Treatment of Sinusitis
For acute bacterial sinusitis, initiate high-dose amoxicillin-clavulanate (1.5-4g/day in divided doses) for 10-14 days as first-line therapy to cover resistant bacteria including beta-lactamase-producing organisms. 1, 2, 3
Distinguishing Bacterial from Viral Sinusitis
Before prescribing antibiotics, confirm acute bacterial rhinosinusitis (ABRS) by one of these criteria:
- Persistent symptoms: Nasal congestion, purulent rhinorrhea, facial pain, or cough lasting ≥10 days without improvement 4
- Severe onset: High fever (>38.3°C) with purulent nasal discharge for 3-4 consecutive days 5
- Double worsening: Initial improvement followed by symptom worsening within 10 days 4
Most acute sinusitis cases are viral and resolve without antibiotics—distinguishing bacterial from viral infection prevents unnecessary antibiotic use and resistance. 4
First-Line Antibiotic Therapy
Standard Treatment
- High-dose amoxicillin-clavulanate (1.5-4g/day divided doses) for 10-14 days covers Streptococcus pneumoniae (including penicillin-resistant strains), Haemophilus influenzae, Moraxella catarrhalis, and anaerobes 6, 1, 7
- This regimen addresses both direct bacterial pathogenicity and the "shielding effect" where beta-lactamase-producing organisms protect penicillin-susceptible pathogens 7
Penicillin Allergy Alternatives
- Cefuroxime, cefpodoxime, or cefdinir for patients with non-severe penicillin allergy 6, 1, 2
- Respiratory fluoroquinolones (levofloxacin 500mg daily or moxifloxacin) for moderate disease with beta-lactam hypersensitivity 6, 2, 7
- Avoid macrolides (azithromycin, clarithromycin) as first-line due to increasing resistance, though FDA-approved azithromycin 500mg daily x3 days remains an option 8, 5
Treatment Failure Management
If no improvement within 3-5 days or worsening occurs:
- Switch to broader-spectrum therapy: Continue high-dose amoxicillin-clavulanate OR add anaerobic coverage with clindamycin or metronidazole 6, 1, 2
- Reassess diagnosis: Confirm ABRS, exclude complications (orbital cellulitis, meningitis, brain abscess), and evaluate for underlying factors 6, 4
- Consider CT imaging if not previously obtained to assess ostiomeatal complex obstruction and extent of disease 6, 2
The common pitfall here is continuing the same antibiotic beyond 21-28 days without reassessment—this indicates either resistant pathogens, structural abnormalities, or incorrect diagnosis. 6
Adjunctive Therapies
Strongly Recommended
- Intranasal corticosteroids reduce mucosal inflammation and improve sinus drainage—most important preventive intervention for recurrent cases 1, 2, 3
- High-volume saline irrigation (150mL daily) mechanically removes pathogens and improves mucociliary clearance 2, 3
- Analgesics based on pain severity assessment 4
Supportive Measures
- Adequate hydration, warm facial compresses, head elevation during sleep 1
- Oral/topical decongestants may provide symptomatic relief, but limit topical use to <3 days to avoid rebound congestion 9
Recurrent Sinusitis (≥3 Episodes/Year)
Recurrent sinusitis requires systematic evaluation of underlying causes, not just repeated antibiotic courses. 6, 2
Mandatory Evaluations
- Allergy testing for allergic rhinitis (present in significant proportion of recurrent cases) 6, 2
- CT scan of paranasal sinuses to identify anatomic abnormalities (septal deviation, ostiomeatal obstruction, nasal polyps) 6, 2, 3
- Immunologic assessment if immunodeficiency suspected: quantitative IgG/IgA/IgM, specific antibody responses to tetanus and pneumococcal vaccines 6, 2
Prevention Strategy
- Daily intranasal corticosteroids during high-risk seasons 1, 3
- Daily saline irrigation combined with intranasal steroids (more effective than either alone) 2
- Address underlying allergic rhinitis with environmental controls and immunotherapy if indicated 6
Specialist Referral Indications
- Allergist-immunologist: Suspected allergic rhinitis, immunodeficiency, or unusual pathogens 6, 2
- Otolaryngologist: Anatomic abnormalities on CT, nasal polyps persisting despite oral corticosteroids, failure of aggressive medical management after 3-4 weeks 6, 2, 3
Chronic Sinusitis (>8 Weeks Duration)
Chronic sinusitis often represents non-infectious chronic hyperplastic eosinophilic rhinosinusitis that does not respond to antibiotics. 6
- Trial of systemic corticosteroids may be necessary for eosinophil-predominant disease 6
- Coronal CT with ostiomeatal complex cuts to clarify disease extent and surgical planning 6
- Nasal-sinus biopsy if neoplasia, fungal disease, or granulomatous disease suspected 6
- Maximize medical therapy (intranasal steroids, saline irrigation, treatment of underlying rhinitis) before surgical intervention 6
Surgical Indications
Surgery (functional endoscopic sinus surgery) is indicated when: 3
- Nasal polyps obstruct drainage despite medical treatment
- Anatomic defects obstruct ostiomeatal complex
- Recurrent infectious sinusitis despite multiple appropriate antibiotic courses
- Threatened complications (orbital/intracranial extension)
The critical pitfall is premature surgical referral before adequate medical management—every effort should maximize medical therapy first. 6, 3
Special Populations
Elderly Patients
- Monitor closely for drug interactions and side effects 1, 3
- Watch for atypical presentations: fatigue, malaise, decreased appetite rather than classic facial pain 1, 3
- Lower threshold for hospitalization given higher complication risk 1, 3
Immunocompromised Patients
- Consider Pseudomonas aeruginosa and Staphylococcus aureus as potential pathogens 6, 7
- Broader-spectrum coverage may be necessary from the outset 7
Red Flags Requiring Immediate Action
Hospitalize immediately if: 1, 3
- High fever with altered mental status
- Periorbital edema or visual changes (orbital complications)
- Severe headache with meningeal signs (intracranial extension)
- Cavernous sinus thrombosis signs