What is the recommended treatment for a sinus infection?

Treatment of Sinus Infection

Initial Assessment: Determining Need for Antibiotics

Most sinus infections are viral and do not require antibiotics—only 0.5% to 2.0% of acute rhinosinusitis cases are bacterial, yet antibiotics are prescribed in 81-92% of cases. 1

When to Prescribe Antibiotics

Antibiotics are indicated only in these specific scenarios:

• Severe symptoms at presentation: High fever (≥39°C/102°F), purulent nasal discharge, and maxillary pain/swelling for 3-4 consecutive days 1, 2
• Persistent symptoms: Nasal symptoms or cough lasting >10 days without improvement 1, 2
• Worsening symptoms: Initial improvement followed by clinical deterioration ("double-sickening") 1, 2

For mild symptoms lasting <7 days, watchful waiting with symptomatic treatment is appropriate—antibiotics should be withheld. 1, 3

First-Line Antibiotic Treatment

Standard Therapy for Maxillary Sinusitis

Amoxicillin 500 mg twice daily for 10-14 days is the first-line antibiotic choice for most adults with acute bacterial sinusitis. 2

• For severe infections, increase to amoxicillin 875 mg twice daily 2
• Continue treatment until symptom-free for 7 days (typically 10-14 days total) 2
• Complete the full course even after symptoms improve to prevent relapse 2

Penicillin-Allergic Patients

For true penicillin allergy, use these alternatives:

• Cephalosporins: Cefuroxime, cefpodoxime, cefprozil, or cefdinir 2
• Avoid azithromycin and other macrolides due to significant resistance patterns in Streptococcus pneumoniae and Haemophilus influenzae 2

Second-Line Treatment

When to Switch Antibiotics

If no improvement occurs after 3-5 days of initial therapy, switch to a different antibiotic. 2

• Amoxicillin-clavulanate provides better coverage against resistant bacteria and is the preferred second-line agent 2
• For frontal, ethmoidal, or sphenoidal sinusitis (more complicated locations), consider fluoroquinolones: levofloxacin 500 mg daily for 10-14 days or 750 mg daily for 5 days 2, 4

Fluoroquinolone Considerations

• Reserve levofloxacin or moxifloxacin for treatment failure or complicated sinusitis involving non-maxillary sinuses 2
• Levofloxacin is FDA-approved for acute bacterial sinusitis at 750 mg daily for 5 days or 500 mg daily for 10-14 days 4
• Do not use fluoroquinolones as routine first-line therapy due to resistance concerns and adverse effect profile 2

Adjunctive Therapies

Intranasal Corticosteroids (Strongly Recommended)

Intranasal corticosteroids should be used as adjunctive therapy in both acute and chronic sinusitis—this recommendation is supported by multiple randomized controlled trials. 1, 2

• Start intranasal corticosteroids for moderate cases after 5 days if symptoms persist 1
• Continue even when antibiotics are prescribed 2
• Note: Intranasal corticosteroids are not FDA-approved specifically for acute bacterial sinusitis, but evidence supports their use 1

Oral Corticosteroids (Limited Use)

• Short-term oral corticosteroids (e.g., dexamethasone 4 mg) may be used for acute hyperalgic sinusitis (severe pain) as adjunctive therapy only 2
• Consider for patients with marked mucosal edema who fail initial treatment 2
• Never use systemic corticosteroids as monotherapy—antibiotics remain necessary for bacterial infection 2

Supportive Measures

• Nasal saline irrigation is recommended for symptom relief and promoting drainage 1
• Adequate hydration, analgesics for pain, warm facial packs, and sleeping with head elevated 2
• Oral and topical decongestants may provide symptomatic relief, though data on efficacy are limited 1

Antihistamines

• Do not routinely use antihistamines for acute bacterial sinusitis 1
• Consider only in patients with concurrent allergic rhinitis during allergy season 1, 5

Pediatric Dosing

• Amoxicillin 45 mg/kg/day in 2 divided doses for standard therapy 2
• High-dose amoxicillin 80-90 mg/kg/day in 2 divided doses for areas with high prevalence of resistant S. pneumoniae 2
• Amoxicillin-clavulanate 80-90 mg/kg/day (amoxicillin component) for children <2 years, in daycare, or with recent antibiotic use 2

Common Pitfalls to Avoid

• Do not prescribe antibiotics based on colored nasal discharge alone—mucus color reflects neutrophils, not bacteria 1
• Do not treat viral rhinosinusitis with antibiotics—wait at least 7-10 days to distinguish bacterial from viral infection 1, 3
• Approximately 60% of presumed bacterial sinusitis cases resolve spontaneously without antibiotics 1
• Unnecessary antibiotic use increases resistance, adverse events, and healthcare costs 1

When to Refer to a Specialist

Refer to an otolaryngologist or allergist when:

• Sinusitis is refractory to usual antibiotic treatment 2
• Recurrent sinusitis (≥3 episodes per year) occurs 2
• Need to clarify allergic or immunologic basis for sinusitis 2
• Unusual opportunistic infections are present 2
• Underlying anatomic abnormalities, immunodeficiency, or chronic inflammatory conditions are suspected 2, 6