How should I evaluate and treat a 38‑year‑old man with a one‑month persistent cough, continuous rhinorrhea, dry daytime cough, and thick yellow sputum in the mornings, who has no chronic lung disease, recent travel, immunosuppression, or smoking history?

Evaluation and Management of Persistent Cough with Rhinorrhea and Morning Sputum

Initial Assessment and Most Likely Diagnosis

This clinical presentation—one month of persistent cough with continuous rhinorrhea, dry daytime cough, and thick yellow morning sputum—is most consistent with upper airway cough syndrome (UACS), and you should initiate empiric treatment with a first-generation antihistamine-decongestant combination immediately. 1, 2

The thick yellowish morning mucus does not indicate bacterial infection requiring antibiotics; colored sputum is common in viral upper respiratory infections and UACS, and antibiotics are explicitly contraindicated unless there is radiographic evidence of pneumonia or confirmed bacterial sinusitis. 2, 1

Critical Rule-Outs Before Proceeding

Before diagnosing UACS, you must exclude three conditions:

• Pneumonia: Check vital signs (fever, tachypnea, oxygen saturation), auscultate for focal crackles or diminished breath sounds, and obtain a chest X-ray if any focal findings, fever >4 days, dyspnea, or tachypnea are present. 1
• Acute bronchitis vs. common cold: The one-month duration makes acute bronchitis (typically ≤3 weeks) unlikely; this is now either postinfectious cough or chronic cough requiring systematic evaluation. 1, 2
• Asthma exacerbation: Listen for wheezing during forced expiration or after coughing; ask about triggers (cold air, exercise, nighttime worsening). 1

Diagnostic Approach for UACS

The diagnosis of UACS is made clinically and confirmed by response to treatment. Key features supporting UACS include: 1, 3

• Continuous rhinorrhea (present in this patient)
• Sensation of postnasal drip or frequent throat clearing
• Nasal congestion or sinus pressure
• Cobblestoning of posterior pharynx on exam

Physical examination should focus on: 4

• Nasal inspection for pale/boggy turbinates (allergic) vs. erythematous turbinates (infectious)
• Oropharyngeal exam for cobblestoning or pharyngeal drainage
• Lung auscultation to exclude wheezing or crackles

First-Line Treatment Algorithm

Step 1: Initiate UACS therapy 1, 2

• Prescribe a first-generation antihistamine-decongestant combination (e.g., brompheniramine/pseudoephedrine or chlorpheniramine/phenylephrine)
• Add an intranasal corticosteroid spray (fluticasone or mometasone)
• Expected response time: improvement within days to 1–2 weeks, with complete resolution potentially requiring several weeks to months 1

Step 2: Supportive care 2

• Recommend guaifenesin 200–400 mg every 4 hours (up to 6 times daily) to help loosen secretions
• Advise adequate hydration, warm facial packs, steamy showers, and sleeping with head elevated

If Partial or No Response After 1–2 Weeks

If cough persists but rhinorrhea improves, proceed to evaluate for asthma: 1, 3

• Perform spirometry with bronchodilator response or bronchoprovocation challenge (methacholine)
• If testing unavailable or positive, initiate empiric trial of inhaled corticosteroids (fluticasone 220 mcg or budesonide 360 mcg twice daily) plus short-acting beta-agonist
• Allow up to 8 weeks for full response 1

If rhinorrhea persists despite topical therapy, consider: 1

• Sinus imaging (CT scan) to evaluate for acute or chronic sinusitis
• If air-fluid levels present, prescribe antibiotics for bacterial sinusitis
• If mucosal thickening only, treat presumptively for sinusitis in the setting of refractory cough

If Cough Persists Beyond 3–8 Weeks

At 8 weeks, reclassify as chronic cough and systematically evaluate the "big three" causes: 2, 3

1. UACS (already addressed above)
2. Asthma (including cough-variant asthma)
   • Bronchoprovocation challenge has ~100% negative predictive value 1
   • Positive challenge warrants asthma treatment trial
3. GERD (even without typical GI symptoms—"silent GERD" is common) 1, 3
   • Initiate high-dose PPI (omeprazole 40 mg twice daily) with dietary modifications
   • Response may require 2 weeks to several months 1

Chronic cough is frequently multifactorial—partial improvement with one treatment means continuing that therapy and adding the next intervention, not stopping and switching. 1, 3

Advanced Evaluation if All Empiric Therapies Fail

If cough persists despite adequate trials (≥8 weeks of combined therapy): 3, 4

• High-resolution CT chest to evaluate for bronchiectasis, interstitial lung disease, or occult masses
• 24-hour esophageal pH monitoring if GERD suspected but PPI trial failed
• Bronchoscopy to evaluate for endobronchial lesions, eosinophilic bronchitis, sarcoidosis, or occult infection

What NOT to Do: Critical Pitfalls

• Do not prescribe antibiotics for this presentation—the thick yellow sputum does not indicate bacterial infection, and antibiotics have no role in postinfectious cough or UACS unless there is confirmed bacterial sinusitis or pneumonia. 2, 1
• Do not order sinus CT immediately—the positive predictive value for cough resolution is low (~67%); reserve imaging for cases refractory to empiric therapy. 1
• Do not assume a single cause—up to 59% of chronic cough cases have multiple simultaneous contributors, and all must be treated for resolution. 1, 5
• Do not stop therapy prematurely—UACS may take weeks to months to fully resolve, asthma trials require up to 8 weeks, and GERD trials may require several months. 1, 2

Red Flags Requiring Immediate Re-Evaluation

Instruct the patient to return immediately if: 2, 4

• Hemoptysis develops (requires urgent chest X-ray)
• Fever develops or persists beyond 4 days
• Dyspnea or respiratory distress occurs
• Weight loss, night sweats, or systemic symptoms appear

Expected Timeline and Follow-Up

• 1–2 weeks: Reassess response to UACS therapy; if no improvement, add asthma evaluation 1, 2
• 3–8 weeks: If cough persists, this is postinfectious cough; consider adding inhaled ipratropium bromide 2–3 puffs four times daily (strongest evidence for postinfectious cough) 2
• 8 weeks: Reclassify as chronic cough and systematically evaluate for UACS, asthma, and GERD 2, 3