What is the recommended treatment for sinus infections in adults?

Treatment of Sinus Infections in Adults

For adults with acute bacterial rhinosinusitis (ABRS), either watchful waiting without antibiotics OR amoxicillin with or without clavulanate for 5-10 days are both appropriate initial strategies, with the choice depending on symptom severity and patient reliability for follow-up. 1, 2

Distinguishing Bacterial from Viral Sinusitis

Before treating, you must first determine if this is bacterial or viral:

• Diagnose ABRS when: 1, 2

  • Symptoms persist ≥10 days without improvement, OR
  • Symptoms worsen within 10 days after initial improvement ("double worsening")

• Viral rhinosinusitis (VRS): 3, 2

  • Self-limited, typically lasting 7-10 days
  • Accounts for most acute sinusitis cases
  • Does NOT require antibiotics

Common pitfall: Do not rely on purulent (colored) nasal discharge alone to diagnose bacterial infection—mucus color reflects neutrophils, not bacteria. 2

Treatment Algorithm for Acute Bacterial Rhinosinusitis

Step 1: Assess Severity and Patient Factors

For uncomplicated ABRS with mild symptoms (mild pain, temperature <38.3°C/101°F): 1, 2

• Watchful waiting without antibiotics is appropriate if reliable follow-up is assured
• Exclude patients with: severe illness, complicated sinusitis, immune deficiency, prior sinus surgery, or coexisting bacterial illness

For moderate to severe symptoms OR unreliable follow-up: 1, 2

• Proceed directly to antibiotic therapy

Step 2: First-Line Antibiotic Selection

Amoxicillin with or without clavulanate for 5-10 days is the first-line antibiotic choice. 1, 2, 4

• Amoxicillin-clavulanate is preferred in diabetic patients 4
• Demonstrated superiority over placebo with comparable outcomes to broader-spectrum agents 1
• Most cost-effective option with potential to reduce bacterial resistance 1

For penicillin-allergic patients: 1, 3, 4

• Doxycycline, OR
• Respiratory fluoroquinolone (levofloxacin or moxifloxacin) 4, 5
• Cephalosporins (cefuroxime, cefpodoxime) if not anaphylactically allergic 4

Important caveat: Azithromycin is NOT recommended as first-line therapy—short courses (like 5-day regimens) are often insufficient for complete bacterial eradication. 4, 6

Step 3: Symptomatic Management (For ALL Patients)

Regardless of antibiotic decision, provide symptomatic relief: 1, 3, 2

• Analgesics: NSAIDs or acetaminophen for facial pain (strong recommendation) 1, 3
• Intranasal corticosteroids: Reduce inflammation and improve symptoms 1, 3, 2
• Saline nasal irrigation: Improves mucociliary clearance; buffered hypertonic (3%-5%) saline may be superior to isotonic 1, 3, 2
• Decongestants: May provide relief but limited evidence; topical decongestants should NOT be used >3-5 days (risk of rhinitis medicamentosa) 1, 3

Avoid antihistamines in non-allergic patients—they may worsen congestion by drying nasal mucosa. 1

Step 4: Reassessment at 7 Days

If patient worsens OR fails to improve by 7 days: 1

• Reassess to confirm ABRS diagnosis
• Exclude other causes and detect complications
• If initially managed with observation: Start antibiotic therapy
• If initially managed with antibiotics: Change to a different antibiotic class

Treatment for Chronic Rhinosinusitis (CRS)

CRS is defined as symptoms lasting ≥12 weeks and requires objective documentation of sinonasal inflammation via anterior rhinoscopy, nasal endoscopy, or CT scan (strong recommendation). 1, 2

First-line treatment for CRS: 2

• Saline nasal irrigation AND/OR topical intranasal corticosteroids
• Short courses of systemic corticosteroids may benefit patients with nasal polyps 2

Antibiotics should be reserved for acute exacerbations with evidence of bacterial infection. 2

Do NOT use antifungal therapy (topical or systemic) for CRS—this is a recommendation against based on lack of efficacy. 2

When to Obtain Imaging or Specialist Referral

CT imaging is indicated when: 2, 4

• Confirming CRS diagnosis
• Symptoms persist after 10 days of appropriate antibiotic therapy 4
• Complications suspected (meningeal signs, orbital involvement, severe headache)
• Recurrent episodes despite adequate treatment 4

Plain radiographs are NOT recommended—they have only 76% sensitivity and should not guide management. 1, 4

Refer to otolaryngology when: 4

• Symptoms persist despite appropriate therapy
• Radiologic signs show mucosal thickening >4mm
• Recurrent episodes or complications present

Key Clinical Pitfalls to Avoid

• Overusing antibiotics for viral infections: Most acute sinusitis is viral and self-limited 3, 2
• Prescribing antibiotics based on symptom duration <10 days: Unless severe symptoms with high fever and unilateral facial pain 1, 7
• Prolonged topical decongestant use: Leads to rebound congestion 1, 3
• Failing to confirm CRS with objective findings: Clinical symptoms alone are insufficient 1, 2
• Using short-course azithromycin: Often inadequate for complete bacterial eradication 4