What is the treatment for sinusitis?

Treatment of Sinusitis

First-Line Antibiotic Selection

Amoxicillin-clavulanate is the preferred first-line antibiotic for acute bacterial sinusitis in both adults and children, not amoxicillin alone. 1, 2

• For adults, the recommended dose is amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days 1, 2
• For children, use high-dose amoxicillin-clavulanate 80-90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses, particularly in areas with high prevalence of resistant S. pneumoniae or in children with risk factors (age <2 years, daycare attendance, recent antibiotic use) 1, 3
• The clavulanate component provides essential coverage against β-lactamase-producing H. influenzae and M. catarrhalis, which have become increasingly prevalent 3

The rationale for preferring amoxicillin-clavulanate over plain amoxicillin is the increasing bacterial resistance patterns, with 20-25% of H. influenzae and M. catarrhalis now producing β-lactamases 1, 3. Plain amoxicillin (500 mg twice daily for mild disease or 875 mg twice daily for moderate disease) remains acceptable only for uncomplicated cases without recent antibiotic exposure 3.

Treatment Duration

• Adults: 5-10 days for uncomplicated acute bacterial sinusitis, with most guidelines recommending treatment until symptom-free for 7 days 1, 2
• Children: 10-14 days 3, 2
• Shorter 5-7 day courses have comparable efficacy with fewer side effects 3

Penicillin-Allergic Patients

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

• Second-generation: Cefuroxime-axetil 1, 3
• Third-generation: Cefpodoxime-proxetil, cefdinir, or cefprozil 1, 3
• Recent evidence shows the risk of serious allergic reactions to second- and third-generation cephalosporins in penicillin-allergic patients is negligible 3

For severe beta-lactam allergy (Type I hypersensitivity/anaphylaxis): Reserve respiratory fluoroquinolones (levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily) for 10-14 days 3, 4

Critical Pitfall to Avoid

Do not use azithromycin or other macrolides for acute bacterial sinusitis due to resistance rates exceeding 20-25% for both S. pneumoniae and H. influenzae 1, 3, 2. The American Academy of Pediatrics explicitly states azithromycin should not be used, even in penicillin-allergic patients 3.

Second-Line Treatment for Treatment Failure

If no improvement occurs within 3-5 days (adults) or 72 hours (children), reassess and switch antibiotics 1, 3:

Primary second-line option: Respiratory fluoroquinolones

• Levofloxacin 500-750 mg once daily for 10 days 1, 3, 4
• Moxifloxacin 400 mg once daily for 10 days 1, 3
• These provide 90-92% predicted clinical efficacy and excellent coverage against multi-drug resistant S. pneumoniae (MDRSP) and β-lactamase-producing organisms 3, 4

Alternative second-line option: High-dose amoxicillin-clavulanate (4 g amoxicillin/250 mg clavulanate per day) for 10-14 days 3

When to Use Fluoroquinolones

Fluoroquinolones should be reserved for specific situations to prevent resistance development 1, 3, 2:

• Treatment failure with first-line antibiotics
• Severe beta-lactam allergy
• Complicated sinusitis (frontal, ethmoidal, or sphenoidal involvement)
• Multi-drug resistant S. pneumoniae
• Never use as routine first-line therapy 1, 2

Adjunctive Therapies

Intranasal corticosteroids are recommended as adjuncts to antibiotic therapy in both acute and chronic sinusitis 1, 3, 2:

• Particularly beneficial in patients with allergic rhinitis 2
• Help reduce mucosal inflammation and promote drainage 1

Short-term oral corticosteroids may be considered for 1, 3:

• Acute hyperalgic sinusitis (severe pain)
• Marked mucosal edema
• Patients who fail to respond to initial treatment
• Typical duration: 5 days 1

Supportive measures 3:

• Adequate hydration
• Analgesics (acetaminophen, NSAIDs) for pain 3
• Intranasal saline irrigation 2
• Warm facial packs 3
• Sleeping with head elevated 3

Decongestants (topical or oral) may help decrease nasal resistance and improve sinus ventilation, but avoid prolonged use of topical decongestants (>3-5 days) to prevent rebound congestion (rhinitis medicamentosa) 1

Antihistamines are not recommended for acute bacterial sinusitis, but may be beneficial in chronic sinusitis if the underlying risk factor is allergic rhinitis 1, 3

Chronic and Recurrent Sinusitis

Recurrent sinusitis is defined as 3 or more episodes of acute sinusitis per year 5, 1

Chronic sinusitis is defined as signs and symptoms persisting 8 weeks or longer 5

Patients with chronic or recurrent sinusitis should be evaluated for 5, 1:

• Underlying inflammation and allergies (test for IgE sensitization to inhalant allergens)
• Immunodeficiency (measure quantitative serum IgG, IgA, IgM levels and assess specific antibody responses)
• Anatomic abnormalities (consider sinus CT scan)
• Nasal polyps

Consider consultation with:

• Allergist-immunologist for treatment of underlying allergic factors, evaluation of unusual pathogens, and immunodeficiency 5
• Otolaryngologist for structural abnormalities, obstructing nasal polyps, or sinusitis refractory to medical management 5, 3

For chronic hyperplastic eosinophilic rhinosinusitis: This does not respond to antibiotics and is marked by eosinophils and mixed mononuclear cells. A course of systemic corticosteroids may be necessary 5

Diagnostic Confirmation Before Treatment

Antibiotics should only be initiated when acute bacterial sinusitis is confirmed by one of three clinical patterns 3, 2:

1. Persistent symptoms: ≥10 days without clinical improvement (nasal symptoms or cough) 3, 2
2. Severe symptoms: High fever (>39°C) and purulent nasal discharge for ≥3 consecutive days 3, 2
3. "Double sickening": Worsening symptoms after initial improvement from a viral URI 3, 2

Most acute rhinosinusitis cases are viral and resolve without antibiotics within 7 days 3. Do not treat viral rhinosinusitis with antibiotics 1.

Watchful Waiting Option

For adults with uncomplicated acute bacterial sinusitis, watchful waiting without antibiotics is an appropriate initial strategy when follow-up can be assured, with antibiotics started if no improvement by 7 days or worsening at any time 3. The number needed to treat with antibiotics is 3-5 for persistent symptoms 3.

Critical Pitfalls Summary

• Never use fluoroquinolones as first-line therapy - reserve for treatment failures, severe disease, or complicated sinusitis 1, 2
• Never use azithromycin or macrolides due to 20-25% resistance rates 3, 2
• Avoid prolonged topical decongestants (>3-5 days) to prevent rhinitis medicamentosa 1
• Ensure adequate treatment duration (minimum 5 days, typically 7-10 days for adults, 10-14 days for children) to prevent relapse 1, 3
• Reassess at 3-5 days (adults) or 72 hours (children) if no improvement 1, 3
• Complete the full course of antibiotics even after symptoms improve to prevent relapse 3
• Evaluate for underlying causes in chronic or recurrent sinusitis 5, 1