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

• Most acute rhinosinusitis (98-99.5%) is viral and resolves spontaneously within 7-10 days without antibiotics 1, 3
• 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
• Continue treatment until symptom-free for 7 days 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

Second-Line Treatment for Antibiotic Failure

If no improvement after 3-5 days of amoxicillin, switch to high-dose amoxicillin-clavulanate. 1, 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
• Amoxicillin-clavulanate provides coverage against β-lactamase-producing H. influenzae and M. catarrhalis, as well as drug-resistant S. pneumoniae 3

Treatment for Penicillin-Allergic Patients

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

• Second-generation: Cefuroxime-axetil 3
• Third-generation: Cefpodoxime-proxetil, cefdinir, or cefprozil 1, 3
• The risk of cross-reactivity between penicillins and second/third-generation cephalosporins is negligible 3

For severe beta-lactam allergy or treatment failure, use respiratory fluoroquinolones. 1, 3

• Levofloxacin: 500 mg once daily for 10-14 days 3
• Moxifloxacin: 400 mg once daily for 10 days 3
• Reserve fluoroquinolones for treatment failures or severe allergies to prevent resistance development 1, 3

What NOT to Use:

• Azithromycin and macrolides are contraindicated due to resistance rates of 20-25% for S. pneumoniae and H. influenzae 1, 3
• Trimethoprim-sulfamethoxazole has high resistance rates (50% for S. pneumoniae, 27% for H. influenzae) 3

Adjunctive Therapies (Use in ALL Patients)

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

• 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 4
• Mometasone furoate or budesonide are equally effective alternatives 1
• Maximum benefit may take several days; some symptom relief occurs within 12 hours 4

Additional Supportive Measures:

• Analgesics (acetaminophen, NSAIDs) for pain relief 1, 3
• Saline nasal irrigation (high-volume daily irrigation for chronic sinusitis) 1, 2
• Adequate hydration, warm facial packs, sleeping with head elevated 1
• Decongestants (pseudoephedrine or topical oxymetazoline for ≤3 days) provide symptomatic relief but have limited evidence for efficacy 1, 5

Short-Term Oral Corticosteroids:

• Consider for patients with marked mucosal edema, nasal polyps, or failure to respond to initial treatment 3
• Never give systemic corticosteroids without antibiotics when bacterial sinusitis is suspected, as this may suppress immune response and allow bacterial proliferation 3

Chronic Sinusitis Management (Symptoms ≥8 Weeks)

Intranasal corticosteroids are first-line therapy for chronic sinusitis. 1, 2

• Daily high-volume saline irrigation is essential 1, 2
• Longer duration antibiotic therapy (minimum 3 weeks) may be required for chronic infectious sinusitis 1, 2
• Consider a short course of systemic corticosteroids or doxycycline for patients with nasal polyps 2
• Chronic hyperplastic eosinophilic rhinosinusitis does not respond to antibiotics and may require systemic corticosteroids 6

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
• Evaluation for anatomical abnormalities or nasal polyps requiring surgery

Evaluate for Underlying Risk Factors in Recurrent Cases:

• Allergic rhinitis: Test for IgE sensitization to inhalant allergens; treat with environmental control, pharmacotherapy, and allergen immunotherapy 6
• Immunodeficiency: Measure quantitative serum IgG, IgA, IgM levels and assess specific antibody responses 6
• Anatomical abnormalities: Consider CT scan if not already done; evaluate for septal deviation, middle turbinate deformity, or obstructing nasal polyps 6

Critical Pitfalls to Avoid

• Do not prescribe antibiotics for viral rhinosinusitis lasting <10 days—this contributes to antimicrobial resistance without clinical benefit 1, 3
• Reassess patients at 3-5 days (adults) or 72 hours (pediatrics) if no improvement; do not continue ineffective therapy 3
• Complete the full antibiotic course even after symptoms improve to prevent relapse 2, 3
• Avoid fluoroquinolone overuse—reserve for treatment failures or severe disease to prevent resistance 1, 3
• Never use clindamycin as monotherapy for sinusitis—it lacks activity against H. influenzae and M. catarrhalis 3