What is the treatment for acute sinusitis?

Treatment of Acute Sinusitis

Initial Management: Symptomatic Treatment First

Most cases of acute sinusitis should begin with symptomatic management using analgesics, nasal saline irrigation, and decongestants, reserving antibiotics only for specific clinical scenarios. 1

Symptomatic Treatment (All Patients)

• Analgesics (acetaminophen or NSAIDs) should be offered for pain relief 1
• Saline nasal irrigation promotes mucus clearance and temporarily reduces tissue edema 1
• Topical nasal decongestants may be used short-term (≤3-5 days) to relieve nasal congestion, but prolonged use leads to rebound congestion 1
• Intranasal corticosteroids provide modest but clinically important benefits (number needed to treat = 14) and should be considered for all patients 1

When to Start Antibiotics

Antibiotics should only be initiated when acute bacterial sinusitis is confirmed by one of three specific clinical patterns: 1, 2

1. Persistent symptoms ≥10 days without clinical improvement (nasal discharge, congestion, facial pain/pressure, or cough) 1
2. Severe symptoms for ≥3-4 consecutive days (fever ≥39°C, purulent nasal discharge, and facial pain) 1
3. "Double sickening" - worsening symptoms after initial improvement from a viral upper respiratory infection 1

Most acute rhinosinusitis cases are viral and resolve spontaneously within 7 days without antibiotics. 2

First-Line Antibiotic Selection

Standard First-Line Choice

Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days is the preferred first-line antibiotic for acute bacterial sinusitis in adults. 2

• Plain amoxicillin 500 mg twice daily (mild disease) or 875 mg twice daily (moderate disease) remains acceptable for uncomplicated cases without recent antibiotic exposure 2
• The clavulanate component provides essential coverage against β-lactamase-producing H. influenzae and M. catarrhalis, which have become increasingly prevalent 2

Pediatric Dosing

• Standard therapy: Amoxicillin 45 mg/kg/day in 2 divided doses 2
• High-dose therapy: Amoxicillin 80-90 mg/kg/day in 2 divided doses for areas with high prevalence of resistant S. pneumoniae or children with risk factors (age <2 years, daycare attendance, recent antibiotic use) 2
• Amoxicillin-clavulanate: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses for high-risk children 2

Treatment Duration

Treat for 5-10 days, with most guidelines recommending treatment until symptom-free for 7 days (typically 10-14 days total). 1, 2

• Shorter 5-7 day courses have comparable efficacy with fewer side effects 2

Penicillin-Allergic Patients

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

Recommended Options

• Second-generation: Cefuroxime-axetil 2
• Third-generation: Cefpodoxime-proxetil, cefdinir, or cefprozil (superior activity against H. influenzae) 2
• Severe beta-lactam allergy: Levofloxacin 500 mg once daily for 10-14 days (adults only) 2

Critical caveat: Doxycycline 100 mg once daily for 10 days is acceptable but suboptimal, with a 20-25% predicted bacteriologic failure rate due to limited activity against H. influenzae. 2 It should not be used in children <8 years old due to tooth enamel discoloration risk. 2

Azithromycin and other macrolides should NOT be used as first-line therapy due to 20-25% resistance rates. 2

Treatment Failure Protocol

If no improvement occurs within 3-5 days (adults) or 72 hours (pediatrics), reassess the diagnosis and switch antibiotics. 1, 2

Second-Line Options

• High-dose amoxicillin-clavulanate (4 g/250 mg per day) 2
• Respiratory fluoroquinolones (levofloxacin 500-750 mg once daily or moxifloxacin) provide 90-92% predicted clinical efficacy and excellent coverage against multi-drug resistant S. pneumoniae 2, 3
• Fluoroquinolones should be reserved for treatment failures, complicated sinusitis (frontal, ethmoidal, or sphenoidal involvement), or multi-drug resistant organisms to prevent resistance development 1, 2

Adjunctive Therapies

• Intranasal corticosteroids are beneficial as adjunct to antibiotic therapy, especially when marked mucosal edema is present 1, 2
• Short-term oral corticosteroids (e.g., dexamethasone 4 mg) may be considered for acute hyperalgic sinusitis (severe pain) or patients who fail to respond to initial treatment 2
• Guaifenesin has theoretical benefits but insufficient evidence in sinusitis 1
• Antihistamines should be avoided unless the patient has concurrent allergic rhinitis, as they may thicken secretions 1

Watchful Waiting Option

For adults with uncomplicated acute bacterial sinusitis, watchful waiting without immediate antibiotics is appropriate when follow-up can be assured, with antibiotics started if no improvement by 7 days or worsening at any time. 2

The number needed to treat with antibiotics for persistent symptoms is 3-5. 2

Critical Pitfalls to Avoid

• Overdiagnosis of bacterial sinusitis leading to unnecessary antibiotic use - most cases are viral 1
• Using antihistamines in non-allergic patients, which thickens secretions 1
• Prolonged topical decongestant use (>3-5 days) causes rebound congestion 1
• Inadequate treatment duration leads to relapse - ensure minimum 5 days, typically 7-10 days 2
• Routine fluoroquinolone use as first-line therapy promotes resistance 2
• Failure to recognize complications requiring urgent intervention (orbital cellulitis, intracranial extension) - these require immediate specialist consultation and imaging 1

When to Refer to a Specialist

• Sinusitis refractory to standard antibiotic treatment 1
• Recurrent sinusitis (≥3 episodes per year) - evaluate for underlying inflammation, allergy, immunodeficiency, or anatomic abnormalities 1, 2
• Complications such as orbital or intracranial involvement 1
• Need to clarify allergic or immunologic basis for sinusitis 2