What are the hallmarks and treatment options for sinus infection?

Hallmarks of Sinus Infection

Clinical Presentation

The cardinal symptoms of acute bacterial sinusitis include nasal congestion, purulent rhinorrhea, facial/dental pain (especially over the affected sinus that worsens with movement or percussion), post-nasal drainage, headache, and cough. 1

Key Diagnostic Features in Adults

• Post-nasal purulent discharge and facial pain are the most prominent symptoms 1
• Fever occurs in less than 50% of cases 1
• Symptoms lasting less than 4 weeks define acute sinusitis 2
• Purulent nasal discharge, facial pain, and congestion are the classic triad 1

Key Diagnostic Features in Children

• Cough is most common (80% of cases) 1
• Nasal discharge occurs in 75% of cases 1
• Malodorous breath is noted in approximately 50% of preschoolers 1

Microbiology

Streptococcus pneumoniae and Haemophilus influenzae account for more than 50% of acute sinusitis cases in adults. 1

• In children, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis account for two-thirds of cases 1
• Chronic sinusitis is more commonly associated with Staphylococcus aureus and anaerobic organisms 3

Diagnostic Evaluation

• Diagnosis is primarily clinical, based on history and physical examination 2, 1
• CT scanning is the imaging technique of choice when imaging is needed, as it demonstrates abnormalities in both the ostiomeatal complex and sinus cavities 1
• Plain films and transillumination have limited value, especially in young children 4
• CT should be reserved for patients who fail maximal medical therapy, have confusing presentations, or are being considered for endoscopic surgery 4

Treatment Approach

First-Line Antibiotic Therapy

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

• For more severe infections, higher doses (875 mg twice daily) are recommended 2
• Treatment should continue until the patient is symptom-free for 7 days 2
• Complete the full course even after symptoms improve to prevent relapse 2

Alternative First-Line Options for Penicillin Allergy

For patients allergic to amoxicillin, cephalosporins (cefuroxime, cefpodoxime, cefprozil, cefdinir) are appropriate alternatives. 2

• Azithromycin should NOT be used due to significant resistance patterns 2
• Pristinamycin is an option for true beta-lactam allergy 2

Second-Line Therapy

If no improvement occurs after 3-5 days of initial therapy, switch to amoxicillin-clavulanate for better coverage against resistant bacteria. 2, 1

• Amoxicillin-clavulanate provides coverage against beta-lactamase-producing organisms 2
• For partial response, continue treatment for another 10-14 days or switch to second-line options 2

Fluoroquinolone Use

Reserve fluoroquinolones (levofloxacin 500-750 mg daily, moxifloxacin) for complicated sinusitis involving frontal, ethmoidal, or sphenoidal sinuses, or when first-line therapy fails. 2, 5

• Levofloxacin is FDA-approved for acute bacterial sinusitis using either 750 mg for 5 days or 500 mg for 10-14 days 5
• Should not be used as routine first-line therapy due to resistance concerns 2

Adjunctive Therapies

Intranasal corticosteroids should be used as an adjunct to antibiotic therapy in both acute and chronic sinusitis. 2

• Short-term oral corticosteroids (7-21 days) may be reasonable for patients with marked mucosal edema or who fail initial treatment 2, 6
• Supportive measures include adequate hydration, analgesics, warm facial packs, and sleeping with head elevated 2
• Decongestants (oral and topical) and saline irrigation promote drainage 2, 4
• Antihistamines have no role in treating sinusitis unless underlying allergic rhinitis is present 2, 4

Special Considerations and Referral Indications

Refer to a specialist when there is need to clarify allergic or immunologic basis for sinusitis, sinusitis refractory to usual antibiotic treatment, recurrent sinusitis (≥3 episodes per year), or sinusitis associated with unusual opportunistic infections. 2, 1

• Evaluate for underlying conditions including allergies, immunodeficiencies, and anatomical abnormalities in recurrent cases 2, 6
• Potential complications include intraorbital and intracranial sepsis, which may be life-threatening 1, 7

Common Pitfalls to Avoid

• Do not use azithromycin for acute bacterial sinusitis due to widespread resistance 2
• Do not discontinue antibiotics early even if symptoms improve 2
• Do not use antihistamines routinely unless allergic rhinitis is documented 4
• Do not reserve fluoroquinolones for simple maxillary sinusitis—use them only for complicated cases or treatment failures 2