How to define chronic coughWhat are the clinical features of chronic coughWhat are the most likely causes of chronic coughHow to examine patients with chronic coughHow to treat patients with chronic cough.
Why we wrote this unit
”Cough is one of the most common reasons for patients to visit their GP, accounting for an estimated 10% of respiratory cases referred to secondary care.1 Chronic cough (lasting more than 8 weeks) usually has physical and psychological effects that impair the patient’s quality of life. It may be caused by a relatively benign condition (e.g. sinusitis) or may be a symptom of a more serious underlying condition. Therefore, you should not underestimate the importance of chronic cough. We have written this article to provide clinicians with a systematic approach to the diagnosis and treatment of chronic cough.”
Key points
A cough can be defined as chronic as long as it lasts longer than 8 weeks. The possible causes of chronic cough are: pulmonary disease, such as asthma extrapulmonary disease, such as GERD idiopathic chronic cough is usually a diagnosis of exclusion You should schedule chest X-rays and spirometry for most patients who do not smoke and are not taking angiotensin-converting enzyme (ACE) inhibitors, and if the chest X-rays are normal, then the most common cause of chronic cough (alone or in combination) is: asthma gastroesophageal reflux disease followed by nasal discharge drip syndrome
Clinical experience
If you take note of the characteristics of the cough and the clinical features associated with it, you can find clues to the diagnosis. It may take months and several consultations to reach a diagnosis and you should refer the patient to a respiratory physician if you are unsure of the diagnosis or if: weight loss and anorexia haemoptysis risk factors for immunosuppression Introduction to night sweats
Cough is a common symptom in primary and secondary care. Acute cough is usually self-limiting and rarely requires medical intervention, whereas chronic cough is a manifestation of many pulmonary and extrapulmonary conditions.
Patients with chronic cough may experience physical, psychological and social difficulties. Because chronic cough can have multiple causes, sometimes deciding on a diagnosis of the underlying disease can be difficult. You may need to undergo some diagnostic treatment and examine the patient several times.
How should you define cough?
There is no universally agreed definition of cough. Guidelines consider a cough to be an explosive movement with force, usually by opening a closed vocal door and making a characteristic sound.
It is further classified according to the duration of the symptoms. Typically, a cough lasting less than 3 weeks is considered acute.1 Acute cough is usually caused by a viral infection of the upper respiratory tract. Chronic cough can be defined as lasting longer than 8 weeks.1 Coughs that fall between these time periods are difficult to classify.
How common is chronic cough?
Studies show that chronic cough is seen in 10-20% of the general population.1 It seems to be more common in women and in people who are overweight.
What are the physical and psychological effects of chronic cough?
Chronic cough has a wide range of physical and psychological effects that can impair people’s quality of life. Data from some studies point to a reduced quality of life for patients with COPD compared to those with advanced COPD. A recent cross-sectional survey of at least one week’s duration found that 7% of the general population had a cough severe enough to interfere with their daily activities. Questionnaires (such as the Leicester Cough Questionnaire) have been developed to assess the physical, psychological and social health effects of chronic cough.
Physical effects
The physical effects of cough include
Chest musculoskeletal pain Sleep disturbances (both for the patient and their partner) Headaches Hoarseness Throat pain Urinary incontinence Vomiting Syncopal episodes. Psychological effects
The psychological effects of cough include.
irritability fatigue self-consciousness and embarrassment fear of serious underlying illness (especially cancer) avoidance of public places work-related difficulties personal relationship tension. What are the causes of chronic cough? Common causes
The most common causes (singly or in combination) of normal chest X-rays in patients who do not smoke and are not taking angiotensin-converting enzyme (ACE) inhibitors are 5.
asthma gastroesophageal reflux disease post nasal discharge down drip syndrome asthma
Cough can be one of the main features of asthma. It is usually associated with changes in peak expiratory flow rate and intermittent airflow obstruction. In cough variant asthma, the prominence of wheezing and shortness of breath symptoms is reduced, cough may be the only symptom, and airway hyperresponsiveness is usually present.
Eosinophilic bronchitis can cause cough, characterized by eosinophils greater than 3% in sputum specimens, without peak expiratory flow rate changes and airway hyperresponsiveness.6 Some authors consider eosinophilic bronchitis to be a type of asthma.
Gastroesophageal reflux disease
GERD can be present without significant GI symptoms and may be a cause of chronic cough. The mechanism by which GERD causes cough is unknown, but it has been shown to be associated with an increased sensitivity of the cough reflex and a small amount of aspiration.
According to recommendations published in the British National Formulary, the following medications may worsen the symptoms of GERD
Steroids theophylline bisphosphonates non-steroidal anti-inflammatory drugs calcium channel antagonists. Posterior nasal tract secretion hypodrip syndrome
Patients with posterior nasal tract hypersecretion syndrome may notice secretions dripping down into the oropharynx and they need to clear their throat frequently.
Other causes
Cough may be a major symptom of a variety of respiratory diseases, which may be due to underlying pulmonary pathology. Examples of primary lung diseases include.
chronic obstructive airway disease lung cancer bronchiectasis tuberculosis mediastinal tumors pulmonary fibrosis foreign body inhalation airway irritants such as smoking, dust and smoke chronic aspiration, for example secondary to neuromuscular dysfunction.
