I. What is chronic cough?
Chronic cough is a cough that lasts longer than 4 weeks and has no significant abnormalities on X-ray chest. Acute cough is a cough that is less than 4 weeks straight.
II. Common causes of chronic cough (normal chest X-ray) in children.
1. Cough variant asthma.
2. Upper airway cough syndrome.
3. Post-infectious cough.
4. Gastroesophageal reflux cough.
5, Foreign body aspiration.
6. Psychogenic cough.
(I) 1. Cough variant asthma.
Cough variant asthma is a specific type of asthma with cough as the only or main symptom. Persistent cough >4 weeks, often at night and/or in the early morning, cough aggravated by exercise, exposure to cold air, no clinical signs of infection or ineffective after longer antibiotic treatment. Diagnostic treatment with bronchodilators may result in significant relief of cough symptoms. Pulmonary ventilation is normal and bronchial excitation tests suggest airway hyperresponsiveness. These children often have a history of allergic disease including drug allergy, as well as a positive family history of allergic disease, and a positive allergen test may aid in the diagnosis.
(I) 2. Treatment and prognosis of cough variant asthma.
Avoid exposure to allergens. Adopt a treatment regimen similar to that of typical asthma. Treatment with inhaled hormones should last no less than 6-8 weeks. Consider additional leukotriene receptor antagonist therapy if airway eosinophilia is demonstrated. Most children with cough symptoms disappear after treatment, but some cough returns after discontinuation of the drug and 30% will transform into typical asthma.
(ii) 1. 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. A previous diagnosis of postnasal drip syndrome, meaning that inflammatory nasal secretions back up into the pharynx, or even the trachea, through the postnasal orifice and stimulate its cough receptors to produce a chronic cough.
Chronic cough with or without sputum is worse in the early morning or when the body odor changes, and is often accompanied by nasal congestion, runny nose, dry throat with foreign body sensation, repeated clearing of the throat, and a feeling of mucus adhesion to the posterior pharyngeal wall. On examination, there may be pressure pain in the sinus area, yellowish-white discharge from the opening of the sinus, obvious hyperplasia of follicles in the posterior pharyngeal wall, cobblestone-like, and sometimes mucus-like attachment to the posterior pharyngeal wall can be seen. Targeted treatment such as antihistamines and leukotriene receptor antagonists, and nasal glucocorticoids are effective. If the sinusitis is caused by sinusitis, the corresponding changes can be seen on sinus X-ray or CT film.
(ii) 2. Treatment of upper airway cough syndrome.
For upper airway cough syndrome caused by allergic rhinitis, antihistamines + decongestants are the most commonly used initial treatment, with an onset of action taking more than 1 week. Leukotriene receptor antagonists may be added for those who do not respond well to antihistamines. Avoid contact with allergens as much as possible, and desensitize if necessary. Nasal glucocorticosteroids are the most effective drugs for the control of allergic rhinitis and are generally advocated to be gradually downgraded to the minimum required dose and maintained for a period of time after the symptoms are controlled. Longer-term antibiotic therapy remains the primary treatment for chronic sinusitis in children today. The course of treatment may take 4-6 weeks or even longer, and is generally required until symptoms have resolved for at least 1 week. Nasal irrigation and nasal inhalation of decongestants may be a good adjunct. Sinus endoscopic surgery and adenoidectomy are available. Rhinitis and sinusitis are often combined in children and are called rhinosinusitis. Most sinusitis is preceded by allergic rhinitis, which results in poor drainage due to inflammation of the sinus openings and leads to bacterial secondary infection, thus often requiring additional anti-allergy treatment and, if necessary, nasal inhalation hormone therapy.
(iii) 1. Post-infectious cough.
The integrity of the airway epithelium is disrupted due to infection, the submucosal nerve endings are exposed, and sensitivity to various stimuli, including cold air and smoke, is increased. Airway inflammation persists and temporary airway hyperreactivity exists As the airway mucosal epithelium is repaired and inflammation subsides, airway reactivity returns to normal and the cough is naturally relieved; this process mostly takes 1-3 weeks and 10% may still have symptoms leading to chronic cough after 4 weeks.
With a recent clear history of respiratory infection, an irritating dry cough or a small amount of white mucous sputum, a chest X-ray with no abnormalities, and normal pulmonary ventilation, the cough is usually self-limiting If the cough lasts longer than 8 weeks, other diagnoses should be considered.
