What is the treatment for acute sinusitis?

Treatment of Acute Sinusitis

Most cases of acute sinusitis should be managed initially with symptomatic treatment alone (analgesics, nasal saline irrigation, and decongestants), reserving antibiotics for patients with severe symptoms, persistent symptoms beyond 10-14 days without improvement, or worsening symptoms after initial improvement. 1

Initial Diagnostic Approach

Acute sinusitis is defined as symptoms lasting less than 4 weeks 1, 2. Before initiating treatment, distinguish between viral and bacterial causes:

• Viral rhinosinusitis accounts for the majority of cases and resolves spontaneously within 7-10 days 3
• Bacterial sinusitis should be suspected in three specific scenarios:
  • Persistent symptoms ≥10 days without improvement 1, 2
  • Severe symptoms (fever >39°C, purulent nasal discharge, facial pain) for ≥3 consecutive days 1, 2
  • "Double sickening" - worsening after initial improvement from a viral URI 1, 2

First-Line Symptomatic Management

All patients should receive symptomatic treatment regardless of whether antibiotics are prescribed: 1

• Analgesics: Acetaminophen or NSAIDs for pain relief 1
• Nasal saline irrigation: Promotes mucus clearance and reduces tissue edema 1
• Topical nasal decongestants: Short-term use only (≤3-5 days) to avoid rebound congestion 1
• Intranasal corticosteroids: Provide modest but clinically important benefits with a number needed to treat of 14 1, 2

Antibiotic Therapy: When and What to Prescribe

Indications for Antibiotics

Reserve antibiotics for patients meeting bacterial sinusitis criteria outlined above 1, 2. The number needed to treat with antibiotics is 3-5 for persistent symptoms 2.

First-Line Antibiotic Choices

For uncomplicated maxillary sinusitis without recent antibiotic exposure:

• Amoxicillin 500 mg twice daily (mild disease) or 875 mg twice daily (moderate disease) for 5-10 days 1, 2
• High-dose amoxicillin 80-90 mg/kg/day in adults for areas with high prevalence of resistant S. pneumoniae 2

For patients with risk factors (recent antibiotic use, severe disease, or high local resistance):

• Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days provides better coverage against resistant bacteria 1, 2

Treatment Duration

• Standard duration: 5-10 days, with most guidelines recommending treatment until symptom-free for 7 days (typically 10-14 days total) 1, 2
• Shorter courses (5-7 days) have comparable efficacy with fewer side effects 2, 4

Penicillin-Allergic Patients

For documented penicillin allergy, second- or third-generation cephalosporins are preferred first-line alternatives due to negligible cross-reactivity risk: 2

• Second-generation: Cefuroxime-axetil 1, 2
• Third-generation: Cefpodoxime-proxetil or cefdinir 1, 2

For severe beta-lactam allergy:

• Doxycycline 100 mg once daily for 10 days (adults only, not for children <8 years) 2
• Levofloxacin 500-750 mg once daily for 5-10 days (reserved for treatment failures or severe disease) 2, 5

Avoid azithromycin due to 20-25% resistance rates among S. pneumoniae and H. influenzae 2, 6

Special Anatomic Considerations

For frontal, ethmoidal, or sphenoidal sinusitis (higher risk of complications):

• Consider respiratory fluoroquinolones (levofloxacin 500-750 mg daily or moxifloxacin) as first-line therapy due to superior penetration and coverage 1, 2
• These sites require more aggressive initial treatment given potential for serious complications 2

Treatment Failure Protocol

If no improvement after 3-5 days of initial antibiotic therapy: 1, 2

• Switch to a different antibiotic class
• Consider amoxicillin-clavulanate (high-dose: 4 g/250 mg per day) if not already used 2
• Consider respiratory fluoroquinolones (levofloxacin or moxifloxacin) for broader coverage against resistant pathogens 1, 2
• Levofloxacin demonstrates 90-92% predicted clinical efficacy and 100% microbiologic eradication for S. pneumoniae, including multi-drug resistant strains 2, 5

Adjunctive Therapies

• Intranasal corticosteroids: Beneficial as adjunct to antibiotics, especially with marked mucosal edema 1, 2
• Short-term oral corticosteroids: May be considered for patients with severe pain (acute hyperalgic sinusitis) or marked mucosal edema who fail initial treatment 1, 2
• Avoid antihistamines unless concurrent allergic rhinitis is present, as they may thicken secretions 1
• Guaifenesin: Insufficient evidence to support routine use 1

Pediatric Dosing

• Amoxicillin: 45 mg/kg/day in 2 divided doses (standard) or 80-90 mg/kg/day (high-dose for resistant organisms) 2
• Amoxicillin-clavulanate: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses for children with risk factors (age <2 years, daycare attendance, recent antibiotic use) 2
• Cefpodoxime proxetil: 8 mg/kg/day in two doses for penicillin-allergic children 2

Critical Pitfalls to Avoid

• Overdiagnosis of bacterial sinusitis leading to unnecessary antibiotic use - most cases are viral 1, 2
• Prolonged topical decongestant use (>3-5 days) causes rebound congestion 1
• Using antihistamines in non-allergic patients thickens secretions and worsens symptoms 1
• Inadequate treatment duration leads to relapse - complete the full antibiotic course even after symptom improvement 2
• Fluoroquinolone overuse - reserve for treatment failures, severe disease, or complicated sinusitis to prevent resistance 2
• Failure to recognize complications requiring urgent intervention: orbital cellulitis, intracranial extension, epidural/subdural empyema, brain abscess, or cavernous sinus thrombosis 1, 7

When to Refer to a Specialist

Consider specialist consultation for: 1, 2

• Sinusitis refractory to standard antibiotic treatment
• Recurrent sinusitis (≥3 episodes per year)
• Complications such as orbital or intracranial involvement
• Need to evaluate for underlying factors: allergic rhinitis, immunodeficiency, or anatomical abnormalities