[Definition] Repeated respiratory tract infections refer to the frequent occurrence of upper and lower respiratory tract infections within 1 year, which is beyond the normal range. Judgment conditions] Recurrent respiratory tract infections are categorized into recurrent upper respiratory tract infections and recurrent lower respiratory tract infections according to age, underlying cause, and location, and the latter can be further categorized into recurrent tracheobronchitis and recurrent pneumonia. Table 1 Judgment conditions of recurrent respiratory infections ——— ———- ———- ———- Age (years) Repeated upper respiratory tract infections (times/year) Repeated lower respiratory tract infections (times/year) Repeated tracheobronchitis Repeated pneumonia 0-2 7 3 2 -5 6 2 2 -14 5 2 2 ———————————————————————- —- Note: (1) The interval between infections was at least 7 d. (2) If the number of upper respiratory tract infections is insufficient, the number of upper and lower respiratory tract infections can be added together, but not vice versa. However, if the recurrent infections are sufficiently lower respiratory predominant, it should be defined as recurrent lower respiratory infections. (3) Determination of the number of times must be observed continuously for 1 year. (4) Repeated pneumonia is defined as recurrent pneumonia ≥2 times in 1 year; pneumonia must be confirmed by pulmonary signs and imaging, and signs of pneumonia and imaging changes should disappear completely between two pneumonia diagnoses. Analysis of the etiology of recurrent upper respiratory tract infections and principles of treatment] I. Etiology Infants, toddlers and preschool children with recurrent upper respiratory tract infections are mostly related to improper nursing care, the beginning of the nursery, lack of exercise, relocation of residence, passive inhalation of smoke, environmental pollution, lack of micronutrients or other nutritional components with irrationality, etc.; some of them are related to the nasopharyngeal foci of chronic diseases such as rhinitis, sinusitis, tonsilitis, and other chronic diseases. Rhinitis, sinusitis, enlarged tonsils, adenoid hypertrophy, chronic tonsillitis and so on. Principles of treatment 1. Find the causative factors and treat them accordingly. For chronic nasopharyngeal foci, otorhinolaryngology should be asked to assist in the diagnosis when necessary. As most upper respiratory tract infections are viral infections, antibacterial drugs should not be abused; 2. pay attention to nutrition and dietary habits and enhance the physical aspect of the guidance; 3. appropriate care; 4. develop good hygiene habits, prevention of cross-infections; 5. if necessary, give targeted immunomodulators. [Repeated lower respiratory tract infections etiology analysis and principles of treatment] Repeated tracheobronchitis I. Etiology Mostly due to repeated upper respiratory tract infections improperly treated, so that the disease spreads downward due. Most of them are also caused by pathogenic microorganisms, and a few of them are related to primary immune deficiency and airway malformation. Some children with chronic sinusitis – bronchitis syndrome. Principles of treatment: 1. find the causative factors and give appropriate treatment; 2. pay attention to differentiate from bronchial asthma, wheezing bronchitis, recurrent spasmodic laryngitis, etc.; 3. anti-infective drug treatment needs to be based on the results of the pathogenicity of the test results and the immune state of the body, and the rational application of antibiotics; 4. symptomatic treatment with recurrent pneumonia. For recurrent pneumonia, in addition to considering what kind of pathogenic microorganisms are involved, it is more important to look for the underlying lesions that cause recurrent pneumonia. Primary immunodeficiency diseases: including primary antibody deficiency disease, cellular immunodeficiency disease, combined immunodeficiency disease, complement deficiency disease, phagocytosis defective disease and other primary immunodeficiency diseases. 2. 2. Congenital lung parenchymal and pulmonary vascular development abnormality: children with congenital lung parenchymal development abnormality, such as pulmonary isolation disease, pulmonary cysts, etc., are prone to recurrent pneumonia or chronic pneumonia. Abnormal development of pulmonary blood vessels leads to pulmonary stasis or ischemia, which is easy to be combined with infection and cause recurrent pneumonia. 3. Congenital anomalies of airway development: such as tracheo-bronchial stenosis, tracheo-bronchial softening, tracheo-bronchial bridges, these malformations often cause obstruction of airway secretions and recurrent pneumonia. 4, Congenital heart malformations: various congenital heart diseases, especially the left-to-right shunt type, can cause recurrent pneumonia due to pulmonary stasis. 5, primary ciliary dyskinesia: ciliary structure or dysfunction, due to respiratory mucus clearance obstacles, pathogenic microorganisms retained in the respiratory tract can easily lead to recurrent pneumonia or chronic pneumonia. 