What is the treatment for sinusitis?

Treatment of Sinusitis

Distinguish Viral from Bacterial Sinusitis First

Antibiotics should only be initiated when acute bacterial sinusitis is confirmed by one of three clinical patterns: persistent symptoms ≥10 days without clinical improvement, severe symptoms (fever ≥39°C with purulent nasal discharge and facial pain) for ≥3 consecutive days, or "double sickening"—worsening symptoms after initial improvement from a viral upper respiratory infection. 1, 2

• 98-99.5% of acute rhinosinusitis is viral and resolves spontaneously within 7-10 days without antibiotics 1, 2
• Wait at least 10 days before considering antibiotics unless severe symptoms are present 1, 3
• Mucus color alone does not indicate bacterial infection—color reflects neutrophils, not bacteria 1

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, 3

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 3

Treatment Duration:

• Continue until symptom-free for 7 days (typically 10-14 days total) 4, 3
• Reassess at 72 hours (pediatrics) or 3-5 days (adults)—if no improvement, switch antibiotics 3

Second-Line Treatment for Amoxicillin Failure

For patients who fail initial amoxicillin therapy after 72 hours to 5 days, switch to high-dose amoxicillin-clavulanate. 4, 3

• Adult dosing: 875 mg/125 mg twice daily or 2000 mg/125 mg twice daily for 10-14 days 3
• Pediatric dosing: 90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 3
• The clavulanate component provides coverage against β-lactamase-producing H. influenzae and M. catarrhalis 3

Penicillin-Allergic Patients

For documented penicillin allergy, second- or third-generation cephalosporins are the preferred alternatives. 3

Non-severe/delayed-type allergy (rash):

• Cefuroxime-axetil (second-generation) 3
• Cefpodoxime-proxetil or cefdinir (third-generation, superior activity against H. influenzae) 3
• Risk of cross-reactivity with penicillin allergy is negligible 3

Severe/Type I hypersensitivity (anaphylaxis):

• Levofloxacin 500 mg once daily for 10-14 days 3
• Moxifloxacin 400 mg once daily for 10 days 3
• Reserve fluoroquinolones for true severe allergies to prevent resistance 3

What NOT to use:

• Azithromycin and macrolides are contraindicated due to 20-25% resistance rates for S. pneumoniae and H. influenzae 3
• Trimethoprim-sulfamethoxazole has high resistance rates (50% for S. pneumoniae, 27% for H. influenzae) 3

Adjunctive Therapies for All Patients

Intranasal corticosteroids are recommended as adjunctive therapy in both acute and chronic sinusitis to reduce inflammation and improve drainage. 4, 1, 3

Intranasal Corticosteroids:

• Fluticasone propionate: 200 mcg/day (2 sprays per nostril once daily) for adults; 100 mcg/day (1 spray per nostril once daily) for children ≥4 years 5
• Mometasone or budesonide are equally effective alternatives 1
• Maximum benefit may take several days; some symptom relief occurs within 12 hours 5
• Continue for duration of antibiotic therapy and beyond to maintain mucosal health 4

Supportive Measures:

• Analgesics (acetaminophen, NSAIDs) for pain relief 1, 3
• Saline nasal irrigation (high-volume, daily) for symptomatic relief and improved mucociliary clearance 1, 2
• Adequate hydration 1, 3
• Warm facial packs and sleeping with head elevated 1, 3
• Decongestants (pseudoephedrine or topical oxymetazoline for ≤3 days) provide symptomatic relief but have limited evidence for efficacy 1

Systemic Corticosteroids (Short-term):

• Consider oral prednisone or dexamethasone 4 mg for 5 days in patients with marked mucosal edema, nasal polyps, or failure to respond to initial treatment 4, 3
• Never give systemic corticosteroids without antibiotics when bacterial sinusitis is suspected—this may suppress immune response and allow bacterial proliferation 3

Chronic Sinusitis Management (Symptoms >8 Weeks)

Chronic sinusitis requires longer antibiotic courses (minimum 3 weeks), intranasal corticosteroids as first-line therapy, and daily high-volume saline irrigation. 1, 2

• Evaluate for underlying inflammation, allergy, immunodeficiency, and anatomic abnormalities 4, 2, 3
• Consider 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, 3

• Sinusitis refractory to two courses of appropriate antibiotics 1
• Recurrent sinusitis (≥3 episodes per year) 4, 2, 3
• Suspected complications (orbital cellulitis, meningitis, intracranial involvement) 1
• Need to clarify allergic or immunologic basis 3
• Chronic sinusitis with nasal polyps, anatomic abnormalities, or ostiomeatal obstruction despite aggressive medical management 4

Critical Pitfalls to Avoid

• Do not prescribe antibiotics for viral rhinosinusitis lasting <10 days—this contributes to antimicrobial resistance without clinical benefit 1, 2
• Complete the full antibiotic course even after symptoms improve to prevent relapse 2, 3
• Reassess at 72 hours (pediatrics) or 3-5 days (adults)—do not continue ineffective therapy beyond this timepoint 3
• Avoid fluoroquinolone overuse—reserve for treatment failures, severe disease, or true penicillin allergy to prevent resistance 3
• Never use clindamycin as monotherapy—it lacks activity against H. influenzae and M. catarrhalis 3