Initial Treatment for Acute Maxillary Sinusitis
Start with amoxicillin 500 mg twice daily (or 875 mg twice daily for more severe infections) for 10-14 days as first-line therapy. 1, 2
Diagnostic Confirmation
Before initiating treatment, confirm the diagnosis based on clinical criteria:
- Purulent rhinorrhea (anterior and/or posterior, often unilateral) with pain upon pressure over the maxillary sinus 1
- Unilateral infraorbital pain that worsens when bending forward, often pulsatile and peaking in early evening/night 1
- Symptoms present for less than 4 weeks (defines acute sinusitis) 1
Imaging is generally not necessary for diagnosis—plain radiographs have significant false-positive and false-negative results. 1 Reserve CT imaging for suspected complications or treatment failures. 1
First-Line Antibiotic Therapy
Standard Approach
Amoxicillin remains the drug of choice due to effectiveness, low cost, and tolerability: 1, 2
- Dosing: 500 mg twice daily for standard cases; 875 mg twice daily for more severe infections 2
- Duration: Continue until patient is well for 7 days (typically 10-14 days total) 1, 2
- Reassess at 3-5 days: If symptoms are improving, continue the same antibiotic; if no improvement, switch to second-line therapy 1
Alternative First-Line Options (for penicillin allergy)
For patients with penicillin allergy, use: 1, 2
- Cephalosporins: Cefuroxime-axetil, cefpodoxime-proxetil, cefdinir 1, 2
- Pristinamycin (particularly for beta-lactam allergy) 1, 2
- Duration: 7-10 days (some cephalosporins effective in 5 days) 1, 2
Do NOT use azithromycin due to significant resistance patterns in Streptococcus pneumoniae and Haemophilus influenzae. 2
Second-Line Therapy (Treatment Failure)
If no improvement after 3-5 days, switch to: 1
- High-dose amoxicillin-clavulanate: 90 mg/kg amoxicillin with 6.4 mg/kg clavulanate (not exceeding 2 g every 12 hours) 1, 2
- Alternative: Cefuroxime axetil 1
- For complicated cases or frontal/ethmoidal/sphenoidal involvement: Consider respiratory fluoroquinolones (levofloxacin 500 mg daily for 10-14 days or 750 mg daily for 5 days; moxifloxacin) 1, 3
Adjunctive Therapies
Nasal Corticosteroids
Intranasal corticosteroids are helpful as adjunctive therapy: 1, 2, 4
- Use budesonide 200 mcg in each nostril once daily for 10 days 5
- Particularly beneficial in patients with marked mucosal edema or nasal polyposis 1
Oral Corticosteroids
Short-term oral corticosteroids may be reasonable when: 1, 2
- Patient fails initial antibiotic therapy
- Marked mucosal edema present
- Nasal polyposis demonstrated
- Severe pain (acute hyperalgic sinusitis) 2
Supportive Measures
Recommend comfort measures: 1
- Adequate rest and hydration
- Analgesics as needed
- Warm facial packs, steamy showers
- Sleep with head of bed elevated
Critical Red Flags Requiring Immediate Referral
Screen for complications that require hospitalization and parenteral antibiotics: 1
- Meningeal signs
- Exophthalmos or palpebral edema
- Abnormal extraocular movements or visual changes
- Periorbital inflammation/edema/erythema
- Severe pain preventing sleep
- Facial swelling or erythema over involved sinus
Special Considerations
Dental Origin
For unilateral maxillary sinusitis with upper unilateral dental infection: 1
- Antibiotics are definitely indicated
- Consider amoxicillin-clavulanate or pristinamycin for broader anaerobic coverage 1
- Dental care and possible sinus puncture/meatomy may be required 6
Treatment Monitoring
Instruct patients to contact you if: 1
- Symptoms worsen (especially headache or high fever)
- No improvement within 3-5 days of treatment
- Emphasize completing the full antibiotic course even after symptom improvement to prevent relapse 1, 2
Common Pitfalls to Avoid
- Do not routinely order imaging—diagnosis is clinical 1
- Do not use trimethoprim-sulfamethoxazole in children due to higher resistance rates 1
- Reserve fluoroquinolones for treatment failures or complicated sinusitis (frontal, ethmoidal, sphenoidal) 1, 2
- Avoid macrolides (azithromycin, erythromycin) due to resistance 2