidemiology, etiology, pathogenesis, clinical picture, classification by severity, diagnostics and differential diagnostics, treatment and prognosis of viral and relapsing croup in children. Etiological factors, differential diagnostic features and prognosis of croup recidivism in children are considered. The basic diagnostic criteria of alternative diseases with a stridor are given. Croup therapy is characterized on the basis of the Federal Clinical Recommendations and international consensus documents using the principles of evidence-based medicine.

Searching for exact ways and scheme of treatment and supervising asthma patients on long-acting form of b 2-agonist (Formoterol) therapy is still very actual. We studied 31 children (from 7 to 11 years) with moderate non-controled bronchial asthma during 12 weeks. As a basic therapy inhaled corticosteroids-mono or in a combination with Foradyle were used. Corresponding data on Childhood Asthma Control Test, lung function, electrocardiogram, serum potassium and glucose concentrations were monitoring clinically. No adverse reactions were seen. The results obtained for the case of combined therapy with formoterol point out the necessity of more frequent than prescribed observation of the patient state trend, with taking electrocardiography and especially compliance into account.

Results of long-term observation over children of different age with syndrome of bronchial obstruction deal with the various causes are submitted. It is shown, that the group of children with recurrent obstructive bronchitis (ROB) is heterogenic. It includes besides children with infectious ROB, patients with congenital malformations and foreign bodies of tracheobronchial tree, bron chial asthma (BA), broncho-pulmonary dysphasia (BPD). High level of contamination by some membranaceus and endoccllular pathogens in children with ROB and infectious BA is demon strated. The peculiarities of children with BA which predispose them to Mycoplasma pneumoniae infection is discussed. Therapeutic tactics in children with ROB and infectious-dependent BA is offered.