What elements should be included in the cough history for a patient with interstitial lung disease presenting with cough?

Cough History in Interstitial Lung Disease

Essential First Step: Exclude Alternative Causes

Before attributing cough to ILD itself, systematically evaluate and treat common alternative causes—upper airway cough syndrome, asthma, gastroesophageal reflux disease, medication side effects, and pulmonary infections—because more than 50% of ILD patients with cough have these other treatable etiologies. 1, 2

The 2018 CHEST guideline emphasizes that cough in ILD should be considered a diagnosis of exclusion, as common causes of chronic cough occur frequently in the general population and may coexist with ILD. 1

Critical Historical Elements to Obtain

Red-Flag Symptoms Requiring Urgent Investigation

• Hemoptysis – mandates immediate work-up for malignancy, tuberculosis, or pulmonary embolism 1, 3
• Unintentional weight loss – suggests malignancy or tuberculosis 1, 3
• Fever or night sweats – indicates active infection or systemic disease 1, 3
• Recurrent pneumonia – points toward structural lung disease or immunodeficiency 1, 3
• Significant dyspnea at rest or nocturnal dyspnea – may signal severe cardiopulmonary decompensation 1, 3

Medication Review

• ACE inhibitor use – cough typically resolves within a median of 26 days (up to 40 weeks) after discontinuation; this is a common and easily reversible cause 1, 4, 3
• Immunosuppressive therapies – patients on these medications require assessment for pulmonary infections 1

Smoking and Environmental Exposures

• Current smoking status – cough usually improves within 4 weeks after cessation 1, 4, 3
• Occupational exposures – systematic assessment for workplace irritants (dust, fumes, chemicals) is essential, particularly for hypersensitivity pneumonitis 1, 3
• Avocational exposures – pigeon breeding and other hobbies with high antigen exposure can cause hypersensitivity pneumonitis 1

Cough Characteristics and Triggers

• Timing patterns – nocturnal cough suggests asthma or heart failure; post-meal or recumbent cough supports GERD 4, 3
• Common triggers in ILD – body position (74%), physical activity (72%), talking (62%), and lung irritants are frequently reported 5, 6
• Paroxysmal nature – helps differentiate between potential causes 3
• Sputum production – quantify daily volume, as significant sputum usually indicates primary lung pathology 3

Laryngeal Sensations (Cough Hypersensitivity Features)

• Globus sensation (43% of ILD patients) and itch/tickle (42%) are common laryngeal sensations that indicate cough hypersensitivity 5
• The total number of cough-provoking sensations and triggers correlates strongly with quality-of-life impacts (ρ = 0.73) 5

Associated Symptoms by System

• Upper airway symptoms – postnasal drip sensation, frequent throat clearing, nasal congestion, or chronic rhinitis suggest upper airway cough syndrome (accounts for 19–82% of chronic cough) 1, 3
• Lower airway symptoms – wheezing or chest tightness may indicate asthma (15–41% of chronic cough) or eosinophilic bronchitis 1, 3
• Gastrointestinal symptoms – heartburn or acid regurgitation, though GERD-related cough frequently occurs without classic GI symptoms (5–85% of chronic cough) 1, 4, 3

Assessment of ILD Progression

• Temporal association – determine whether cough onset or worsening coincides with disease progression on imaging or pulmonary function tests 7
• Disease severity correlation – cough is more prevalent in patients with more advanced pulmonary fibrosis and lower forced vital capacity 1, 6
• Prognostic significance – in IPF, cough predicts disease progression independent of disease severity 1

Quality-of-Life Impact Assessment

• Use validated tools – visual analog scales or cough-specific quality-of-life questionnaires (e.g., Leicester Cough Questionnaire) to quantify severity 1, 3, 6
• Specific impacts to document:
  • Exhaustion (59% of ILD patients with cough) 5
  • Social embarrassment (70%) 5
  • Urinary incontinence (46% of females) 5
  • Syncope or pre-syncope (12%) 5
  • Impact on everyday life (55%) and all activities (31%) 5
  • Sleep disruption and work absenteeism 4

Past Medical History

• History of asthma, COPD, or bronchiectasis – these commonly present with or are exacerbated by cough 3
• Previous pneumonia, tuberculosis, or pertussis infection 3
• Connective tissue disease – 25% of ILD cases are CTD-associated, and cough is prevalent in scleroderma-related ILD 1, 8

Common Pitfalls to Avoid

• Do not assume ILD is the sole cause – up to 67% of chronic cough patients have multiple concurrent causes requiring combination therapy 1, 4
• Do not rely on cough characteristics alone – timing, character, and associated features lack sufficient sensitivity and specificity to reliably diagnose the underlying cause 4
• Do not assume normal spirometry excludes asthma – cough-variant asthma often presents with normal baseline pulmonary function tests 1, 4
• Do not overlook GERD without GI symptoms – absence of dyspepsia does not exclude gastroesophageal reflux as a cause 4, 3