What is the treatment for sinusitis?

Treatment of Sinusitis

Distinguish Viral from Bacterial Sinusitis First

Most cases of acute rhinosinusitis (98-99.5%) are viral and resolve spontaneously within 7-10 days without antibiotics—reserve antibiotics only for confirmed bacterial sinusitis. 1, 2

Diagnose acute bacterial sinusitis when symptoms meet one of three specific patterns: 1, 2

• Persistent symptoms ≥10 days without clinical improvement
• Severe symptoms (fever ≥39°C with purulent nasal discharge and facial pain) for ≥3 consecutive days
• "Double sickening" - worsening symptoms after initial improvement from a viral upper respiratory infection

First-Line Antibiotic Treatment for Acute Bacterial Sinusitis

Amoxicillin remains the first-line antibiotic for uncomplicated acute bacterial sinusitis in both adults and children. 1, 2

Adult Dosing:

• Mild disease: 500 mg twice daily for 10-14 days 1, 3
• Moderate disease or high-resistance areas: 875 mg twice daily for 10-14 days 1, 3

Pediatric Dosing:

• Standard therapy: 45 mg/kg/day in 2 divided doses 3
• High-dose therapy (age <2 years, daycare attendance, recent antibiotic use, or high-resistance areas): 80-90 mg/kg/day in 2 divided doses 1, 3

Treatment duration should continue until symptom-free for 7 days, typically 10-14 days total. 2, 3

Second-Line Treatment for Antibiotic Failure

If no improvement occurs after 3-5 days of initial amoxicillin therapy, switch to high-dose amoxicillin-clavulanate. 4, 3

• Adults: 875 mg/125 mg twice daily 3
• Children: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 1, 3

The clavulanate component provides essential coverage against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis, which account for treatment failures. 3

For persistent failure after amoxicillin-clavulanate, respiratory fluoroquinolones (levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily for 10 days) provide 90-92% predicted clinical efficacy against drug-resistant organisms. 1, 3

Penicillin-Allergic Patients

For non-severe penicillin allergy (rash, mild reactions), second- or third-generation cephalosporins are safe and effective first-line alternatives. 1, 3

Recommended options include: 4, 3

• Cefuroxime-axetil (second-generation)
• Cefpodoxime-proxetil (third-generation)
• Cefdinir (third-generation)
• Cefprozil (third-generation)

For severe beta-lactam allergy or true anaphylaxis, use respiratory fluoroquinolones (levofloxacin or moxifloxacin) as first-line therapy. 3

Critical pitfall: Azithromycin and other macrolides should NOT be used due to resistance rates exceeding 20-25% for both S. pneumoniae and H. influenzae. 1, 3

Adjunctive Therapies (Use in ALL Patients)

Intranasal corticosteroids are strongly recommended as adjunctive therapy in both acute and chronic sinusitis to reduce inflammation and improve drainage. 1, 2, 3

• Fluticasone propionate: 200 mcg/day (two 50-mcg sprays in each nostril once daily) 5
• Maximum benefit may take several days, though some symptom relief occurs within 12 hours 5
• Continue for the duration of antibiotic therapy and beyond as needed 4

Additional supportive measures include: 1, 2

• Analgesics (acetaminophen or NSAIDs) for pain relief
• Saline nasal irrigation (high-volume daily irrigation for chronic cases)
• Adequate hydration
• Warm facial packs
• Sleeping with head elevated
• Decongestants (systemic or topical, limited to 3-5 days for topical to avoid rebound)

Chronic Sinusitis Management (Symptoms >8 Weeks)

Chronic sinusitis requires a fundamentally different approach than acute bacterial sinusitis—intranasal corticosteroids become first-line therapy, not antibiotics. 1, 2

Treatment algorithm: 4, 2

• First-line: Intranasal corticosteroids daily
• Second-line: Daily high-volume saline irrigation
• Third-line: Longer duration antibiotic therapy (minimum 3 weeks) only for chronic infectious sinusitis
• Consider: Short course of systemic corticosteroids or doxycycline for nasal polyps 2

Chronic hyperplastic eosinophilic rhinosinusitis does not respond to antibiotics and may require systemic corticosteroids. 4

When to Refer to a Specialist

Refer patients to an otolaryngologist or allergist-immunologist for: 1, 2

• Sinusitis refractory to two courses of appropriate antibiotics
• Recurrent sinusitis (≥3 episodes per year)
• Suspected complications (orbital cellulitis, meningitis, intracranial involvement)
• Need to clarify allergic or immunologic basis
• Chronic sinusitis with nasal polyps after failed medical therapy
• Anatomical abnormalities requiring surgical evaluation

Patients with recurrent or chronic sinusitis should be evaluated for underlying inflammation, allergic rhinitis, immunodeficiency, and anatomic abnormalities. 4, 3

Critical Pitfalls to Avoid

Do not prescribe antibiotics for viral rhinosinusitis lasting <10 days unless severe symptoms are present—this contributes to antimicrobial resistance without clinical benefit. 1, 6

Never use systemic corticosteroids without antibiotics when bacterial sinusitis is suspected—this may suppress immune response and allow bacterial proliferation. 3

Reassess patients at 72 hours (pediatrics) or 3-5 days (adults)—continuing ineffective therapy beyond this timepoint leads to treatment failure and complications. 3

Reserve fluoroquinolones as second-line therapy—overuse promotes resistance development; use only for treatment failures, complicated sinusitis, or severe penicillin allergy. 1, 3

Complete the full antibiotic course even after symptoms improve—inadequate treatment duration leads to relapse. 2, 3