A 44-year-old woman presents with a three‑day dry cough and occasional yellow sputum following a febrile upper‑respiratory infection seven days ago that was treated with azithromycin; she is now afebrile. What is the most likely diagnosis and appropriate management?

Postinfectious Cough Following Upper Respiratory Tract Infection

This is postinfectious cough (subacute cough), and antibiotics are NOT indicated—the azithromycin has already addressed any bacterial component from the initial infection. 1

Diagnosis

Your patient has developed a postinfectious cough, which is a clinical diagnosis. This occurs when cough persists beyond the acute phase of an upper respiratory infection but lasts less than 8 weeks (subacute cough). The timeline fits perfectly: she had fever and throat pain 7 days ago (treated appropriately with azithromycin), and now presents 3 days into a persistent cough with occasional yellow sputum but no fever 1.

The pathophysiology involves extensive inflammation and disruption of airway epithelial integrity from the initial viral infection, often with mucus hypersecretion and transient airway hyperresponsiveness—not ongoing bacterial infection 1.

Key Clinical Points:

• Chest X-ray should be normal (ruling out pneumonia)
• The cough is self-limited and typically resolves on its own
• Yellow sputum does NOT indicate bacterial infection requiring antibiotics in this context
• Most cases resolve within 3-8 weeks 1

Important Caveat - Rule Out Pertussis:

If she develops paroxysms of coughing, posttussive vomiting, or inspiratory whooping, consider Bordetella pertussis infection, which would require different management 1. However, this is less likely given her presentation.

Treatment Approach

Do NOT prescribe additional antibiotics. The evidence is clear that antibiotics have no role in postinfectious cough except for bacterial sinusitis or early pertussis 1.

Recommended Management Algorithm:

1. First-line: Inhaled ipratropium bromide

   • This has evidence for attenuating postinfectious cough 1
   • Grade B recommendation with fair evidence 1

2. If cough persists and significantly affects quality of life despite ipratropium:

   • Consider inhaled corticosteroids (e.g., fluticasone)
   • Alternative: Short course of oral corticosteroids (prednisone 30-40 mg daily, tapering over 2-3 weeks) 1
   • This addresses the underlying inflammatory mechanism

3. Symptomatic support:

   • Patient education is crucial: explain the cough typically lasts 2-3 weeks and is self-limiting 2
   • Avoid antitussives, honey, antihistamines, or NSAIDs—no evidence of benefit 2

4. If cough persists beyond 8 weeks:

   • Reconsider the diagnosis
   • Evaluate for upper airway cough syndrome (postnasal drip), asthma, or GERD 1

Common Pitfalls to Avoid

• Do not prescribe more antibiotics just because of yellow sputum—this represents normal inflammatory response, not bacterial superinfection
• The azithromycin she already received was appropriate for the initial pharyngitis but has no role now 1, 3
• Avoid the temptation to treat with antibiotics to "cover" possible bacterial bronchitis—acute bronchitis is viral and antibiotics only reduce cough duration by 0.5 days while exposing patients to adverse effects 2
• Setting realistic expectations prevents unnecessary follow-up visits and antibiotic pressure

Bottom line: Reassure, prescribe inhaled ipratropium, and educate that this will resolve with time.