What is the treatment for sinusitis?

Treatment of Sinusitis

Distinguish Viral from Bacterial Sinusitis First

Most acute rhinosinusitis (98-99.5%) is viral and resolves spontaneously within 7-10 days without antibiotics—reserve antibiotics only for confirmed bacterial sinusitis meeting specific diagnostic criteria. 1, 2

Antibiotics should only be initiated when one of three clinical patterns confirms bacterial infection: 1, 3

• 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 1, 3
• High-dose therapy (for 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:

Continue antibiotics until symptom-free for 7 days, typically 10-14 days total. 4, 3

Second-Line Treatment for Antibiotic Failure

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

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

This provides coverage against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis, as well as drug-resistant Streptococcus pneumoniae. 4, 3

Penicillin-Allergic Patients

For documented penicillin allergy, second- or third-generation cephalosporins are the preferred alternatives. 1, 3

Non-severe penicillin allergy (rash, mild reactions):

• Cefuroxime (second-generation cephalosporin) 3
• Cefpodoxime, cefdinir, or cefprozil (third-generation cephalosporins) 1, 3

The risk of cross-reactivity between penicillins and second/third-generation cephalosporins is negligible. 3

Severe beta-lactam allergy (anaphylaxis):

• Levofloxacin 500 mg once daily for 10-14 days 3
• Moxifloxacin 400 mg once daily for 10 days 3

Critical caveat: Azithromycin and other macrolides should NOT be used as first-line therapy due to resistance rates of 20-25% for both S. pneumoniae and H. influenzae. 3

Adjunctive Therapies (Essential for All Patients)

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

• Fluticasone propionate: 100-200 mcg daily (1-2 sprays per nostril once daily) 5
• Mometasone furoate or budesonide: equivalent dosing 1

Maximum benefit may take several days, with some patients experiencing improvement within 12 hours. 5

Additional supportive measures: 1, 2

• Analgesics (acetaminophen, NSAIDs) for pain and fever
• Saline nasal irrigation (high-volume daily irrigation for chronic sinusitis)
• Adequate hydration
• Warm facial packs
• Sleeping with head elevated

Important pitfall: Decongestants provide symptomatic relief but have limited evidence for efficacy and should not be used long-term. 1

Chronic Sinusitis Management (Symptoms >8 Weeks)

Chronic sinusitis requires a different treatment approach focused on inflammation control rather than infection. 1, 2

First-line therapy: 1, 2

• Intranasal corticosteroids (primary treatment)
• Daily high-volume saline irrigation
• Longer duration antibiotic therapy (minimum 3 weeks) if infectious component present

For chronic infectious sinusitis:

Continue antibiotics for 21-28 days, using broader-spectrum agents like high-dose amoxicillin-clavulanate, cefuroxime, or cefpodoxime with or without anaerobic coverage (clindamycin or metronidazole). 4

For nasal polyps:

Consider a short course of systemic corticosteroids or doxycycline 100 mg daily for 20-21 days. 2, 3

When to Refer to a Specialist

Refer patients to an otolaryngologist or allergist/immunologist in the following situations: 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 surgical intervention

Underlying conditions requiring specialist evaluation: 4, 2

• Allergic rhinitis - evaluate for IgE sensitization to inhalant allergens
• Immunodeficiency - measure quantitative serum IgG, IgA, IgM levels and specific antibody responses
• Anatomical abnormalities - consider CT scan if not already done

Critical Pitfalls to Avoid

Do not prescribe antibiotics for viral rhinosinusitis lasting <10 days unless severe symptoms are present. 1, 3 This contributes to antimicrobial resistance without clinical benefit, as the number needed to treat with antibiotics is only 3-5 for persistent symptoms. 3

Reassess patients at 3-5 days: If no improvement, switch antibiotics or re-evaluate diagnosis. 4, 3 Do not continue ineffective therapy beyond this timepoint.

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

Complete the full course of antibiotics even after symptoms improve to prevent relapse. 2, 3

Failure to address underlying factors (allergies, anatomical abnormalities, immunodeficiency) leads to recurrent or chronic sinusitis requiring specialist evaluation. 4, 2