What is the recommended treatment for acute and chronic sinusitis?

Treatment of Acute and Chronic Sinusitis

Acute Bacterial Sinusitis

For acute bacterial sinusitis, withhold antibiotics unless symptoms persist ≥10 days without improvement, severe symptoms are present (fever ≥39°C plus purulent discharge plus facial pain for ≥3-4 days), or "double sickening" occurs (worsening after initial improvement); when antibiotics are indicated, prescribe amoxicillin-clavulanate 875/125 mg twice daily for 5-10 days as first-line therapy. 1, 2, 3

Diagnostic Criteria Before Starting Antibiotics

Antibiotics are warranted only when one of these three criteria is met:

• Persistent symptoms ≥10 days with purulent nasal discharge plus either nasal obstruction or facial pain/pressure 1, 2
• Severe symptoms ≥3-4 consecutive days with fever ≥39°C, purulent discharge, and facial pain 1
• "Double sickening" pattern: initial improvement from viral URI followed by worsening within 10 days 1

Critical caveat: 98-99.5% of acute rhinosinusitis is viral and resolves spontaneously within 7-10 days; purulent nasal discharge alone does not confirm bacterial infection—it simply reflects neutrophilic inflammation common to viral disease. 1, 2

First-Line Antibiotic Regimen

• Standard dose: Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days achieves 90-92% predicted clinical efficacy against S. pneumoniae, H. influenzae, and M. catarrhalis 1, 3
• High-dose regimen: Amoxicillin-clavulanate 2 g/125 mg twice daily for patients >65 years, recent antibiotic use, moderate-to-severe symptoms, or comorbidities (diabetes, chronic organ disease) 1
• Treatment duration: 10-14 days traditionally, though recent data support 5-7 day courses in uncomplicated cases with comparable efficacy and fewer adverse events 1, 3

Penicillin Allergy Alternatives

Non-severe (non-type I) allergy:

• Second- or third-generation cephalosporins (cefuroxime, cefpodoxime, cefdinir, cefprozil) for 10 days; cross-reactivity with penicillins is <1% 1

Severe (type I/anaphylactic) allergy:

• Preferred: Levofloxacin 500 mg once daily for 10-14 days or moxifloxacin 400 mg once daily for 10 days, providing 90-92% predicted efficacy against multidrug-resistant organisms 1
• Less optimal: Doxycycline 100 mg once daily for 10 days (77-81% predicted efficacy, 20-25% bacteriologic failure); use only when fluoroquinolones are contraindicated 1, 2

Avoid these antibiotics:

• Azithromycin/macrolides: 20-25% resistance rates in S. pneumoniae and H. influenzae 1
• Trimethoprim-sulfamethoxazole: 50% resistance in S. pneumoniae, 27% in H. influenzae 1
• First-generation cephalosporins: ~50% of H. influenzae strains produce β-lactamase 1

Adjunctive Therapies for Acute Sinusitis

All patients should receive:

• Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily markedly reduce mucosal inflammation and speed symptom resolution (number needed to treat = 14) 1, 2, 3
• Saline nasal irrigation 2-3 times daily promotes mucus clearance and provides symptomatic relief 1, 2, 3
• Analgesics (acetaminophen or ibuprofen) for pain and fever; use NSAIDs cautiously in elderly with renal impairment, cardiovascular disease, or anticoagulation 1, 2, 3
• Decongestants may be employed, limiting topical use to ≤3 days to avoid rebound congestion; oral agents require caution in patients with hypertension or cardiac disease 1, 2

Avoid antihistamines unless concurrent allergic rhinitis is present, as they may thicken secretions 2, 3

Monitoring and Treatment Failure

• Reassess at 3-5 days: Lack of clinical improvement (persistent purulent drainage, unchanged facial pain, or worsening) warrants immediate escalation to high-dose amoxicillin-clavulanate or a respiratory fluoroquinolone 1, 2, 3
• Expected timeline: Noticeable improvement within 3-5 days, complete resolution by 10-14 days or when symptom-free for 7 consecutive days; only 30-41% of patients improve by days 3-5, and zero improvement at this point indicates treatment failure 1
• Second-line therapy: Switch to levofloxacin 500 mg once daily for 10-14 days or moxifloxacin 400 mg once daily for 10 days if no improvement after 3-5 days of first-line therapy 1, 3

