Sinusitis Treatment
Distinguishing Viral from Bacterial Sinusitis
Most acute sinusitis is viral (98–99.5%) and resolves spontaneously within 7–10 days without antibiotics. 1 Antibiotics should only be prescribed when acute bacterial rhinosinusitis (ABRS) is confirmed by at least one of these three patterns:
- Persistent symptoms ≥10 days without improvement (purulent nasal discharge plus nasal obstruction or facial pain/pressure/fullness) 1
- Severe symptoms ≥3–4 consecutive days with fever ≥39°C (102.2°F), purulent nasal discharge, and facial pain 1
- "Double sickening": initial improvement from a viral upper respiratory infection followed by worsening within 10 days 1
Do not prescribe antibiotics for symptoms lasting <10 days unless the severe criteria above are met. 1
First-Line Antibiotic Therapy
For Patients Without Penicillin Allergy
Amoxicillin-clavulanate 875 mg/125 mg orally twice daily for 5–10 days is the preferred first-line regimen, providing 90–92% predicted clinical efficacy against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 1 The clavulanate component is essential because 30–40% of H. influenzae and 90–100% of M. catarrhalis produce β-lactamase. 1
Treatment duration: Continue for 5–10 days or until symptom-free for 7 consecutive days (typically 10–14 days total). 1 Recent evidence supports shorter 5–7 day courses with comparable efficacy and fewer adverse effects. 1
High-Dose Regimen for Risk Factors
Use high-dose amoxicillin-clavulanate (2 g/125 mg twice daily) when any of these risk factors are present: 1
- Recent antibiotic use (within past 4–6 weeks)
- Age >65 years
- Daycare attendance (or close contact with daycare children)
- Moderate-to-severe symptoms
- Comorbidities (diabetes, chronic cardiac/hepatic/renal disease)
- Immunocompromised state
- Smoking or smoke exposure
For Patients with Penicillin Allergy
Non-Severe (Non-Type I) Penicillin Allergy
Second- or third-generation cephalosporins for 10 days are preferred because cross-reactivity with penicillin is negligible (<1%). 1 Options include:
Severe (Type I/Anaphylactic) Penicillin Allergy
Respiratory fluoroquinolones provide 90–92% predicted efficacy against multidrug-resistant S. pneumoniae and β-lactamase-producing organisms: 1
Reserve fluoroquinolones for severe penicillin allergy or documented treatment failure to limit resistance development. 1
Suboptimal Alternative
Doxycycline 100 mg once daily for 10 days offers lower efficacy (77–81%) with a 20–25% bacteriologic failure rate due to limited H. influenzae coverage. 1 Use only when cephalosporins and fluoroquinolones are contraindicated. Contraindicated in children <8 years due to tooth enamel discoloration risk. 1
Antibiotics to Avoid
- Macrolides (azithromycin, clarithromycin): 20–25% resistance rates in S. pneumoniae and H. influenzae 1
- Trimethoprim-sulfamethoxazole: ~50% resistance in S. pneumoniae and ~27% in H. influenzae 1
- First-generation cephalosporins (cephalexin): inadequate coverage because ~50% of H. influenzae strains produce β-lactamase 1
Essential Adjunctive Therapies (Add to All Patients)
Intranasal Corticosteroids (Strong Evidence)
Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily significantly reduce mucosal inflammation and accelerate symptom resolution. 1 3 This recommendation is supported by strong evidence from multiple randomized controlled trials, including a study showing that adding mometasone furoate nasal spray to antibiotics significantly reduced total symptom scores and individual inflammatory symptoms (headache, congestion, facial pain) compared with antibiotics alone. 3
Saline Nasal Irrigation
Saline nasal irrigation 2–3 times daily provides symptomatic relief and enhances mucus clearance. 1 4
Analgesics
Analgesics (acetaminophen or ibuprofen) are recommended for pain and fever control. 1 4
Decongestants
Oral or topical decongestants may be used; limit topical agents to ≤3 days to avoid rebound congestion. 1
Watchful Waiting Strategy
