What additional history, physical examination findings, and diagnostic investigations are needed to evaluate a patient with a 2‑3‑week onset of intermittent productive cough with blood‑streaked sputum after a viral upper respiratory infection, worsened in the mornings and by supine position, cold air, laughter, and post‑exercise, who denies fever, pleuritic pain, dyspnea at rest, tachycardia, leg swelling, smoking/vaping, has no personal history of asthma, eczema, or chronic respiratory disease, is not taking any medications, and has a family history of asthma in a younger sibling?

Missing Elements in the Clinical Evaluation

Critical History Components

You must obtain a detailed smoking and vaping exposure history, including secondhand exposure at home, work, or social settings, as this is a dominant cause of chronic cough and must be definitively excluded. 1

Additional History to Obtain

• Medication history: Specifically ask about any ACE inhibitor use (even if patient denies "prescription medications," probe for blood pressure medications from other providers), as ACE inhibitors are a common cause of chronic cough 1

• Occupational and environmental exposures: Ask about workplace irritants, dust, chemicals, fumes, or cold air exposure at work, as these can perpetuate cough 1

• Pertussis-specific symptoms: Explicitly ask about paroxysmal coughing fits, post-tussive vomiting, or inspiratory "whoop" sound, as pertussis must be excluded when cough lasts ≥2 weeks with these features 2, 3

• Upper airway symptoms: Ask about frequent throat clearing, sensation of post-nasal drip, nasal congestion, or sinus pressure, even if mild, as "silent" upper airway cough syndrome (UACS) can present with cough alone 1, 2

• Gastroesophageal symptoms: Ask about heartburn, regurgitation, sour taste, throat burning, or hoarseness, recognizing that "silent GERD" commonly causes cough without typical GI symptoms 1, 2

• Quantify hemoptysis: Document the exact volume and frequency of blood-streaked sputum (you have "small streaks" on 2-3 mornings, which is helpful but needs precise quantification in teaspoons/tablespoons) 2

• Constitutional symptoms: Explicitly document absence of fever, night sweats, unintentional weight loss, as these are red flags requiring immediate chest X-ray 2, 4

• Atopic history: You have family history of asthma in sibling, but ask about patient's history of allergic rhinitis, food allergies, or drug allergies, as atopy increases likelihood of cough-variant asthma 1

Physical Examination Findings Needed

Perform a focused examination looking for specific diagnostic clues that differentiate between the dominant causes of subacute cough: UACS, asthma, GERD, and postinfectious cough. 1, 2

Upper Airway Examination

• Nasal examination: Look for pale, boggy turbinates (allergic rhinitis), erythematous turbinates (infectious rhinitis), or nasal polyps 1
• Oropharyngeal examination: Look for cobblestoning of posterior pharynx (classic for post-nasal drip/UACS), tonsillar hypertrophy, or pharyngeal erythema 1

Pulmonary Examination

• Auscultation during forced expiration: Listen specifically during forced exhalation and after coughing, as wheezes may only be audible with these maneuvers in cough-variant asthma 1
• Document presence or absence of crackles: Crackles suggest pneumonia, bronchiectasis, or interstitial lung disease and mandate chest X-ray 2
• Percussion: Dullness suggests consolidation or effusion 2

Other Systems

• Digital clubbing: Presence suggests bronchiectasis, interstitial lung disease, or malignancy 2
• Lymphadenopathy: Cervical or supraclavicular nodes raise concern for tuberculosis or malignancy 1

Diagnostic Investigations Required

Order a chest X-ray immediately because hemoptysis—even blood-streaked sputum—is a red flag that mandates radiographic evaluation to exclude pneumonia, tuberculosis, bronchiectasis, or malignancy. 2, 4

First-Line Investigations

• Chest radiograph (PA and lateral): This is mandatory given the hemoptysis, and will exclude pneumonia, tuberculosis, mass lesions, and other structural abnormalities 2, 4

• Spirometry with bronchodilator response: Perform to detect reversible airway obstruction characteristic of asthma, as cough-variant asthma accounts for 24-32% of chronic cough cases and may present without wheezing 1, 2

Second-Line Investigations (if initial workup normal)

• Bronchoprovocation challenge (methacholine or exercise challenge): If spirometry is normal but asthma is suspected, bronchial hyperresponsiveness testing can diagnose cough-variant asthma 1, 2

• Induced sputum for eosinophil count: A sputum eosinophil count >3% suggests either cough-variant asthma or non-asthmatic eosinophilic bronchitis (NAEB), which accounts for 13-33% of chronic cough and responds to inhaled corticosteroids 1, 2

• Pertussis serology or PCR: Given the 4-week timeline since URI and the paroxysmal nature (waking at night, triggered by laughter), pertussis must be excluded with serologic testing or nasopharyngeal PCR 2, 3, 4

Third-Line Investigations (if cough persists >8 weeks or red flags present)

• High-resolution CT chest: Indicated if chest X-ray is normal but cough persists beyond 8 weeks, to evaluate for bronchiectasis, interstitial lung disease, or occult masses 2

• Bronchoscopy: Consider if all empiric therapies fail, to evaluate for endobronchial lesions, sarcoidosis, eosinophilic bronchitis, or occult infection 2

• Sinus CT scan: If UACS is strongly suspected but not responding to empiric therapy, though the positive and negative predictive values remain undefined 1

Critical Timeline Considerations

This patient is at the 2-3 week mark post-URI, which places him in the postinfectious cough window (3-8 weeks), but the presence of hemoptysis and nocturnal awakening elevates concern and mandates more aggressive evaluation than simple reassurance. 2, 3, 4

• At 3 weeks: Begin considering alternative diagnoses including pertussis, Mycoplasma/Chlamydophila pneumoniae, UACS, and GERD 4

• At 8 weeks: If cough persists, it must be reclassified as chronic cough and systematically evaluated for UACS, asthma, and GERD 2, 4

Common Pitfalls to Avoid

• Do not dismiss pertussis in a patient with cough beyond 2-3 weeks, even in vaccinated individuals—this is highly contagious and requires macrolide antibiotics when caught early 2, 3, 4

• Do not assume colored sputum indicates bacterial infection—most short-term coughs are viral even when producing colored phlegm, and antibiotics are contraindicated for postinfectious cough 2

• Do not overlook "silent" presentations of UACS, asthma, or GERD, as each can present with cough as the sole symptom 1, 2

• Do not delay chest X-ray in the presence of hemoptysis, even if "just streaks," as this is a red flag requiring radiographic exclusion of serious pathology 2, 4