Cough Classification and Management

Initial Assessment and Classification

The American College of Chest Physicians recommends classifying cough as acute (<3 weeks), subacute (3-8 weeks), or chronic (>8 weeks) to determine the diagnostic and therapeutic approach 1, 2
Discontinue ACE inhibitors immediately if present, as they are a common reversible cause of cough 1, 2, 3
Counsel smokers on cessation, as 90-94% of smokers experience cough resolution within the first year of quitting 3
Assess for signs of life-threatening disease, such as pneumonia, pulmonary embolism, or systemic illness requiring urgent intervention 1, 2
Evaluate respiratory distress indicators, including markedly elevated respiratory rate, intercostal retractions, cyanosis, or altered mental status 2
Identify risk factors for complications, such as comorbidities, frailty, immunosuppression, or impaired cough clearance 2

Obtain a chest radiograph if pneumonia is suspected based on tachypnea, tachycardia, dyspnea, or abnormal lung findings 2
Perform spirometry as part of the basic evaluation for chronic cough, although its utility is not clearly established in this context 2

For acute cough (<3 weeks), use a first-generation antihistamine/decongestant combination plus naproxen for common cold, and a short course of systemic corticosteroids for acute exacerbation of chronic bronchitis 2
For subacute cough (3-8 weeks), determine if postinfectious or non-infectious, and manage accordingly, considering upper airway cough syndrome, transient bronchial hyperresponsiveness, asthma, or pertussis 1, 4
For chronic cough (>8 weeks), use a sequential and additive treatment approach targeting the three most common causes, which frequently coexist 1, 2

For upper airway cough syndrome, use an oral first-generation antihistamine/decongestant combination, and add a topical corticosteroid if prominent upper airway symptoms are present 1, 2, 4, 5
For asthma, treat with inhaled bronchodilators and inhaled corticosteroids if spirometry shows reversible airflow obstruction, and consider a bronchoprovocation challenge or empiric trial of inhaled corticosteroids and bronchodilators if spirometry is normal 1, 2, 4, 5
For non-asthmatic eosinophilic bronchitis, perform an induced sputum test for eosinophils, and use empiric treatment with inhaled corticosteroids if testing is unavailable 1, 4, 5
For gastroesophageal reflux disease, initiate empiric treatment for patients with typical reflux symptoms before performing esophageal testing 5

Pursue advanced testing, such as high-resolution CT scan or bronchoscopic evaluation, if cough persists after 4-6 weeks of empiric treatment for the top diagnoses 2, 6
Consider referral to a specialist cough clinic when diagnosis remains unclear 5

Do not rely on cough characteristics alone, as they have little diagnostic value 1, 2
Do not treat only one cause, as multiple factors often contribute simultaneously, requiring additive therapy 1, 2
Do not label as idiopathic until thorough assessment at a specialist clinic excludes uncommon causes 5, 6
Do not use routine cough suppressants when cough clearance is important 5

In immunocompromised patients, use the same initial algorithm but expand the differential diagnosis based on immune defect type and severity 2, 6
In HIV patients with CD4+ <200 cells/μL, suspect Pneumocystis pneumonia, tuberculosis, and opportunistic infections 2, 6
In high-prevalence areas, obtain sputum smears, cultures for acid-fast bacilli, and chest radiograph to evaluate for tuberculosis 6