What is the recommended management for a patient with bacterial sinusitis?

Management of Bacterial Sinusitis

For adults with acute bacterial sinusitis, amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days is the first-line antibiotic treatment, combined with intranasal corticosteroids to reduce inflammation and improve symptom resolution. 1, 2

Confirm the Diagnosis Before Starting Antibiotics

Before prescribing antibiotics, confirm bacterial sinusitis using one of three clinical patterns: 1, 2

• Persistent symptoms ≥10 days without clinical improvement (nasal congestion, purulent discharge, facial pain) 1
• Severe symptoms for ≥3 consecutive days (fever ≥39°C with purulent nasal discharge) 1
• "Double sickening" - worsening symptoms after initial improvement from a viral upper respiratory infection 1

Critical pitfall: 98-99.5% of acute rhinosinusitis is viral and resolves spontaneously within 7-10 days without antibiotics—do not prescribe antibiotics for symptoms lasting less than 10 days unless severe symptoms are present. 1

First-Line Antibiotic Treatment

Standard dosing for adults: 1, 2

• Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days 1, 2
• Treatment duration: 5-7 days for uncomplicated cases, or until symptom-free for 7 days (typically 10-14 days total) 1, 2

High-dose regimen for specific risk factors: 1

• Amoxicillin-clavulanate 2 g/125 mg twice daily if patient has:
  • Recent antibiotic use within past month 1
  • Age >65 years 1
  • Moderate-to-severe symptoms 1
  • Comorbid conditions or immunocompromised state 1

Pediatric dosing: 1, 2

• High-dose amoxicillin-clavulanate 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 1, 2
• Treatment duration: 10-14 days for children 1, 2

Penicillin-Allergic Patients

For non-severe (non-Type I) penicillin allergy: 1

• Second-generation cephalosporins: cefuroxime-axetil 1
• Third-generation cephalosporins: cefpodoxime-proxetil, cefdinir, or cefprozil 1
• The risk of cross-reactivity with second- and third-generation cephalosporins is negligible 1

For severe penicillin allergy (anaphylaxis/Type I hypersensitivity): 1

• Respiratory fluoroquinolones: levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily for 10 days 1
• These provide 90-92% predicted clinical efficacy against drug-resistant S. pneumoniae and β-lactamase-producing H. influenzae 1

Critical pitfall: Do not use azithromycin or other macrolides as first-line therapy due to resistance rates exceeding 20-25% for both S. pneumoniae and H. influenzae. 1, 3

Essential Adjunctive Therapies

Intranasal corticosteroids (strongly recommended): 1, 2

• Mometasone, fluticasone, or budesonide twice daily 1
• Reduces mucosal inflammation and improves symptom resolution 1
• Strong evidence from multiple randomized controlled trials 1

Supportive measures: 1

• High-volume saline nasal irrigation for symptomatic relief 1, 2
• Analgesics (acetaminophen or NSAIDs) for pain and fever 1
• Adequate hydration 1
• Warm facial packs 1
• Sleep with head elevated 1

Short-term oral corticosteroids (selective use): 1

• Consider for patients with marked mucosal edema or who fail to respond to initial treatment 1
• Typical duration: 5 days 1

Treatment Failure Protocol

Reassess at 3-5 days: 1, 2

• If no improvement, switch to second-line antibiotic 1
• For adults initially on amoxicillin-clavulanate: switch to respiratory fluoroquinolone (levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily for 10 days) 1
• For children: switch to high-dose amoxicillin-clavulanate if not already prescribed 1

Reassess at 7 days: 1

• Reconfirm diagnosis if symptoms persist or worsen 1
• Consider imaging (CT scan) only if complications suspected or alternative diagnosis likely 1
• Refer to otolaryngology if no improvement after appropriate second-line therapy 1

Pediatric reassessment at 72 hours: 1, 2

• Switch antibiotics if worsening or no improvement 1, 2
• Consider complications, alternative diagnosis, or ENT referral 1

When to Refer to a Specialist

Refer to otolaryngology or allergist-immunologist for: 1

• Sinusitis refractory to two courses of appropriate antibiotics 1
• Recurrent sinusitis (≥3 episodes per year) 1
• Suspected complications (orbital cellulitis, meningitis, brain abscess) 1
• Need to clarify allergic or immunologic basis 1
• Chronic sinusitis (symptoms >8 weeks) 1

Watchful Waiting Option

For uncomplicated acute bacterial sinusitis in adults with reliable follow-up: 1

• Watchful waiting without immediate antibiotics is appropriate 1
• Start antibiotics only if no improvement by 7 days or symptoms worsen at any time 1
• This approach recognizes that 73% of bacterial sinusitis shows spontaneous improvement by 7-12 days without antibiotics 1

Critical Pitfalls to Avoid

• Do not use first-generation cephalosporins (cephalexin, cefadroxil) due to inadequate coverage against H. influenzae 1
• Do not use fluoroquinolones as routine first-line therapy in patients without documented β-lactam allergies—reserve for treatment failures or severe disease to prevent resistance 1, 2
• Do not use trimethoprim-sulfamethoxazole due to 50% resistance rate for S. pneumoniae 1
• Do not prescribe antibiotics for viral rhinosinusitis lasting <10 days unless severe symptoms present 1
• Ensure adequate treatment duration (minimum 5 days for adults, 10-14 days for children) to prevent relapse 1, 2