Sinusitis Workup and Management
Classification and Diagnosis
Classify sinusitis by duration to guide management: acute (<4 weeks), subacute (4-8 weeks), chronic (≥8 weeks), or recurrent (≥3 episodes/year). 1
Clinical Presentation
- Acute sinusitis presents with persistent upper respiratory symptoms, purulent rhinorrhea, postnasal drainage, anosmia, nasal congestion, facial pain, headache, fever, cough, and purulent discharge lasting less than 4 weeks 1
- Chronic sinusitis requires symptoms persisting ≥8 weeks with abnormal CT or MRI findings; some patients present with vague or insidious symptoms 1
- Distinguish bacterial sinusitis from viral upper respiratory infection: bacterial becomes more likely after 7-10 days of persistent symptoms 2, 3
Diagnostic Workup
- Clinical diagnosis is based on history and physical examination for uncomplicated acute sinusitis; imaging is not required 4, 3
- CT imaging is indicated for chronic sinusitis evaluation, treatment failures, or suspected complications 1, 5
- Order coronal sinus CT with extra cuts through the ostiomeatal complex to clarify disease extent and location 1
- Consider nasal-sinus biopsy in suspected neoplasia, fungal disease, granulomatous disease, or tracheal biopsy for ciliary evaluation 1
Initial Management of Acute Sinusitis
First-Line Antibiotic Therapy
Start with amoxicillin, trimethoprim-sulfamethoxazole, or amoxicillin-clavulanate for 10-14 days as first-line therapy. 4
- Amoxicillin-clavulanate is FDA-approved for sinusitis caused by beta-lactamase-producing H. influenzae and M. catarrhalis 6
- Continue treatment until 7 days after symptom resolution or for 10-14 days total 7
Adjunctive Therapies
- Nasal corticosteroids reduce mucosal inflammation and are beneficial in both acute and chronic sinusitis 5, 8
- Decongestants (topical or systemic) may reduce tissue edema and facilitate drainage, though prospective evidence is limited 7, 4
- Supportive measures: adequate hydration, analgesics, warm facial applications, steam inhalation, saline irrigation, and head elevation while sleeping 7, 5
Important Caveats
- Avoid antihistamines in acute bacterial sinusitis unless allergic rhinitis is present (lack of evidence for benefit) 7
- Reassess if no improvement within 3-5 days of antibiotic treatment 1, 7
Management of Treatment Failures
Partial Response (Improved but Not Resolved)
- Continue antibiotic treatment for another 10-14 days 1
- Alternatively, switch to antibiotics covering resistant bacteria 1
Poor Response (No Improvement After Initial Treatment)
Switch to high-dose amoxicillin-clavulanate (90 mg/kg amoxicillin and 6.4 mg/kg clavulanate, maximum 2g every 12 hours) for 10-14 days. 7, 5
Alternative antibiotics for resistant bacteria or penicillin allergy:
- Cephalosporins: cefuroxime, cefpodoxime, cefprozil, or cefdinir 1, 7
- Respiratory fluoroquinolones (adults only): levofloxacin or moxifloxacin for 5-7 days with excellent coverage for resistant strains 8
- Macrolides (clarithromycin, azithromycin) only in severe penicillin allergy, but avoid as second-line due to weak activity against resistant organisms 7, 8
Failure After 21-28 Days
- Consider pathogens not covered by prior antibiotics, nasal polyps, or noncompliance 1, 5
- Add anaerobic coverage with clindamycin or metronidazole to broader-spectrum agents 1, 5
- Order sinus CT scan if not already done 1, 5
- Evaluate underlying risk factors in detail 1
Chronic Sinusitis Management
Recognize that chronic sinusitis (≥8 weeks) may be noninfectious and requires a different approach than acute bacterial sinusitis. 1
Medical Management
- Chronic hyperplastic eosinophilic rhinosinusitis does not respond to antibiotics; consider systemic corticosteroids 1
- Maximize medical treatment for underlying rhinitis before surgical intervention 1
- Continue nasal corticosteroids and saline irrigation long-term 5, 9
Surgical Considerations
Refer to otolaryngology for:
- Significant nasal septal deviation compressing the middle turbinate into the ostiomeatal complex 1
- Obstructing nasal polyps after appropriate medical therapy including oral corticosteroids 1
- Recurrent or chronic symptoms with radiographic ostiomeatal obstruction despite aggressive medical management 1
- Functional endoscopic sinus surgery is the contemporary surgical approach 1
- Most patients require continued individualized medical therapy post-surgery 1
Evaluation of Underlying Risk Factors
Allergic Rhinitis
- Evaluate for IgE sensitization to inhalant allergens in suspected allergic rhinitis 1
- Treat with environmental control, pharmacotherapy, and allergen immunotherapy in selected patients 1
- Differentiate from vasomotor rhinitis, NARES, and rhinitis medicamentosa 1
Immunodeficiency Evaluation
Refer to allergist-immunologist for chronic or recurrent sinusitis associated with:
- Otitis media, bronchitis, bronchiectasis, or pneumonia 1
- Prior surgical procedures with continued sinusitis 1
- Evaluation includes quantitative serum IgG, IgA, IgM levels and specific antibody responses to tetanus toxoid or pneumococcal polysaccharide vaccine 1
Anatomic Abnormalities
Specialist Referral Indications
Consult allergist-immunologist for:
- Recurrent sinusitis (≥3 episodes/year) requiring evaluation of inflammation, allergy, immunodeficiency, and anatomic abnormalities 1, 7
- Treatment of underlying allergic factors and evaluation of unusual pathogens 1, 5
- Chronic sinusitis with systemic manifestations 1
Consult otolaryngology for: