Cough which lasts for more than 8 weeks in duration.
A heightened cough reflex has been suggested as the primary abnormality (1).
According to epidemiological surveys of the general population, persistent cough has been reported in 16% of the population in south-east England
- it is commoner in females and obese people
- responsible for 10% of respiratory referrals to secondary care (1)
Most patients present with a dry or minimally productive cough but in some, there can be disabling symptoms associated with significant impairment in quality of life:
- physical - complains of musculoskeletal chest pains, sleep disturbance, and hoarse voice
- psychological - depressive symptoms and worry about serious underlying diseases such as cancer and tuberculosis
- social - difficulty in relationships, avoidance of public places, and disruption of employment (1)
A detailed patient history should be obtained in order to identify any initiating event. Inquire about:
- angiotensin-converting enzyme (ACE) inhibitor
- smoking - which appears to be dose-related with cough changing in character when smoking is discontinued
- characteristics of cough
- sudden onset may be associated with foreign body aspiration
- sputum production suggests primary pulmonary pathology
- cough which abates overnight may be due to reflux
- coughing which wakes the patient up may be due to asthma, infection, or heart failure
- a typical "honking" or "barking" quality, disappears with sleep and is not awakened by cough - may be psychogenic or habitual cough
- clinical features of an underlying disease - COPD, asthma, bronchiectasis, lung cancer
- occupation - which might reveal workplace sensitisers
- dust/chemical exposure at home
- cough on eating and postprandially, when talking on the telephone, laughing, or singing - may indicate reflux cough
- family history - chronic cough may be familial
Investigations carried out in primary care include:
- chest radiographs - should be done in all patients with chronic cough and those with acute cough demonstrating atypical symptoms
- spirometry - should be performed in all patients with chronic cough (1)
Reference:
- Morice AH et al. Recommendations for the management of cough in adults. Thorax. 2006;61 Suppl 1:i1-24