What is the diagnosis for a patient with a 2-week history of upper respiratory infection (URI) symptoms who now presents with a productive cough with gray sputum?

Acute Bronchitis with Progression to Productive Cough

This patient has acute bronchitis, a self-limited viral respiratory infection that has now progressed to the productive cough phase at 2 weeks. 1, 2

Immediate Diagnostic Priorities

Rule out pneumonia first by assessing vital signs and performing a focused lung examination. 1, 2 Pneumonia is excluded if the following are absent:

• Heart rate >100 beats/min 1, 2
• Respiratory rate >24 breaths/min 1, 2
• Temperature >38°C 1, 2
• Focal consolidation, egophony, or fremitus on chest exam 1, 2

If all four criteria are absent, chest radiography is not needed and pneumonia is sufficiently unlikely. 1, 2 The gray sputum does not distinguish bacterial from viral infection and does not indicate pneumonia or need for antibiotics. 1, 3

Confirming the Diagnosis

This presentation is classic for acute bronchitis because: 1, 4

• Cough duration is 2 weeks (within the typical 3-week course) 1, 4, 5
• Productive cough with sputum (gray color is nonspecific) developed after initial URI symptoms 1, 3
• No pneumonia features are present 1

The gray sputum represents normal progression of viral bronchitis, not bacterial superinfection. 1, 3 Sputum color and purulence do not reliably differentiate viral from bacterial infection. 6

Alternative Diagnoses to Consider

If cough persists beyond 3 weeks, consider: 1, 7

• Pertussis if paroxysmal cough, post-tussive vomiting, or whooping sound develops 7, 4
• Postinfectious cough (can last 3-8 weeks after viral infection) 7, 8
• Asthma if recurrent episodes or nocturnal/exercise-triggered symptoms 1, 8
• Upper airway cough syndrome if prominent nasal/sinus congestion persists 8

Evidence-Based Management

Do NOT prescribe antibiotics. 2, 4, 5 Antibiotics reduce cough duration by only 0.5 days while exposing patients to adverse effects including allergic reactions, nausea, and C. difficile infection. 4, 5 Viruses cause >90% of acute bronchitis cases. 2, 4, 6

Provide symptomatic treatment: 2

• Acetaminophen or ibuprofen for chest discomfort 2
• Pseudoephedrine for nasal congestion 2
• Adequate hydration and rest 2
• Ipratropium bromide inhaler if cough is bothersome beyond 3-5 days (the only effective cough suppressant for viral bronchitis) 2

Do NOT prescribe: 2

• Benzonatate or other cough suppressants (ineffective) 2
• Antihistamines alone (not effective for URI) 2
• Oral or inhaled corticosteroids (no benefit) 5

Patient Education and Follow-Up

Counsel the patient that: 2, 4, 5

• Cough typically lasts 2-3 weeks total and may persist up to 3 weeks 2, 4, 5
• Symptoms should peak at days 3-6 and improve thereafter 2
• Gray sputum is normal and does not require antibiotics 1, 3

Return for re-evaluation if: 2, 7

• Symptoms persist >3 weeks without improvement 2, 7
• New fever, dyspnea, or focal chest findings develop 2, 7
• Symptoms worsen after initial improvement 2