For adults with uncomplicated ABRS and reliable follow-up, initial observation without antibiotics is appropriate. 1 Start antibiotics only if:
- No improvement by day 7, or
- Symptoms worsen at any time 1
The number needed to treat (NNT) with antibiotics is 10–15 to achieve one additional cure compared with placebo. 1
Monitoring and Reassessment
Early Reassessment (Days 3–5)
If no clinical improvement (persistent purulent drainage, unchanged facial pain, or worsening), switch to: 1
- High-dose amoxicillin-clavulanate (2 g/125 mg twice daily), or
- Respiratory fluoroquinolone (levofloxacin 500 mg daily or moxifloxacin 400 mg daily)
Day 7 Reassessment
Persistent or worsening symptoms require: 1
- Confirmation of ABRS diagnosis
- Exclusion of complications (orbital cellulitis, meningitis, intracranial abscess)
- Imaging only if complications are suspected
- Referral to otolaryngology
Expected Timeline of Recovery
- Noticeable improvement within 3–5 days of appropriate antibiotic therapy 1
- Complete resolution by 10–14 days or when symptom-free for 7 consecutive days 1
- Only 30–41% of patients improve by days 3–5; zero improvement at this stage indicates likely treatment failure 1
Pediatric Considerations
- Standard-dose amoxicillin: 45 mg/kg/day divided twice daily 1
- High-dose amoxicillin: 80–90 mg/kg/day divided twice daily for children <2 years, daycare attendance, or recent antibiotic exposure 1
- High-dose amoxicillin-clavulanate: 80–90 mg/kg/day (amoxicillin component) plus 6.4 mg/kg/day clavulanate divided twice daily 1
- Duration: Minimum 10–14 days (longer than adult courses) 1
- Reassessment: Evaluate at 72 hours; if no improvement, switch to high-dose amoxicillin-clavulanate 1
Referral to Otolaryngology
Refer immediately for any of the following: 1
- No improvement after 7 days of appropriate second-line antibiotic therapy
- Worsening symptoms at any point during treatment
- Suspected complications: severe headache, visual changes, periorbital swelling/erythema, proptosis, diplopia, altered mental status, cranial nerve deficits
- Recurrent sinusitis (≥3 episodes per year) requiring evaluation for underlying allergic rhinitis, immunodeficiency, or anatomic abnormalities
Chronic Sinusitis Management
Chronic rhinosinusitis (CRS) is primarily an inflammatory condition, not an infectious disease. 5 Antibiotics should NOT be routinely prescribed for CRS and should only be used when significant purulent nasal discharge is present on direct examination. 5
First-Line Therapy for Chronic Sinusitis
- Intranasal corticosteroids are the cornerstone of treatment due to their anti-inflammatory effects and documented efficacy 5 6
- Saline nasal irrigation facilitates mechanical removal of mucus and prevents crusting 5 6
When Antibiotics May Be Considered in Chronic Sinusitis
If antibiotics are prescribed for documented purulent exacerbations, amoxicillin-clavulanate 875/125 mg twice daily for 10–14 days is appropriate. 5 Treatment should target respiratory anaerobes, viridans streptococci, S. pneumoniae, H. influenzae, and M. catarrhalis. 5
The evidence supporting antibiotic use in chronic sinusitis is notably poor, with multiple systematic reviews indicating limited quantity and quality of data. 5 Conservative therapy with antibiotics alone is successful in only one-third of chronic sinusitis cases. 5
Critical Pitfalls to Avoid
- Do not obtain routine imaging (X-ray or CT) for uncomplicated ABRS; up to 87% of viral upper respiratory infections show sinus abnormalities on imaging, leading to unnecessary interventions 1
- Ensure adequate treatment duration (≥5 days for adults, ≥10 days for children) to prevent relapse 1
- Gastrointestinal adverse effects with amoxicillin-clavulanate are common: diarrhea in 40–43% of patients; severe diarrhea in 7–8% 1
- Overuse of antibiotics in chronic sinusitis should be avoided unless there is clear evidence of bacterial infection with purulent discharge 5
- Do not delay reassessment beyond 3–5 days in non-responders; early identification prevents complications 1