6. Cystic fibrosis: in western countries, cystic fibrosis is the most common cause of recurrent pneumonia in children. Oriental yellow race is rare, mainland China and Taiwan has reported individual cases of children, suggesting that children in China may have this disease. 7. Intra-airway obstruction or extra-tubular compression: the most common disease causing intra-airway obstruction in children is bronchial foreign body, followed by tuberculous granuloma and caseous material obstruction, and tracheal and bronchial primary tumors are occasionally seen. The causes of extrinsic compression of airway bones are mostly mediastinal, tracheobronchial lymph node tuberculosis, tumors, vascular malformations. 8. Bronchial dilatation: limited or extensive bronchial dilatation caused by various reasons, due to the obstacle of secretion clearance, pneumonia can occur repeatedly. Repeated aspiration: children with swallowing dysfunction, such as mental retardation, delayed development of cricopharyngeal muscles, neuromuscular diseases, and gastroesophageal reflux, may suffer from recurrent pneumonia due to repeated aspiration. Diseases that need to be differentiated from recurrent pneumonia: tuberculosis, idiopathic pulmonary iron hemosiderosis, asthma, occlusive bronchiolitis with organizing pneumonia (BOOP), eosinophilic pneumonia, allergic alveolitis, idiopathic interstitial pneumonia, and so on. II. Ideas for etiologic analysis The ideas for etiologic analysis are as follows: Detailed history and physical examination Evaluation of chest X-ray L K Repeated single-site pneumonia Repeated multiple-site pneumonia ↓ ↓ ↓ Abnormal bronchial development Immunodeficiency, repeated aspiration Abnormal lung development Abnormal bronchial and lung development, congenital heart disease Extra-airway compression Primary ciliomotor dyskinesia Intra-airway obstruction Extensive bronchiectasis Limitations of bronchiectasis Cystic fibrous Ancillary investigations 1. Otolaryngologic examination: may reveal certain congenital developmental anomalies and foci of acute or chronic infection. 2. 2. Pathogenic microorganism test: Combined multi-pathogen test should be performed to understand the pathogenic microorganisms. 3. Lung CT and airway and vascular reconstruction imaging: can suggest bronchial dilatation, airway stenosis (intraluminal obstruction and extra-tubular compression), airway developmental deformity, lung developmental abnormality, and vascular compression. 4. Immune function measurement: help to find primary and secondary immunodeficiency diseases. Including humoral immunity, cellular immunity; complement, phagocytosis and other tests, should also pay attention to the presence of persistent eczema, thrombocytopenia, ataxia, capillary dilatation and other abnormalities. 5. Bronchoscopy (including rigid, fiber and electronic bronchoscopy): can diagnose foreign body, bronchial dilatation, airway luminal obstruction and extra-tubular compression, airway developmental deformities. 6. Lung function measurement: ventilation function measurement and bronchial excitation test and bronchodilator test when necessary can help to identify metabolic lower respiratory tract diseases; gas exchange function and diffusion function measurement can help to identify certain interstitial lung diseases. 7. Special examination: when primary ciliary dyskinesia is suspected, it is feasible to observe the structure and function of cilia by mucosal biopsy of respiratory tract (nose and bronchus); when cystic fibrosis is suspected, it is feasible to carry out sweat sodium chloride measurement and CFRT examination; when repeated inhalation is suspected, it is feasible to carry out cricopharyngeal muscle function examination or 24-hour pH measurement. Fourth, the principle of treatment 1. Find the cause of the disease, for the treatment of the underlying disease: such as the removal of foreign bodies, surgical resection of tracheobronchopulmonary malformations, the choice of the needle ‘s immunomodulatory agents for the treatment of primary immunodeficiency diseases. 2. Anti-infective treatment: advocate evidence-based empirical selection of anti-infective drugs and targeted medication for pathogen examination and drug sensitivity test results. It is emphasized that antibiotics should not be abused in highly suspected viral infections. 3. Symptomatic treatment: according to different ages and conditions, correctly select Yingchuan expectorant drugs, asthma and cough suppressant drugs, nebulization therapy, pulmonary postural drainage and pulmonary physiotherapy. 4. Reasonable vaccination. V. Tips for serious illness ? Persistent or repeated fever ? Obstructed growth and development, weight loss or emaciation. Continuous or repeated purulent sputum, repeated hemoptysis or hemoptysis. Persistent increased respiration or wheezing, activity intolerance ? Persistent or recurrent pulmonary infiltrates, persistent or recurrent pulmonary rhonchi ? Persistent pulmonary atelectasis or emphysema ? Hypoxemia and/or hypercapnia ? Pestle-like fingers (toes) ? Persistent lung function abnormalities ? Hereditary lung disease in the family