Chronic cough in children is a common problem in pediatrics, accounting for a significant proportion of pediatric outpatient visits, and is one of the more difficult problems to solve. In view of this, we would like to talk about chronic cough in children and the advantages of Chinese medicine treatment, with reference to the relevant literature.
I. Definition of chronic cough in children
A cough that lasts for 4 weeks is called a chronic cough.
II. Causes of chronic cough in children
1. Idiopathic cough
This refers to a cough accompanied by other signs or symptoms that suggest an atopic cause, i.e., the cough is one of the symptoms of these clearly diagnosed diseases. For example, cough accompanied by expiratory dyspnea, prolonged expiratory phase on auscultation or croup often indicates intrathoracic airway pathology such as tracheobronchitis, asthma, congenital abnormal airway development (e.g. tracheobronchial softening), etc.; accompanied by shortness of breath, hypoxia or cyanosis indicates pulmonary inflammation; accompanied by growth disorders and pestle-like fingers (toes) often indicates severe chronic lung disease and congenital heart disease, etc.; accompanied by Pus sputum suggests pulmonary inflammation, bronchiectasis, etc.; hemoptysis suggests severe pulmonary infection, pulmonary vascular disease, pulmonary ferritinosis or bronchiectasis, etc.
2. Non-specific cough
This refers to chronic cough in which cough is the main or only manifestation and no abnormalities are seen on chest X-ray. This is the main type of chronic cough in clinical practice, also known as “chronic cough in the narrow sense”. The causes of non-specific cough in children are age-specific and require careful systematic evaluation, thorough history taking and physical examination.
(1) Respiratory infections and post-infectious cough: Respiratory infections caused by many pathogenic microorganisms such as Mycobacterium pertussis, Mycobacterium tuberculosis, viruses (especially respiratory syncytial virus, parainfluenza virus, cytomegalic inclusion virus), Mycoplasma pneumoniae, and Chlamydia are common causes of chronic cough in children, mostly in preschool children as young as 5 years old.
(2) Acute respiratory infections: post-infectious cough can be considered when cough symptoms persist for more than 4 weeks. The mechanism may be disruption of airway epithelial integrity and/or squamous metaplasia of ciliated columnar epithelial cells due to infection and/or persistent airway inflammation with temporary airway hyperresponsiveness.
The clinical features and diagnostic clues of post-infectious cough are.
(1) A recent history of definite respiratory tract infection.
(2) Cough that is irritatingly dry or accompanied by a small amount of white sputum.
(3) No abnormalities on chest radiographs.
(4) Normal pulmonary ventilation function.
(5) Cough is usually self-limiting.
(6) Other causes of chronic cough are excluded. If the cough lasts longer than 8 weeks, other diagnoses should be considered.
3. Cough variant asthma
Cough variant asthma is one of the common causes of chronic cough in children, especially in preschool and school-age children.
Clinical features and diagnostic clues are.
(1) persistent cough for 4 weeks, often with episodes at night and/or early in the morning, aggravated by exercise, exposure to cold air, and no clinical signs of infection or ineffective after longer antibiotic treatment.
(2) Diagnostic treatment with bronchodilators results in significant relief of cough symptoms.
(3) Normal pulmonary ventilation with bronchial excitation tests suggesting airway hyperresponsiveness.
(4) History of allergic disease including drug allergy, and a positive family history of allergic disease. A positive allergen test may assist in the diagnosis.
(5) Excluding chronic cough caused by other diseases.
4. Upper airway cough syndrome
Various rhinitis (allergic and non-allergic), sinusitis, chronic pharyngitis, chronic tonsillitis, nasal polyps, adenoid hypertrophy, and other upper airway diseases can cause chronic cough, which was previously diagnosed as postnasal drip (flow) syndrome, meaning cough caused by nasal secretions flowing backwards through the postnasal orifice toward the pharynx. It is recommended that the name upper airway cough syndrome be used instead of postnasal drip (flow) syndrome.
The clinical features and diagnostic clues of upper airway cough syndrome are.
(1) chronic cough with or without coughing sputum, which is worse in the early morning or when the position is changed, often accompanied by nasal congestion, runny nose, dry throat with foreign body sensation, repeated clearing of the throat, and a feeling of mucus attachment to the posterior pharyngeal wall; a few children complain of headache, dizziness, and low-grade fever.
(2) examination of the sinus area may have pressure pain, the sinus open day can be yellowish white secretion outflow, the posterior pharyngeal wall follicle obvious hyperplasia, cobblestone-like, sometimes can be seen in the posterior pharyngeal wall mucus-like attachment.
