What is the diagnosis and management for a patient with a history of yellow phlegm now cleared but presenting with wheezing?

Diagnosis: Post-Infectious Reactive Airway Disease/Bronchospasm

This patient most likely has post-infectious reactive airway disease (bronchospasm) following a viral or bacterial respiratory infection, evidenced by the progression from purulent (yellow) to clear phlegm with new-onset wheezing. 1, 2

Clinical Reasoning

The clinical presentation follows a classic pattern:

• Yellow phlegm initially suggests a preceding respiratory infection (viral or bacterial) that has now resolved, as evidenced by the transition to clear phlegm 2
• Persistent wheezing with clear phlegm indicates bronchospasm/reactive airway disease rather than active infection 1, 3
• This pattern is consistent with post-infectious airway hyperreactivity, where the initial infection triggers ongoing bronchial inflammation and bronchospasm even after the infection clears 1, 4

Differential Diagnosis to Consider

Primary Considerations:

• Asthma exacerbation or cough-variant asthma: Recurrent wheezing, particularly if worsened at night or with triggers (exercise, cold air, irritants) 1
• Post-infectious bronchospasm: Most common after viral respiratory infections 2, 3
• Underlying COPD (if patient is a smoker): Chronic productive cough with wheezing 1

Less Likely (but important to exclude):

• Bacterial bronchitis/pneumonia: Would typically show persistent purulent sputum, not clearing to clear phlegm 2
• Anatomic abnormalities (tracheomalacia, foreign body): More common in infants/children with persistent symptoms 1
• Lung cancer: Consider in smokers >40 years with new-onset wheezing 1, 5

Recommended Management Algorithm

Immediate Treatment:

1. Initiate bronchodilator therapy with albuterol (short-acting β2-agonist) 2.5 mg via nebulizer 3-4 times daily 2, 3, 6

   • Albuterol reduces cough duration and severity in approximately 50% of patients by day 7 2
   • This addresses the bronchospasm component causing the wheezing 3, 6

2. Do NOT prescribe antibiotics unless there are specific indications 2

   • More than 90% of acute bronchitis cases are viral 2
   • Yellow phlegm that has cleared to white/clear indicates resolved infection 2
   • Antibiotics provide no meaningful clinical benefit in uncomplicated bronchitis 2

If Wheezing Persists After 3-5 Days:

1. Add oral corticosteroids if wheezing is moderate to severe (prednisone 40-60 mg daily for 5 days) 3, 4

2. Consider inhaled corticosteroids if wheezing persists despite bronchodilator therapy 3, 4

Essential Diagnostic Workup:

1. Obtain chest radiograph to exclude pneumonia, lung cancer, or other structural abnormalities 1

   • Mandatory in all patients with chronic cough/wheezing 1
   • Essential in patients >40 years with smoking history and new-onset wheezing 5

2. Perform spirometry with bronchodilator challenge 1, 4

   • Demonstrates reversible airflow obstruction characteristic of asthma 1, 4
   • Helps differentiate asthma from COPD 1

Special Considerations

If Patient is an Infant or Young Child:

• Consider flexible fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) if wheezing persists despite bronchodilator and corticosteroid treatment 1, 3, 7
• Approximately 33% of infants with persistent wheezing have anatomic abnormalities (tracheomalacia, vascular rings) 1, 7
• 40-60% have positive BAL cultures indicating bacterial infection 1, 2, 3

If Patient Has COPD:

• Prescribe antibiotics ONLY if 2 of 3 Anthonisen criteria present: increased sputum volume, increased sputum purulence, increased dyspnea 2
• First-line: amoxicillin or azithromycin 500 mg daily for 3 days 2

Common Pitfalls to Avoid

• Do not empirically prescribe antibiotics for wheezing with clear phlegm—this increases antibiotic resistance without benefit 2
• Do not use long-acting β2-agonists alone without inhaled corticosteroids in asthma 4
• Do not dismiss persistent wheezing in infants—anatomic abnormalities require bronchoscopy for diagnosis 1, 7
• Do not assume all wheezing is asthma—obtain chest X-ray to exclude malignancy, especially in smokers 1, 5

Patient Education

• Explain that cough typically lasts 10-14 days after initial infection 2
• Set realistic expectations that wheezing may take several days to resolve with bronchodilator therapy 2, 3
• Teach proper inhaler technique and consider spacer device 1, 4
• Identify and avoid triggers (smoke, allergens, cold air, exercise) 1