What is the treatment for sinusitis?

Treatment for Sinusitis

For acute bacterial sinusitis, amoxicillin 500 mg twice daily (mild disease) or 875 mg twice daily (moderate disease) for 10-14 days is the first-line treatment, but antibiotics should only be started when symptoms persist ≥10 days without improvement, severe symptoms occur for ≥3 consecutive days (fever ≥39°C with purulent discharge), or "double sickening" develops (worsening after initial improvement). 1, 2

Confirming the Diagnosis Before Treatment

Most acute rhinosinusitis (98-99.5%) is viral and resolves spontaneously within 7-10 days without antibiotics. 1, 2 The three clinical patterns that confirm bacterial sinusitis are:

• Persistent symptoms: Nasal congestion, purulent rhinorrhea, facial pain, or cough lasting ≥10 days without clinical improvement 1, 2
• Severe symptoms: Fever ≥39°C with purulent nasal discharge and facial pain for ≥3 consecutive days 1, 2
• Double sickening: Worsening symptoms after initial improvement from a viral upper respiratory infection 1, 2

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

First-Line Antibiotic Treatment

Standard Dosing for Adults

• Amoxicillin 500 mg twice daily for mild, uncomplicated disease 1, 2
• Amoxicillin 875 mg twice daily for moderate disease or areas with high prevalence of resistant S. pneumoniae 1, 2
• Treatment duration: 10-14 days or until symptom-free for 7 days 3, 2

Pediatric Dosing

• Standard dose: Amoxicillin 45 mg/kg/day in 2 divided doses for uncomplicated disease 2
• High dose: Amoxicillin 80-90 mg/kg/day in 2 divided doses for children with risk factors (age <2 years, daycare attendance, recent antibiotic use within 4-6 weeks) 2

Second-Line Treatment for Treatment Failure

If no improvement occurs after 3-5 days of initial therapy, switch to high-dose amoxicillin-clavulanate. 3, 2

Adults

• Amoxicillin-clavulanate 875 mg/125 mg twice daily for 10-14 days 2
• This provides coverage against β-lactamase-producing H. influenzae and M. catarrhalis 2

Pediatrics

• Amoxicillin-clavulanate 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 2

Alternative Second-Line Options

• Respiratory fluoroquinolones (levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily) for 10 days provide 90-92% predicted clinical efficacy 2
• Third-generation cephalosporins (cefpodoxime, cefdinir) offer superior activity against H. influenzae 3, 2

Treatment for Penicillin-Allergic Patients

Non-Severe Allergy (Rash, Mild Reactions)

Second- or third-generation cephalosporins are safe and effective: 1, 2

• Cefuroxime-axetil (second-generation) 3, 2
• Cefpodoxime-proxetil (third-generation, superior H. influenzae coverage) 3, 2
• Cefdinir (third-generation) 3, 2

The risk of cross-reactivity between penicillins and second/third-generation cephalosporins is negligible. 2

Severe Beta-Lactam Allergy (Anaphylaxis)

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

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. 1, 2

Adjunctive Therapies

Intranasal Corticosteroids (Strongly Recommended)

Intranasal corticosteroids should be used as adjunctive therapy in both acute and chronic sinusitis to reduce inflammation and improve drainage. 1, 2

• Mometasone, fluticasone, or budesonide twice daily 1
• These reduce mucosal inflammation and improve symptom resolution 1
• Safe for long-term use with minimal systemic absorption 3

Systemic Corticosteroids (Limited Use)

Short-term oral corticosteroids may be considered for: 3, 2

• Patients who fail to respond to initial antibiotic treatment 3, 2
• Marked mucosal edema 3, 2
• Acute hyperalgic sinusitis (severe pain) 2
• Typical duration: 5 days 2

Critical warning: Never give systemic corticosteroids without antibiotics when bacterial sinusitis is suspected, as this may suppress the immune response and allow bacterial proliferation. 2

Supportive Measures

• Saline nasal irrigation: High-volume daily irrigation improves mucociliary clearance and symptom scores 1, 4
• Analgesics: Acetaminophen or NSAIDs for pain and fever 1, 2
• Adequate hydration 3, 2
• Warm facial packs 3, 2
• Sleeping with head elevated 3, 2

Evidence note: Decongestants, antihistamines, mucolytics, and expectorants have limited evidence for efficacy but may provide symptomatic benefit in selected cases. 3

Chronic Sinusitis Management

Chronic sinusitis is defined as symptoms lasting >8 weeks. 3, 1

First-Line Treatment

• Intranasal corticosteroids as primary therapy 1
• Daily high-volume saline irrigation 1, 4
• Longer duration antibiotic therapy (minimum 3 weeks) for chronic infectious sinusitis 1

Consider Non-Infectious Etiology

Chronic hyperplastic eosinophilic rhinosinusitis does not respond to antibiotics and is marked by eosinophils and mixed mononuclear cells with a relative paucity of neutrophils. 3 A course of systemic corticosteroids may be necessary. 3

When to Refer to a Specialist

Referral to an otolaryngologist or allergist-immunologist is indicated for: 1, 2

• Sinusitis refractory to two courses of appropriate antibiotics 1, 2
• Recurrent sinusitis (≥3 episodes per year) 3, 1
• Suspected complications (orbital cellulitis, meningitis, intracranial involvement) 1, 2
• Need to clarify allergic or immunologic basis 3, 1
• Chronic sinusitis with nasal polyps 3
• Suspected anatomic abnormalities or immunodeficiency 3

Evaluation for Underlying Risk Factors

Patients with chronic or recurrent sinusitis should be evaluated for: 3

• Allergic rhinitis: IgE sensitization to inhalant allergens 3
• Immunodeficiency: Quantitative serum IgG, IgA, IgM levels and specific antibody responses 3
• Anatomic abnormalities: Nasal septal deviation, middle turbinate deformity, ostiomeatal complex obstruction 3

Monitoring and Follow-Up

• Reassess at 3-5 days: If no improvement, switch antibiotics or re-evaluate diagnosis 3, 2
• Reassess at 7 days: Confirm diagnosis if symptoms persist or worsen 2
• Most patients improve within 3-5 days of appropriate antibiotic therapy 2
• Complete the full antibiotic course even after symptoms improve to prevent relapse 2

Critical pitfall: Inadequate treatment duration can lead to relapse. Standard therapy is 10-14 days, though some newer antibiotics are effective in 5-7 day courses. 2