Why is a chronic cough easy to ignore?
A cough can be chronic even if there is no abnormality on an X-ray chest film
Coughs are usually divided into 3 categories according to their duration: acute cough, subacute cough and chronic cough. Acute cough is shorter than 3 weeks, subacute cough is 3-8 weeks, and chronic cough is longer than 8 weeks (the above classification is for adults, while children with more than 4 weeks are considered to have chronic cough). Chronic cough has many causes and is usually divided into two categories based on the presence or absence of abnormalities on chest x-ray. One category is those with obvious lesions on chest X-ray, such as pneumonia, tuberculosis, bronchopulmonary cancer, etc. The other category is those with no obvious abnormalities on chest X-ray and cough as the main or only symptom, which is usually referred to as unexplained cough.
Cough has a defensive function of removing foreign bodies from the respiratory tract; however, cough is also a sign of disease. Chronic cough can cause many hazards, including cardiovascular, gastrointestinal, genitourinary, neurological, skeletal-muscular, and respiratory complications. First, prolonged and frequent coughing can cause damage to the airway mucosa, and this damage to the airway mucosa can in turn aggravate the cough. Second, repeated violent coughing can cause a very high intrapulmonary pressure, which can cause or exacerbate the formation of emphysema and even the occurrence of pneumothorax. Again, increased intrapulmonary pressure can lead to a decrease in the amount of blood returned to the heart, which in turn can lead to a decrease in cardiac output and insufficient blood supply to the brain, causing clinical symptoms of cough syncope.
Why is there a high incidence of chronic cough?
Chronic cough is associated with other systemic diseases
Common causes of chronic cough include: cough variant asthma (CVA), upper airway cough syndrome (UACS), eosinophilic bronchitis (EB) and gastroesophageal reflux cough (GERC). These etiologies account for 70% to 95% of the causes of chronic cough in respiratory medicine outpatient clinics. Other etiologies are less common but are widely involved and are associated not only with respiratory diseases but also with diseases of other systems.
UACS is a syndrome in which nasal diseases cause secretions to back up behind the nose and throat, which directly or indirectly stimulate cough receptors, resulting in a cough as the main manifestation.UACS is one of the most common causes of chronic cough. In addition to nasal diseases, UACS is often associated with diseases of the throat, such as allergic or non-allergic pharyngitis, laryngitis, pharyngeal neoplasia, and chronic tonsillitis.
CVA is a specific type of asthma in which cough is the only or main clinical manifestation. It has no obvious signs or symptoms such as wheezing and shortness of breath, but has airway hyperresponsiveness. The main manifestation is an irritating dry cough. patients with CVA usually have a more violent cough, and nocturnal cough is an important feature. Cold, cold air, dust and fumes can easily trigger or aggravate the cough.
EB is a non-asthmatic bronchitis characterized by airway eosinophil infiltration and negative airway hyperresponsiveness. The main manifestation is a chronic cough that responds well to glucocorticoid therapy. The main symptom is a chronic irritating cough with dry or little white mucus sputum, which may be present during the day or at night. Some patients are sensitive to fumes, dust, odors or cold air, which are often triggering factors for coughing. Patients do not have symptoms such as shortness of breath or dyspnea.
GERC is a clinical syndrome caused by reflux of gastric acid and other gastric contents into the esophagus, resulting in a cough as a prominent manifestation. It belongs to a specific type of GERD and is a common cause of chronic cough. Typical reflux symptoms manifest as heartburn (burning sensation behind the sternum), acid reflux, and belching. Some GERD-induced coughs are accompanied by typical reflux symptoms, but many patients have cough as the only manifestation. The cough mostly occurs in a low or lying position, with a dry cough or a small amount of white mucous sputum. Eating acidic, oily foods tends to trigger or aggravate the cough.
Why is it not treated with antibiotics?
Chronic cough is not related to infection!
Most chronic coughs are not associated with infections and do not need to be treated with antibacterial drugs. Use oral or intravenous glucocorticoids with caution when the cause of the cough is unknown or when infection cannot be excluded.
Empirical treatment of chronic cough means that in case of uncertainty about the etiological diagnosis, appropriate therapeutic measures are given according to the condition and the possible diagnosis, and the diagnosis is established or excluded by the response to treatment. Empirical treatment should be based on the following principles.
Treatment is first directed at the common causes of chronic cough. The results of domestic and international studies show that the common causes of chronic cough are CVA, UACS, EB and GERC.
The possible etiology of chronic cough is inferred from the medical history. If the patient’s main manifestation is irritating cough at night, the patient can be treated as CVA; if the cough is accompanied by significant acid reflux, belching and heartburn, the patient is considered to be treated as GERC; if the cough secondary to a cold persists, the patient can be treated as post-infectious cough; if the cough is accompanied by runny nose, nasal congestion, nasal itching and frequent throat clearing, the patient is first treated as UACS.
Those with cough, coughing up pus sputum or a runny nose can be treated with antibiotics. Most chronic cough etiologies are related to infectious etiologies and empirical treatment should avoid abuse of antibiotics.
Empirical treatment is often 1 to 2 weeks for UACS, CVA, and EB, and at least 2 to 4 weeks for GERC. Oral glucocorticoids are usually administered for no more than 1 week. If empirical treatment is effective, continue with the standardized treatment protocol for the appropriate cough etiology.
Those whose empirical treatment is ineffective should promptly go to a qualified hospital for relevant investigations to clarify the etiology. Follow up closely to avoid missing early bronchial malignancies, tuberculosis and other lung diseases.
Warm tips.
Because of a persistent cough, patients may move around to several hospitals and have the same items checked repeatedly. In fact, chronic cough is a disease involving multiple systems throughout the body, and fixing the same doctor or the same hospital may be more helpful in the observation and differential diagnosis of the disease.