What is the treatment for acute sinusitis?

Treatment of Acute Sinusitis

Initial Management: Symptomatic Treatment First

Most cases of acute sinusitis are viral and resolve spontaneously within 7-10 days without antibiotics—start with symptomatic management and reserve antibiotics for specific clinical criteria. 1

Symptomatic Treatment (First-Line for All Patients)

• Analgesics (acetaminophen or NSAIDs) should be offered for pain relief in all patients with acute sinusitis 1
• Saline nasal irrigation promotes mucus clearance and temporarily reduces tissue edema 1
• Intranasal corticosteroids (mometasone, fluticasone, or budesonide twice daily) provide modest but clinically important benefits with a number needed to treat of 14 1, 2
• Topical nasal decongestants may be used short-term (≤3-5 days) to relieve nasal congestion, but prolonged use leads to rebound congestion 1
• Systemic decongestants (pseudoephedrine) provide symptomatic relief, though evidence for efficacy is limited 2

When to Start Antibiotics: Three Clinical Patterns

Antibiotics should be reserved for patients meeting one of these three criteria 1, 2:

1. Persistent symptoms ≥10 days without clinical improvement
2. Severe symptoms for ≥3 consecutive days (fever ≥39°C/102°F with purulent nasal discharge and facial pain)
3. "Double sickening": worsening symptoms after initial improvement from a viral upper respiratory infection

Antibiotic Selection

First-Line Antibiotic Therapy

Amoxicillin is the first-line antibiotic choice for uncomplicated acute bacterial sinusitis due to its effectiveness, low cost, and tolerability. 1

• Standard-dose amoxicillin: 500 mg twice daily for mild disease 3
• High-dose amoxicillin: 875 mg twice daily for moderate disease or areas with high prevalence of resistant S. pneumoniae 3
• Treatment duration: 10-14 days or until symptom-free for 7 days 1, 3

For patients at risk of resistant organisms (recent antibiotic use within 4-6 weeks, age <2 years, daycare attendance), use high-dose amoxicillin-clavulanate 875 mg/125 mg twice daily 1, 3

Penicillin-Allergic Patients

For documented penicillin allergy, second- or third-generation cephalosporins are preferred due to negligible cross-reactivity risk. 3

• Second-generation cephalosporins: Cefuroxime-axetil 3
• Third-generation cephalosporins: Cefpodoxime-proxetil or cefdinir (superior activity against H. influenzae) 3
• For severe beta-lactam allergy: Doxycycline 100 mg once daily for 10 days (adults only, not for children <8 years) 3, 2
• Respiratory fluoroquinolones (levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily for 10 days) should be reserved for severe allergy or treatment failures 3, 4

Critical pitfall: Azithromycin should NOT be used for acute bacterial sinusitis due to resistance rates of 20-25% for S. pneumoniae and H. influenzae 3, 5

Second-Line Therapy for Treatment Failure

If no improvement after 3-5 days of initial antibiotic therapy, switch to a different antibiotic. 1, 3

• High-dose amoxicillin-clavulanate (4 g amoxicillin/250 mg clavulanate per day) for β-lactamase-producing organisms or drug-resistant S. pneumoniae 3
• Respiratory fluoroquinolones (levofloxacin 500-750 mg once daily or moxifloxacin 400 mg once daily) provide 90-92% predicted clinical efficacy against resistant pathogens 3, 4
• Ceftriaxone 1-2 g IM/IV once daily for 5 days for patients unable to tolerate oral medications or with severe disease 3

Adjunctive Therapies

• Intranasal corticosteroids are beneficial as adjunctive therapy, especially when marked mucosal edema is present 1, 3
• Short-term oral corticosteroids (typically 5 days) may be considered for patients who fail initial treatment or have marked mucosal edema 1, 3
• Avoid antihistamines unless the patient has concurrent allergic rhinitis, as they may thicken secretions 1
• Guaifenesin has theoretical benefits but insufficient evidence in sinusitis 1

Pediatric Dosing

• Standard-dose amoxicillin: 45 mg/kg/day in 2 divided doses 3
• High-dose amoxicillin: 80-90 mg/kg/day in 2 divided doses for high-risk children (age <2 years, daycare attendance, recent antibiotic use, or areas with high prevalence of resistant S. pneumoniae) 3
• High-dose amoxicillin-clavulanate: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 3
• Ceftriaxone: 50 mg/kg IM as a single dose for children unable to tolerate oral medication 3

Treatment Monitoring and Reassessment

• Reassess at 72 hours (pediatrics) or 3-5 days (adults): If no improvement, switch antibiotics or re-evaluate diagnosis 3
• Reassess at 7 days: Confirm diagnosis if symptoms persist or worsen 3
• Complete the full antibiotic course even after symptoms improve to prevent relapse 3

When to Refer to a Specialist

Consider referral to otolaryngology for 1, 2:

• Sinusitis refractory to two courses of appropriate antibiotics
• Recurrent sinusitis (≥3 episodes per year)
• Suspected complications (orbital cellulitis, meningitis, intracranial extension, abscess)
• Need to clarify allergic or immunologic basis for sinusitis
• Underlying anatomical abnormalities requiring evaluation

Critical Pitfalls to Avoid

• Overdiagnosis of bacterial sinusitis: 98-99.5% of acute rhinosinusitis is viral and resolves spontaneously—wait at least 10 days before prescribing antibiotics unless severe symptoms are present 1, 2
• Using antihistamines in non-allergic patients, which may thicken secretions 1
• Prolonged use of topical decongestants (>3-5 days), which leads to rebound congestion 1
• Prescribing azithromycin due to high resistance rates 3
• Using clindamycin as monotherapy, as it lacks activity against H. influenzae and M. catarrhalis 3
• Inadequate treatment duration, which can lead to relapse 3
• Failure to recognize complications requiring urgent intervention 1, 2