Red Flags Requiring Urgent ENT Referral

• No improvement after 7 days of appropriate second-line antibiotic therapy 1, 2
• Worsening symptoms at any time (increasing facial pain, fever, purulent drainage) 1, 2
• Signs of complications: severe headache, visual changes, periorbital swelling/erythema, proptosis, diplopia, altered mental status, or cranial nerve deficits 1, 2
• Recurrent sinusitis (≥3 episodes per year) 1, 2

Special Considerations for Elderly Patients

• Renal dose adjustments: For CrCl 10-30 mL/min, reduce amoxicillin-clavulanate to 875/125 mg once daily; for CrCl <10 mL/min, give 875/125 mg every 24 hours 1
• Hemodialysis: Administer 875/125 mg immediately after each dialysis session (typically three times per week) 1
• GI adverse effects: Diarrhea occurs in 40-43% of patients, severe diarrhea in 7-8%; elderly patients have higher risk for C. difficile infection 1
• Polypharmacy: Review for drug-drug interactions with fluoroquinolones (warfarin, antiarrhythmics, antidiabetic agents) 1

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Chronic Rhinosinusitis (CRS)

For chronic rhinosinusitis (symptoms ≥12 weeks), prescribe intranasal corticosteroids twice daily plus saline nasal irrigation 2-3 times daily as first-line therapy; reserve antibiotics only for evidence of superimposed acute bacterial infection, and refer to ENT if first-line medical therapy fails. 4, 5, 6

Diagnostic Criteria

CRS is defined by at least two of these four cardinal symptoms for ≥12 consecutive weeks, plus objective evidence on examination or imaging:

• Facial pain/pressure 5
• Hyposmia/anosmia 5
• Nasal drainage 5
• Nasal obstruction 5

Objective evidence may be obtained via anterior rhinoscopy, nasal endoscopy, or sinus CT (preferred imaging modality). 5

First-Line Medical Therapy

• Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily reduce inflammation, decrease nasal polyp size, and improve nasal blockage, rhinorrhea, and loss of smell 4, 5, 7, 6
• Saline nasal irrigation 2-3 times daily enhances mucociliary clearance, improves sinus drainage, and provides symptomatic relief 4, 5, 8, 6

Proper technique for intranasal corticosteroids:

1. Shake the bottle well
2. Look down by bending your neck toward the floor
3. Use your right hand for the left nostril and left hand for the right nostril
4. Aim toward the outer wall (not the nasal septum) to prevent irritation and bleeding
5. Do not sniff hard 4

Role of Antibiotics in CRS

Antibiotics should be reserved for patients with evidence of an active, superimposed acute bacterial infection (purulent drainage, fever, worsening symptoms). 5, 6 There is no role for routine antibiotic use in uncomplicated CRS.

Adjunctive Therapies

• Short courses of oral corticosteroids may be considered for severe CRS with nasal polyps or when rapid symptomatic improvement is needed 7, 6
• Intranasal corticosteroid drops may be used when intranasal spray fails to demonstrate efficacy 7

Assessment for Nasal Polyps

Identifying nasal polyps is critical because they affect diagnostic testing and treatment management:

• Large polyps obstructing the nasal cavity are easily visualized with a nasal speculum or handheld otoscope 4
• Small polyps in the middle meatus or posterior nasal cavity may only be detected by nasal endoscopy 4
• CT imaging is useful for unilateral polyps, concern for polyps extending outside the nasal cavity, or atypical presentations 4

About 4% of patients with CRS have concurrent nasal polyps; an association exists between asthma, nasal polyps, and aspirin sensitivity. 4

When to Refer to ENT

• Failure to respond to first-line medical therapy (intranasal corticosteroids plus saline irrigation) 5, 6
• Recurrent sinusitis (≥3 episodes per year) 5
• Suspected anatomical abnormalities, immunodeficiency, vasculitides, granulomatous diseases, or cystic fibrosis 5, 6
• Consideration for endoscopic sinus surgery when medical management fails 5, 7, 6

Postoperative care: Intranasal corticosteroids should be continued after endoscopic sinus surgery. 7

Common Pitfalls to Avoid

• Routine imaging for uncomplicated acute rhinosinusitis is unnecessary: Up to 87% of viral URIs show sinus abnormalities on imaging, leading to unwarranted interventions 1
• Do not prescribe antibiotics based solely on purulent nasal discharge or symptom duration <10 days unless severe features are present 1, 2
• Prolonged use of topical decongestants (>3 days) leads to rebound congestion 4, 2
• Overdiagnosis of bacterial sinusitis leads to unnecessary antibiotic use and resistance 2
• Failure to recognize complications such as orbital cellulitis or intracranial extension requiring urgent intervention 2