(3) targeted treatment such as antihistamines and leukotriene receptor antagonists, nasal glucocorticoids are effective.
(4) sinusitis, sinus x-ray or CT film can be seen corresponding changes.
5. Gastroesophageal reflux cough
Gastroesophageal reflux (GER) is a physiological phenomenon in infancy and early childhood. The incidence of GER in healthy infants is 40%, peaking at 1-4 months of age and mostly resolving spontaneously at 1 year of age. GERD becomes a disease when it causes symptoms and/or is accompanied by gastroesophageal dysfunction, and the prevalence of GER in children is about 15%.
The clinical features and diagnostic clues of GERD cough are.
(1) paroxysmal cough, sometimes severe, occurring mostly at night.
(2) Symptoms mostly appear after eating and drinking and feeding difficulties. (2) Some children have epigastric or subxiphoid discomfort, retrosternal burning, chest pain, and sore throat.
(3) In addition to causing coughing, the infant may also suffer from asphyxia, bradycardia, and an arched back.
(4) It can lead to stagnant or delayed growth of the affected child.
6.Eosinophilic bronchitis
Eosinophilic bronchitis is considered to be an important cause of chronic cough in adults, but its incidence in children is unclear.
The clinical features and diagnostic clues of eosinophilic bronchitis are.
(1) chronic irritant cough.
(2) Normal chest x-ray.
(3) Normal pulmonary ventilation without airway hyperresponsiveness.
(4) Relative percentage of eosinophils in the sputum.
(5) Effective oral or inhaled glucocorticoid therapy.
7.Congenital respiratory tract disease
It is mainly seen in infants and children, especially within 1 year of age. They include congenital tracheoesophageal fistula, congenital vascular malformation compressing the airway, laryngotracheobronchial softening and/or stenosis, bronchopulmonary cysts, ciliary dyskinesia, and mediastinal tumors. It presents as a persistent cough, and the mechanism may be related to tracheal softening obstructing the discharge of secretions and inflammatory damage to the terminal bronchi. This condition is often misdiagnosed as asthma.
8. Psychogenic cough
Psychogenic cough in children can only be diagnosed when tic disorders are excluded and the cough improves after behavioral interventions or psychotherapy; cough features are only suggestive of psychogenic cough and do not have a diagnostic role.
The clinical features and diagnostic clues of psychogenic cough are.
(1) Prevalence in older children.
(2) A predominantly daytime cough that disappears when focused on an event or when resting at night.
(3) It is often accompanied by symptoms of anxiety.
(4) No organic disease and other causes of chronic cough are excluded.
9. Other causes
(1) Foreign body aspiration: coughing is the most common symptom after aspiration of foreign bodies in the airway, and foreign body aspiration is an important cause of chronic cough in children, especially in children aged 1 to 3 years. Studies have found that some patients with airway foreign body aspiration present with cough and other symptoms such as decreased breath sounds, wheezing, and history of asphyxia. The cough usually presents as a paroxysmal violent choking cough, or it may only present as a chronic cough with obstructive emphysema or pulmonary atelectasis, and once the foreign body enters the area below the small bronchus, there can be no cough, which is called the “silent zone”.
(2) Drug-induced cough: Angiotensin-converting enzyme inhibitors are less commonly used in children, and some children with renal hypertension may have cough induced by the use of drugs such as captopril. The mechanism may be related to the secretion of bradykinin, prostaglandins, and substance P. ACEI-induced cough usually manifests as a chronic persistent dry cough that is aggravated at night or when lying down, and can be significantly reduced or even disappeared after 3-7 days of drug withdrawal. p-adrenergic receptor blockers, such as tretinoin, can cause bronchial hyperresponsiveness, so they may also lead to drug-induced cough.
(3) Otogenic cough: This group of people has vagal ear branches. When lesions occur in the middle ear, stimulation of the vagus nerve can cause a chronic cough. Otogenic cough is a rare cause of chronic cough in children.
C. Chronic cough in children has advantages in Chinese medicine treatment
Asthma and chronic cough are common respiratory diseases in children, and their prevalence has been on the rise worldwide in recent years, seriously endangering the physical and mental health of children and causing mental and economic burdens for many families of affected children. Therefore, it has attracted more and more attention from the medical community. At present, Western medicine treats children’s asthma mainly with bronchodilators combined with glucocorticoids or combined with anti-allergic drugs, which are effective in the near future, but the cough is likely to recur after stopping the drugs. Due to the existence of unique Chinese medicine resources in China, there is a great prospect of using Chinese medicine to treat asthma and chronic cough in children. The treatment of chronic cough in children using TCM has obvious advantages and has achieved relatively good results.