What is the recommended treatment for sinusitis?

Treatment of Sinusitis

For acute bacterial rhinosinusitis (ABRS), amoxicillin 500 mg twice daily for mild disease or 875 mg twice daily for moderate disease remains the first-line antibiotic, but symptomatic relief with analgesics, intranasal corticosteroids, and saline irrigation should be offered to all patients regardless of whether antibiotics are prescribed. 1, 2

Distinguishing Viral from Bacterial Sinusitis

Most acute rhinosinusitis (98-99.5%) is viral and resolves spontaneously within 7-10 days without antibiotics 1, 2. Antibiotics should only be initiated when one of three clinical patterns confirms bacterial infection: 1, 2

• Persistent symptoms ≥10 days without clinical improvement 1, 2
• Severe symptoms (fever ≥39°C with purulent nasal discharge) for ≥3 consecutive days 1, 2
• "Double sickening" - worsening symptoms after initial improvement from a viral upper respiratory infection 1, 2

Watchful waiting without immediate antibiotics is appropriate when follow-up can be assured, with patients instructed to start antibiotics only if no improvement occurs by 7 days or symptoms worsen at any time 1, 2.

Symptomatic Relief for All Patients (Viral and Bacterial)

First-Line Symptomatic Measures

Analgesics (acetaminophen or ibuprofen) relieve pain and fever with minimal risk 1

Saline nasal irrigation provides symptomatic relief, removes mucus that is difficult to blow out, and prevents crusting of secretions 1, 3

Intranasal corticosteroids (mometasone, fluticasone, or budesonide twice daily) reduce mucosal inflammation and improve symptom resolution, though the benefit is modest (number needed to treat = 14) 1, 2

Additional Symptomatic Options

Oral decongestants (pseudoephedrine) may provide symptomatic relief barring medical contraindications such as hypertension or anxiety 1

Topical decongestants provide palliative relief but should not exceed 3-5 days of continuous use to avoid rebound congestion and rhinitis medicamentosa 1

Antihistamines have no proven role in acute sinusitis unless the patient has concomitant allergic rhinitis 1, 4

Antibiotic Treatment for Confirmed Acute Bacterial Sinusitis

First-Line Antibiotics

Amoxicillin remains the standard first-line choice 1, 2:

• Mild disease: 500 mg twice daily for 10-14 days 1, 2
• Moderate disease or high-risk patients: 875 mg twice daily for 10-14 days 1, 2
• High-risk pediatric patients (age <2 years, daycare attendance, recent antibiotic use): 80-90 mg/kg/day in 2 divided doses 2, 5

Amoxicillin-clavulanate provides enhanced coverage against β-lactamase-producing organisms (20% of H. influenzae, 50-70% of M. catarrhalis) 1:

• Adults: 875 mg/125 mg twice daily for 5-10 days 5
• Children: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 2, 5

Penicillin-Allergic Patients

For non-severe, delayed-type reactions (rash, mild reactions), second- or third-generation cephalosporins are safe and effective 2, 5:

• Cefuroxime-axetil (second-generation) 1, 2, 5
• Cefpodoxime-proxetil or cefdinir (third-generation with superior H. influenzae activity) 1, 2, 5

For severe Type I hypersensitivity (anaphylaxis), respiratory fluoroquinolones are appropriate 2, 5:

• Levofloxacin 500 mg once daily for 10-14 days 2, 5
• Moxifloxacin 400 mg once daily for 10 days 2, 5

Critical pitfall: Azithromycin and other macrolides should NOT be used as first-line therapy due to resistance rates of 20-25% for both S. pneumoniae and H. influenzae 2, 5

Treatment Failure Protocol

Reassess at 3-5 days (adults) or 72 hours (pediatrics) 2, 5. If no improvement:

Switch to high-dose amoxicillin-clavulanate (4 g amoxicillin/250 mg clavulanate per day for adults; 90 mg/kg/day amoxicillin component for children) for 10-14 days 2, 5

If amoxicillin-clavulanate fails, switch to respiratory fluoroquinolone (levofloxacin 500-750 mg once daily or moxifloxacin 400 mg once daily) providing 90-92% predicted clinical efficacy 2, 5

Alternative for treatment failure: Ceftriaxone 1-2 g IM/IV once daily for 5 days (adults) or 50 mg/kg once daily (children) when oral medications cannot be tolerated 2, 5

Chronic Sinusitis Management (Symptoms >3 Months)

Intranasal corticosteroids are the cornerstone of treatment for chronic sinusitis due to their anti-inflammatory effects 3

Saline irrigation prevents crusting and facilitates mechanical removal of mucus 3

Longer duration antibiotic therapy (minimum 3 weeks) may be required for chronic infectious sinusitis, with attention to anaerobic pathogens (Bacteroides, Peptostreptococcus, Fusobacterium) 1, 3

Surgical intervention (functional endoscopic sinus surgery) is the mainstay when medical therapy fails, with combined medical and surgical treatment achieving >60% cure rate after 3 years 1

When to Refer to a Specialist

Refer to otolaryngology or allergy/immunology when: 3, 2

• Sinusitis refractory to two courses of appropriate antibiotics 3, 2
• Recurrent sinusitis (≥3 episodes per year) 3, 2
• Suspected complications (orbital cellulitis, meningitis, intracranial involvement) 3, 2
• Need to clarify allergic or immunologic basis 3, 2

Critical Pitfalls to Avoid

Do not prescribe antibiotics for viral rhinosinusitis lasting <10 days unless severe symptoms are present, as this contributes to antimicrobial resistance without clinical benefit 1, 2

Do not use first-generation cephalosporins (cephalexin) for sinusitis due to inadequate coverage against H. influenzae 5

Do not use clindamycin as monotherapy due to lack of activity against H. influenzae and M. catarrhalis 5

Reserve fluoroquinolones for treatment failures, severe disease, or true penicillin allergy to prevent resistance development 2, 5

Complete the full antibiotic course (10-14 days or until symptom-free for 7 days) even after symptoms improve to prevent relapse 2, 5