How do I differentiate and treat bronchitis versus sinusitis?

Differentiating and Treating Bronchitis versus Sinusitis

Bronchitis and sinusitis are distinct clinical entities that can be reliably differentiated by symptom duration, location of symptoms, and specific physical findings—bronchitis presents primarily with cough and chest symptoms, while sinusitis presents with persistent purulent nasal discharge, facial pain, and nasal obstruction lasting beyond 10 days. 1, 2

Key Distinguishing Features

Sinusitis Cardinal Symptoms

• Purulent rhinorrhea (thick, colored nasal discharge) is the hallmark of sinusitis, not bronchitis 1, 2
• Facial or dental pain/pressure/fullness localizes to the sinuses 1
• Nasal obstruction or congestion is prominent 1, 2
• Postnasal drainage is a defining feature 1, 2
• Symptoms persist beyond 10-14 days without improvement, or worsen within 10 days after initial improvement (double worsening pattern) 1, 2

Bronchitis Cardinal Symptoms

• Cough is the predominant symptom in bronchitis, often productive 3
• Chest symptoms (chest tightness, wheezing) predominate over nasal symptoms 1
• Symptoms typically resolve within 5-7 days for viral bronchitis 2
• Facial pain and purulent nasal discharge are absent or minimal 3

Critical Diagnostic Timeline

The 10-day rule is essential for distinguishing bacterial sinusitis from viral upper respiratory infections (which can cause both bronchitis and viral rhinosinusitis). 1, 2 Suspect acute bacterial rhinosinusitis when:

1. Symptoms persist ≥10 days without improvement 1, 2
2. Symptoms worsen within 10 days after initial improvement (double worsening) 1, 2
3. Severe symptoms (fever >102°F, purulent discharge, facial pain) present for ≥3 days 3

Physical Examination Findings

For Sinusitis

• Sinus tenderness on palpation over maxillary or frontal sinuses 1, 2
• Purulent secretions (yellow-green, green, or gray) visible in nasal passages or middle meatus 1, 2
• Periorbital edema or dark circles beneath eyes (allergic shiners) 1, 2
• Red, swollen nasal mucosa 2
• Purulent material in posterior pharynx 1

For Bronchitis

• Chest auscultation reveals wheezes, rhonchi, or prolonged expiration 1
• Nasal examination is typically normal or shows clear discharge 1
• No sinus tenderness 2

Treatment Approach

Acute Bacterial Sinusitis Treatment

Amoxicillin with or without clavulanate is first-line antibiotic therapy for 5-10 days in most adults with acute bacterial rhinosinusitis. 1 However, watchful waiting without antibiotics is appropriate when follow-up is assured, starting antibiotics only if symptoms fail to improve by 7 days or worsen at any time. 1

Antibiotic selection:

• First-line: Amoxicillin 500 mg three times daily or amoxicillin-clavulanate 1, 4
• Alternative (beta-lactam allergy): Doxycycline or respiratory fluoroquinolone 3
• Azithromycin 500 mg once daily for 3 days is FDA-approved for acute bacterial sinusitis 4

Symptomatic relief for sinusitis:

• Nasal saline irrigation 1, 3
• Topical intranasal corticosteroids 1, 3
• Analgesics for pain 1, 3
• Decongestants may provide symptom relief 3

Acute Bronchitis Treatment

Most acute bronchitis is viral and does not require antibiotics. 3 Treatment focuses on:

• Symptomatic relief with bronchodilators if wheezing present 1
• Cough suppressants as needed 3
• Analgesics for chest discomfort 3

Common Pitfalls to Avoid

Do not diagnose bacterial sinusitis before 10 days of symptoms—most viral URIs resolve within 5-7 days, and premature antibiotic use contributes to resistance. 1, 2, 3

Do not rely solely on colored nasal discharge—while purulent rhinorrhea suggests bacterial infection, it can occur with viral infections; the key distinguishing feature is persistence beyond 10 days. 2, 3

Do not miss underlying allergic rhinitis—it is the most common predisposing factor for sinusitis and requires concurrent management with antihistamines or nasal corticosteroids. 1, 2

Do not order routine imaging—plain radiographs have significant false-positive and false-negative results and are not recommended for routine diagnosis. 1, 2 Reserve CT imaging for suspected complications, recurrent disease, or when diagnosis is uncertain. 1, 2, 3

Recognize the sinobronchial connection—chronic or recurrent cases of both conditions may indicate underlying disease (cystic fibrosis, ciliary dyskinesia, immunodeficiency) requiring specialized evaluation. 1, 5

When to Reassess or Refer

Reassess patients who worsen or fail to improve within 7 days of initial management to confirm diagnosis, exclude complications, and consider antibiotic change if initially treated. 1

Refer to otolaryngology for recurrent sinusitis (≥3 episodes per year), chronic sinusitis (≥8 weeks duration), suspected complications (orbital cellulitis, meningitis), or nasal polyps requiring surgical intervention. 1, 3