Introduction
Cough is the explosive expiration that clears the tracheo-bronchial tree of secretions and foreign particles or noxious gaseous materials.
It is a defensive reflex reaction. It comes to medical attention only when it becomes troublesome, affects life style and/or when there is concern about its cause.
Clinical features
Cough may be:
- Acute or chronic
- Seasonal
- Associated with breathlessness and or wheezing
- Productive of sputum: note colour,
smell; haemoptysis - Associated with fever
- Associated with chest pain: note location and character of pain
- Associated with risk factors, e.g. cigarette smoking
- Associated with the use of drugs for other illnesses
- Associated with other constitutional symptoms
Differential diagnoses
Triggers of cough may rise from the upper or lower airways, or lung parenchyma
Upper airways:
- Inhaled irritants: dust, fumes, smoke
- Upper airways secretion
- Gastric reflux
Lower airways:
- Inflammation
- Viral bronchitis
- Bronchiectaesis
- Bacterial infection
- Bronchial asthma
- Endobronchial tuberculosis
- Bronchial infiltration/compression
- Parenchymallung disease
- Pneumonia
- Lung abscess
- Interstitial or endobronchial oedema due to heart disease
- Drugs:
- ACE inhibitors
Investigations
- Macroscopic and microscopic examination of sputum
- Sputum culture
- Exclude tuberculosis if cough is chronic
- Sputum cytology for malignant cells
- Chest radiograph where indicated
- HIV screen if history and clinical features are suggestive
Treatment objectives
- Identify and treat the underlying cause(s)
- Abolish cough
Non-drug measures
- Adequate rehydration to prevent inspissation
- Encourage expectoration forbproductivebcough
- Do not use antitussives unless cough is dry, unproductive and distressing
Drug treatment
- Appropriate antibiotics for bacterial infections
- Identify causative/precipitating factors and treated accordingly e.g. CCF, asthma; allergies
Cough suppressants:
- for dry, unproductive cough
- Codeine cough linctus: Adult: 5-10 mL 3-4 times daily
- Dextromethorphan (if codeine is contraindicated) 30 mg tds
Codeine is not recommended in children
Notable adverse drug reactions, caution
- Codeine cough linctus: sedation, constipation