Management of Subacute Cough

Immediate Assessment and Red Flags

The American College of Chest Physicians recommends screening for life-threatening conditions, including hemoptysis, vital sign abnormalities, asymmetrical lung sounds, systemic symptoms, and smoker status over 45 years with new or changed cough, and if present, to order a chest X-ray immediately and consider pneumonia, tuberculosis, pulmonary embolism, heart failure, or malignancy 1, 3
Red flags that demand urgent investigation include hemoptysis, vital sign abnormalities such as heart rate ≥100 bpm, respiratory rate ≥24 breaths/min, temperature ≥38°C, asymmetrical lung sounds or focal consolidation, systemic symptoms like fever, unintentional weight loss, night sweats, and smoker status over 45 years with new or changed cough 1, 3

If a preceding respiratory infection is present, it is likely a postinfectious cough, with common causes including postinfectious inflammation, upper airway cough syndrome, asthma exacerbation, and nonasthmatic eosinophilic bronchitis 2, 5
The American College of Chest Physicians recommends evaluating for pertussis if paroxysmal coughing episodes, post-tussive vomiting, inspiratory whooping sound, or recent exposure to confirmed pertussis case are present 7

Suspect pertussis immediately if paroxysmal coughing episodes, post-tussive vomiting, inspiratory whooping sound, or recent exposure to confirmed pertussis case are present, and start treatment with azithromycin without waiting for laboratory confirmation 7

Inhaled ipratropium is the first-line treatment for postinfectious cough, and if ipratropium fails or severe symptoms are present, consider dextromethorphan 60 mg or prednisone 30-40 mg/day for a short period 5, 7
First-generation antihistamine plus decongestant has been shown to decrease cough severity and hasten resolution in patients with upper airway symptoms 6

Check if the patient is taking an ACE inhibitor, as it can cause persistent cough, and stop the medication immediately if present, with a median time to cough resolution after stopping of 26 days 3, 4

In TB-endemic areas or high-risk populations, consider tuberculosis even with normal chest X-ray, and obtain a chest radiograph, collect sputum smears and cultures for acid-fast bacilli, and consider TB but not to the exclusion of more common causes 1, 3

Routinely assess cough severity or quality of life using a validated tool before and after treatment, and schedule follow-up in 4-6 weeks, with a full chronic cough workup if cough persists beyond 8 weeks 1, 2