Examples of non-primary respiratory diseases that can cause cough include pulmonary edema and pertussis.
Cough and ACE inhibitors
ACE inhibitor-associated cough is a species effect, not dose-dependent, seen in 5-10% of the drug-exposed population. Once the drug is discontinued, the cough disappears within a month. You should consider starting an alternative antihypertensive drug, such as an angiotensin II receptor antagonist.
Idiopathic chronic cough
Idiopathic chronic cough is usually a diagnosis of exclusion, but it may account for up to 20% of patients in cough specialist clinics. These patients are usually middle-aged women.
Highlights in the history
You may find some diagnostic clues in some patients’ histories that point to the underlying disease. You should ask the following questions.
Characteristics of the cough – a definitive diagnosis cannot be reliably indicated, but certain associations may provide clues to the diagnosis
Table: Characteristics and possible causes of cough
Clinical features
Interpretation of clinical features
Sudden onset
Inhalation of a foreign body may be associated with sudden onset of cough.
Cough with sputum
Chronic cough with coughing sputum is more supportive of the diagnosis of primary lung disease.
Diet-related
A cough that occurs after a meal or a cough that is aggravated by eating is suggestive of GERD.
Vocalization-related
In patients with GERD, talking, laughing or singing may cause coughing. This is because the diaphragm does not close the lower esophageal sphincter.
”Goose” or “barking” sounds
A “goose” or “barking” sound may indicate a psychogenic or habitual cough, especially in cases of nocturnal relief.
History of smoking – chronic cough is more common in smokers and is generally considered to have a dose-effect relationship, with the severity of symptoms correlating with the amount of smoking Past history – childhood asthma or eczema may indicate asthma, and childhood pneumonia or whooping cough may indicate bronchiectasis Dust, chemical or allergen exposure – Occupational experience and asking about possible environmental irritants in the home (including pets) can identify triggers for symptoms Gastrointestinal symptoms – if the patient complains of dyspepsia, GERD may be the cause of chronic cough Medications – ask if the patient uses ACE inhibitors Other respiratory Symptoms – wheezing, shortness of breath, hemoptysis, coughing up purulent sputum, and chest pain all suggest cardiopulmonary underlying disease Upper respiratory symptoms – nasal congestion, dyspnea, discharge, facial fullness, and frequent throat clearing all suggest an upper respiratory tract infection as the cause of chronic cough. Physical examination
Physical examination is usually unremarkable. Signs such as pestle and mortar or swollen lymph nodes may indicate that the underlying disease is primary lung or heart disease.
You should also examine the patient’s ears, nose and throat for an upper respiratory cause of the cough. A persistent cough may be caused by irritation of the external ear canal, excessive ear wax, or middle ear disease that irritates the Arnold nerve (vagus nerve branch).
Laboratory and ancillary tests in the primary care setting
Guidelines suggest that chest X-rays and spirometry are mandatory for patients with chronic cough.
Chest X-ray
Chest X-rays are a useful first-line adjunct in the diagnosis of many lung diseases, especially lung cancer in current or former smokers. A study of general respiratory clinics found that 31% of chest X-rays ordered for persistent cough were abnormal or diagnostic.
Spirometry
Spirometry is increasingly used in primary care settings. Spirometry suggests obstructive (first second expiratory volume (FEV1)/exertional spirometry (FVC) <0.7, FEV1 <80% of expected value). In patients with a history of smoking, spirometry is suggestive of obstructive ventilation disorders and the etiology of chronic cough may be chronic obstructive pulmonary disease.
In patients with chronic cough, spirometry suggests restrictive (FEV1/FVC ≥0.7) and the etiology may be interstitial lung disease, respiratory muscle weakness or morbid obesity. Spirometry results are often normal in patients with asthma, so a normal result does not exclude the diagnosis.
Specific laboratory and ancillary tests
Depending on the clinical condition, you may consider referring patients presenting with atypical signs or symptoms to a respiratory clinic for specific laboratory and ancillary tests.
Bronchial provocation test (usually with acetylcholine or histamine)
This test can be helpful for patients in whom you are unsure whether a diagnosis of asthma is possible. It assesses the presence of airway hyperresponsiveness (usually characterized by a 20% decrease in FEV1 after administration of bronchoconstrictors).
Bronchoscopy
The chest physician may order a bronchoscopy if the patient may be aspirating a foreign body or has unexplained hemoptysis. Bronchoscopy is generally less likely to be diagnostic in patients with chronic cough, but it can be used to rule out vocal cord disease (e.g., vocal cord paralysis) and can be used to reassure some patients.
Fiberoptic laryngoscopy
If symptoms persist or if clinical features of upper respiratory tract disease are present, the chest physician may order a fiberoptic laryngoscopy. This clinical examination uses an easily bendable fiberoptic laryngoscope that allows for a quick and easy way to examine the larynx and vocal cords, which appear inflamed and edematous in GERD.