What is the assessment and treatment approach for an 18-year-old female with a persistent cough?

Assessment and Treatment of Persistent Cough in an 18-Year-Old Female

Begin with a systematic evaluation starting with history and physical examination to classify the cough duration, then sequentially evaluate and treat the three most common causes: upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD), using both empiric therapy and targeted diagnostic testing. 1

Initial Assessment

Critical Historical Elements

• Determine cough duration: Classify as acute (<3 weeks), subacute (3-8 weeks), or chronic (>8 weeks) as this fundamentally changes your diagnostic approach 1, 2
• Medication review: Immediately ask about ACE inhibitor use and discontinue if present—cough typically resolves within days to 2 weeks (median 26 days) 1, 2
• Smoking status: If she smokes, counsel on cessation as 90-94% experience cough resolution within the first year of quitting 2
• Red flag symptoms: Assess for fever, hemoptysis, weight loss, night sweats, dyspnea, or abnormal vital signs that would indicate serious pathology requiring urgent evaluation 3, 2

Physical Examination Focus

• Examine for signs of upper airway disease (rhinorrhea, throat clearing, cobblestoning of posterior pharynx) 1
• Auscultate lungs for wheezing or other abnormalities 2
• Check vital signs including oxygen saturation 3

Initial Diagnostic Testing

• Chest radiograph: Obtain to rule out significant pathology 4, 2
• Spirometry: Perform as part of basic evaluation for chronic cough, looking for reversible airflow obstruction suggestive of asthma 4, 2

Management Based on Duration

If Subacute Cough (3-8 weeks)

First determine if this is post-infectious cough following a recent upper respiratory infection. 1, 3

If post-viral with clear lungs, normal oxygen saturation, and no fever:

• No antibiotics, chest X-ray, or bronchodilators needed 3
• Recommend simple measures: honey, warm fluids, or simple linctuses for symptomatic relief 3
• Consider dextromethorphan 60 mg for maximum cough suppression 3
• Trial first-generation antihistamine plus decongestant if postnasal drip suspected 3
• NSAIDs (naproxen) may favorably affect cough 3
• Follow-up if cough persists beyond 8 weeks, as this would meet criteria for chronic cough requiring systematic evaluation 3, 2

If NOT post-infectious, evaluate and manage as chronic cough below. 1

If Chronic Cough (>8 weeks)

Use a sequential and additive treatment approach targeting the three most common causes, which frequently coexist in 59% of cases. 1, 5

Step 1: Treat Upper Airway Cough Syndrome (UACS)

• Start first-generation antihistamine/decongestant combination (e.g., diphenhydramine plus pseudoephedrine) 4, 2
• Add intranasal corticosteroid if prominent upper airway symptoms present 2
• Expect response within 1-2 weeks, though complete resolution may take several weeks 4
• Do not discontinue if only partial improvement—multiple causes often coexist 1, 2

Step 2: Add Asthma Treatment

• If spirometry shows reversible airflow obstruction: treat with inhaled corticosteroids (ICS) plus long-acting β-agonist (LABA) such as fluticasone/salmeterol twice daily 4, 2
• If spirometry is normal but asthma suspected: consider bronchoprovocation challenge with methacholine 4, 2
• Alternatively, proceed with empiric trial of ICS plus bronchodilator 4, 2
• Monitor for response within 2-4 weeks 4
• Continue UACS treatment as you add asthma therapy 4

Step 3: Consider Non-Asthmatic Eosinophilic Bronchitis (NAEB)

• If available, perform induced sputum testing for eosinophils 4, 2
• If testing unavailable, use empiric trial of inhaled corticosteroids 2
• Treat with systemic steroids if NAEB confirmed 1

Step 4: Add GERD Treatment

• For patients with prominent GERD symptoms: start treatment earlier in algorithm 1
• Initiate proton pump inhibitor (PPI) therapy 1, 4
• Implement antireflux diet and lifestyle modifications 1
• Response timeframe is variable: some respond within 2 weeks, others may take several months 1
• If inadequate response, add prokinetic agent (metoclopramide) and ensure rigorous dietary adherence 1
• Continue all previous treatments as cough is often multifactorial 4

Advanced Evaluation if Initial Treatment Fails

After 4-6 weeks of empiric treatment for the top diagnoses without adequate response: 2

Objective Testing

• 24-hour esophageal pH monitoring if GERD suspected but not responding to empiric therapy 1
• High-resolution CT scan to evaluate for bronchiectasis or occult interstitial disease 1, 2
• Bronchoscopy to look for occult airway disease (endobronchial tumor, sarcoidosis, eosinophilic or lymphocytic bronchitis) 1, 2

Uncommon Causes to Consider

• Nonacid reflux disease 1
• Swallowing disorder 1
• Habit cough or tic disorders (though rare in adults—only 4 reported cases in adults vs. 149 in pediatric/adolescent populations) 1

Follow-Up Strategy

• Reassess at 2-4 week intervals to evaluate treatment response 4
• Do not label as idiopathic until thorough assessment excludes uncommon causes 1, 2
• Consider specialist referral if cough persists despite sequential trials of therapy for common causes 4, 2

Critical Pitfalls to Avoid

• Do not rely on cough characteristics (timing, quality, productivity) for diagnosis—these have no diagnostic value 1, 5
• Do not treat only one cause—multiple factors contribute simultaneously in 59% of cases, requiring additive therapy 1, 2, 5
• Do not stop partially effective treatments when adding new therapies 1, 2
• Do not diagnose habit or psychogenic cough until extensive evaluation performed, tic disorders ruled out, and specific therapy (behavior modification/psychiatric therapy) has been tried and improved symptoms 1

Key Clinical Pearl

In an 18-year-old female nonsmoker with normal chest radiograph, UACS, asthma, and GERD account for 99.4% of chronic cough cases. 5 This clinical profile predicts that sequential evaluation and treatment of these three conditions will resolve cough in the vast majority of patients. 1, 5