What further evaluation and management are recommended for a patient with a complex medical history, presenting with dry cough, rhinorrhea, and shortness of breath, unresponsive to initial treatment with prednisone and azithromycin?

Further Evaluation and Management

This patient requires immediate evaluation for acute asthma exacerbation with spirometry showing moderate-to-severe obstruction (FEV1 53%), and the current treatment with prednisone and azithromycin should be continued while systematically addressing the underlying chronic cough through sequential evaluation of upper airway cough syndrome (UACS), poorly controlled asthma, and gastroesophageal reflux disease (GERD). 1, 2

Immediate Assessment and Acute Management

Confirm Acute Asthma Exacerbation

• Obtain pulse oximetry immediately to assess oxygenation status given the new-onset dyspnea and significantly reduced spirometry values (FEV1 53%, FEV1/FVC 82% suggesting obstruction) 1
• Perform chest radiograph to rule out pneumonia, pulmonary embolism, or other acute processes, as this is recommended for all patients with chronic cough and acute symptom changes 1
• The spirometry results demonstrate moderate airflow obstruction with preserved FEV1/FVC ratio, consistent with asthma rather than COPD 1

Optimize Acute Asthma Treatment

• Continue the prednisone 20 mg daily for 5 days as already prescribed, which is appropriate for acute exacerbation 1, 2
• Reassess azithromycin indication: While azithromycin has shown benefit in non-eosinophilic severe asthma for preventing exacerbations, its role in acute treatment is limited unless bacterial infection is confirmed 3
• Intensify bronchodilator therapy with scheduled short-acting beta-agonists (albuterol every 4-6 hours) rather than as-needed use during the acute phase 1
• Ensure the patient is using proper inhaler technique for her maintenance asthma medications 1

Systematic Evaluation of Chronic Cough (3 weeks duration)

First Priority: Upper Airway Cough Syndrome (UACS)

The patient's significant post-nasal drip and rhinorrhea strongly suggest UACS as a primary contributor 1, 2:

• Initiate first-generation antihistamine/decongestant combination (e.g., brompheniramine/pseudoephedrine or chlorpheniramine/phenylephrine) starting once daily at bedtime for 2-3 days, then advance to twice daily 2
• Add intranasal corticosteroid spray (fluticasone or mometasone) to decrease airway inflammation 2
• Trial for 1-2 weeks before concluding treatment failure 1, 2

Second Priority: Poorly Controlled Asthma

Given her documented asthma history and significantly reduced spirometry 1:

• Review and optimize maintenance inhaled corticosteroid/long-acting beta-agonist therapy - ensure she's on adequate dosing 1
• Consider adding leukotriene receptor antagonist (montelukast) if not already prescribed 1
• If cough persists after UACS treatment and despite optimized asthma therapy, consider trial of higher-dose inhaled corticosteroids or short course of oral corticosteroids (prednisone 30-40 mg daily for 5-7 days) 2

Third Priority: Gastroesophageal Reflux Disease (GERD)

If UACS and asthma treatments fail after 2 weeks 1, 2:

• Initiate high-dose proton pump inhibitor therapy (omeprazole 40 mg twice daily or equivalent) 2
• Implement dietary modifications: avoid late meals, elevate head of bed, avoid trigger foods 2
• Allow adequate treatment duration: GERD-related cough may require 2 weeks to several months for response, with some patients needing 8-12 weeks 2

Additional Diagnostic Considerations

Pertussis Evaluation

Given the 3-week duration and temporal relationship to flu vaccination 1:

• Consider pertussis serology or PCR if paroxysmal cough develops, though less likely given current presentation 1, 2
• Pertussis has been implicated in 10% of chronic cough cases in some series 1

Post-Viral Bronchial Hyperresponsiveness

The worsening after flu shot may represent coincidental viral infection 2:

• The clinical presentation suggests post-infectious cough with bronchial hyperresponsiveness 2
• Consider inhaled ipratropium bromide 2-3 puffs four times daily if cough persists despite other measures 2

Advanced Testing if All Empiric Therapy Fails

After completing adequate trials of UACS, asthma, and GERD treatment (typically 4-8 weeks total) 1, 2:

• High-resolution CT chest to evaluate for bronchiectasis, interstitial lung disease, or occult masses 2
• Bronchoscopy to evaluate for endobronchial lesions, eosinophilic bronchitis, or occult infection 2
• 24-hour esophageal pH monitoring if GERD remains suspected despite failed empiric therapy 2

Critical Pitfalls to Avoid

• Do not repeat or continue azithromycin beyond the current 5-day course - this patient's presentation is consistent with post-infectious/post-viral cough and UACS, not bacterial infection requiring prolonged antibiotics 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 of 1-2 weeks each 1, 2
• Do not rely on PRN medications alone - ensure scheduled maintenance therapy for both asthma and UACS 1
• Multiple causes often coexist - therapy should be given in sequential and additive steps rather than stopping one treatment when starting another 1

Monitoring and Follow-up

• Reassess in 48-72 hours for acute dyspnea symptoms and response to prednisone 1
• Weekly follow-up during the systematic evaluation phase to assess treatment response 1
• Repeat spirometry in 3-4 weeks after acute treatment to establish baseline lung function 1
• Consider referral to pulmonology or cough specialist if symptoms persist after completing the systematic evaluation algorithm 1