What is the appropriate evaluation and treatment for a 17-year-old female with a persistent cough lasting one month?

Evaluation and Management of One-Month Cough in a 17-Year-Old Female

For a 17-year-old with a one-month cough, begin by determining if the cough is wet/productive or dry, as this fundamentally changes the diagnostic and treatment pathway according to CHEST guidelines. 1

Initial Clinical Assessment

Critical History Elements

• Determine cough quality: Wet/productive cough suggests protracted bacterial bronchitis (PBB) and requires antibiotics, while dry cough suggests upper airway cough syndrome (UACS), asthma, or gastroesophageal reflux disease (GERD) 1
• Look for specific cough pointers: Coughing with feeding, digital clubbing, hemoptysis, or weight loss indicate need for immediate advanced investigation 1
• Environmental tobacco smoke exposure must be identified and cessation advised 1
• Assess for post-infectious pattern: If cough began with a respiratory infection 3-8 weeks ago, consider post-infectious cough 2, 3

Physical Examination Focus

• Check for digital clubbing (suggests underlying lung disease requiring bronchoscopy/CT) 1
• Assess for nasal discharge, throat clearing, or postnasal drip (suggests UACS) 3
• Listen for wheezing (suggests asthma) 4

Management Algorithm for WET/PRODUCTIVE Cough

If the cough is wet or productive without specific cough pointers, prescribe 2 weeks of antibiotics targeting Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis based on local antibiotic sensitivities (Grade 1A recommendation). 1

Antibiotic Treatment Protocol

• If cough resolves within 2 weeks: Diagnose as protracted bacterial bronchitis (PBB) 1
• If wet cough persists after 2 weeks: Extend antibiotics for an additional 2 weeks (total 4 weeks) 1
• If wet cough persists after 4 weeks total: Proceed to further investigations including flexible bronchoscopy with quantitative cultures and/or chest CT 1

Red Flags Requiring Immediate Advanced Investigation

If wet cough is accompanied by specific cough pointers (coughing with feeding, digital clubbing), immediately pursue flexible bronchoscopy and/or chest CT, assessment for aspiration, and evaluation of immunologic competency to assess for underlying disease such as bronchiectasis, cystic fibrosis, or immunodeficiency (Grade 1B recommendation). 1

Management Algorithm for DRY Cough

Step 1: Empiric Treatment for Upper Airway Cough Syndrome (UACS)

Start with a first-generation antihistamine/decongestant combination (such as brompheniramine/pseudoephedrine or chlorpheniramine/phenylephrine) for 1-2 weeks. 2, 3

• Begin once-daily at bedtime for 2-3 days, then advance to twice-daily to minimize sedation 2
• Add intranasal corticosteroid spray (fluticasone or mometasone) to decrease airway inflammation 2

Step 2: If UACS Treatment Fails After 2 Weeks - Evaluate for Asthma

Proceed to asthma evaluation with spirometry and bronchodilator response testing, or if unavailable, initiate empiric trial of inhaled corticosteroids and bronchodilators. 1, 3

• Suspect asthma if cough worsens at night, with cold air exposure, or with exercise 3
• Response to bronchodilators may occur within 1 week, but complete resolution can take up to 8 weeks 3
• Consider non-asthmatic eosinophilic bronchitis if spirometry is normal but cough persists 1, 3

Step 3: If Both UACS and Asthma Treatments Fail - Treat for GERD

Initiate high-dose proton pump inhibitor therapy (omeprazole 40 mg twice daily), dietary modifications, and lifestyle changes, even without typical GI symptoms, as GERD can present with cough alone. 2, 3

• Critical pitfall: GERD-related cough may require 2 weeks to several months for response, with some patients needing 8-12 weeks before improvement, so adequate treatment duration is essential before declaring failure 1, 2, 3
• Do not use acid suppressive therapy solely for chronic cough in children without GI symptoms of GERD (Grade 1B recommendation) 1

GERD Treatment Considerations in Adolescents

For adolescents aged ≤14 years with chronic cough without underlying lung disease, treatment for GERD should NOT be used when there are no GI clinical features such as recurrent regurgitation or heartburn/epigastric pain (Grade 1B recommendation). 1

• However, if GI symptoms ARE present, treat according to evidence-based GERD guidelines for 4-8 weeks and reevaluate 1
• Acid suppressive therapy should not be used solely for chronic cough (Grade 1C recommendation) 1

Advanced Testing if All Empiric Therapy Fails

Order chest radiograph first to rule out pneumonia, masses, interstitial disease, or structural abnormalities. 1, 3

Indications for High-Resolution CT Chest

• Abnormal chest radiograph findings 1
• Clinical suspicion of bronchiectasis, interstitial lung disease, or occult masses 1, 3
• Persistent cough after adequate therapeutic trials of UACS, asthma, and GERD 1, 3

Common pitfall: Wide application of chest CT in all patients with chronic cough is not diagnostically rewarding, as studies show CT is noncontributory or normal in up to 48% of symptomatic patients 1

Indications for Bronchoscopy

• Wet cough persisting after 4 weeks of appropriate antibiotics 1
• Specific cough pointers present (digital clubbing, coughing with feeding) 1
• To evaluate for endobronchial lesions, sarcoidosis, eosinophilic bronchitis, or occult infection 2, 3

Special Consideration: Post-Tussive Vomiting

If post-tussive vomiting is present, pertussis must be ruled out first, even in vaccinated patients, as breakthrough infections occur. 2

• Obtain nasopharyngeal culture if pertussis is suspected based on paroxysmal coughing episodes 2
• If pertussis is confirmed or highly suspected, prescribe macrolide antibiotics immediately (azithromycin or clarithromycin) 2

Critical Pitfalls to Avoid

• Do not prescribe antibiotics for post-infectious viral cough, as they provide no benefit and contribute to resistance 2
• Do not use nasal decongestant sprays for more than 3-5 days due to rebound congestion risk 2
• Do not diagnose "unexplained cough" until completing systematic evaluation of UACS, asthma, and GERD with adequate treatment trials 1, 2, 3
• Do not use asthma or GERD medications empirically unless clinical features consistent with these conditions are present (Grade 1A recommendation) 1

Treatment Duration Expectations

• UACS treatment: Response expected within 1-2 weeks 2, 3
• Asthma treatment: Response may begin within 1 week but complete resolution can take up to 8 weeks 3
• GERD treatment: Response may take 2 weeks to several months, with some requiring 8-12 weeks 1, 2, 3
• PBB antibiotic treatment: Initial 2-week trial, extend to 4 weeks if needed 1