Certain pathogenic infections can cause chronic cough, such as Mycobacterium pertussis, Mycobacterium tuberculosis, Mycoplasma pneumoniae, Chlamydia pneumoniae, and cytomegalic inclusion virus. In recent years, cough caused by Mycoplasma pneumoniae has been found to be more common. It often presents as a paroxysmal spasmodic dry cough, heavy at night, and the pulmonary signs are often not obvious.
(iii) 2. Treatment of post-infectious cough.
The main treatment is pathogen-specific, supplemented by appropriate symptomatic treatment. The majority of children can be relieved over time without special treatment. For those with obvious and persistent symptoms, the use of anticholinergic drugs or corticosteroids for nebulized inhalation or antihistamines or leukotriene receptor antagonists can be considered. In some children, it is difficult to distinguish infectious from post-infectious cough and appropriate antibacterial drugs may be tried. For those caused by Mycoplasma pneumoniae and Chlamydia infection, macrolide antibiotics such as azithromycin should be applied.
(iv) 1. Gastroesophageal reflux cough.
Gastroesophageal reflux is a physiological phenomenon in infancy. The incidence of gastroesophageal reflux in healthy children is 40%-65%, with a peak between 1 and 4 months and mostly natural remission at 1 year of age. GERD becomes a disease when it causes symptoms and/or is accompanied by gastroesophageal dysfunction, and the prevalence of GERD in children is about 15%. GERD can be accompanied by a chronic cough.
The cough is paroxysmal, sometimes severe, and occurs mostly at night. Most of the symptoms appear after eating and drinking, and feeding is difficult. Some children have upper abdominal or subxiphoid discomfort, burning sensation behind the sternum, chest pain, and sore throat. In addition to causing coughing, infants may also suffer from asphyxia, bradycardia, and bowing of the back This may lead to growth arrest or retardation in children.
(iv) 2. Treatment of GERD cough.
For milder symptoms, treatment is achieved by changing the diet and body position. Drug therapy requires a long duration and sufficient intensity, usually taking effect in 2-4 weeks. Cough without GI symptoms requires 2-3 months to be effective, and treatment is continued for 3 months after cough termination: omeprazole, ranitidine, morpholine. Surgical treatment: medication is ineffective for 3 months or relapses after discontinuation of medication.
(v) 1. Foreign body inhalation.
Cough is the most common symptom after airway foreign body aspiration, which is an important cause of chronic cough in children aged 1-3 years. 70% of children with airway foreign body aspiration present with cough, and other symptoms include decreased breath sounds, wheezing, and choking. The cough usually presents as a paroxysmal, violent choking cough, or it can simply present as a chronic cough with obstructive emphysema or pulmonary atelectasis. In general, the onset of the cough is characterized by a sudden choking cough without fever, but over time, secondary infection can develop, causing fever, etc. Once the foreign body enters the area below the small bronchus, there can be no cough, which is called entering the “silent zone”.
(E) 2. Treatment of foreign body inhalation.
The cough caused by foreign body aspiration can be clarified by lung CT and airway 3D reconstruction techniques, or by fiberoptic bronchoscopy. The first step in treatment is to remove the foreign body, and in addition, anti-infective treatment is required for combined infections. In most children, the cough is quickly relieved after the foreign body is removed. However, infection secondary to foreign body inhalation can also cause post-infectious cough and requires appropriate treatment.
(vi) Psychogenic cough and treatment.
It is more common in older children. The cough is predominantly daytime and disappears when the child focuses on something or rests at night. It is often accompanied by anxiety symptoms. No organic disease is present. Tic disorders must be excluded. The cough improves significantly with behavioral intervention or psychotherapy.
Third, should you take cough medicine for chronic cough.
The use of cough suppressants is not advocated in chronic cough before the cause is clearly identified. Codeine is contraindicated in the treatment of all types of cough. Finasteride may mislead parents that its application will reduce the child’s cries while ignoring the adverse effects: irritability, hallucinations, abnormal muscle tone, and even apnea.
Chronic cough with phlegm should be treated as an expectorant. It is not possible to simply stop the cough, which may aggravate or lead to airway obstruction. Commonly used drugs are: Mucosolvan (Ambroxol hydrochloride), Aesop (Guaifenesin glycerol ether), Genoton (Myrtle oil), and herbal expectorants.
Fourth, should you take antibiotics for chronic cough.
Cough is divided into infectious cough and non-infectious cough. Antibiotics cannot cure cough associated with allergic diseases and cough caused by digestive tract diseases. Antibiotics have no cough suppressant effect. Therefore, antibiotics are only needed if the cough is considered to be caused by an infection.