What is the best treatment approach for a patient with sinusitis?

Treatment of Sinusitis

First-Line Antibiotic Treatment

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, though amoxicillin-clavulanate 875 mg/125 mg twice daily is increasingly preferred due to coverage against β-lactamase-producing organisms. 1, 2

The choice between plain amoxicillin versus amoxicillin-clavulanate depends on several factors:

• Use amoxicillin-clavulanate if the patient has recent antibiotic exposure (within past 4-6 weeks), age >65 years, moderate-to-severe symptoms, comorbid conditions, or lives in regions with high antibiotic resistance 2
• Plain amoxicillin remains acceptable for uncomplicated cases without recent antibiotic exposure 2
• Treatment duration is 10-14 days or until symptom-free for 7 consecutive days 1, 2

When to Start Antibiotics

Do not prescribe antibiotics unless symptoms meet one of three specific criteria: 2

1. Persistent symptoms ≥10 days without improvement (nasal congestion, purulent rhinorrhea, facial pain) 1, 2
2. Severe symptoms for ≥3 consecutive days (fever ≥39°C with purulent nasal discharge) 1, 2
3. "Double sickening" - worsening symptoms after initial improvement from a viral upper respiratory infection 2

Most acute rhinosinusitis (98-99.5%) is viral and resolves spontaneously within 7-10 days without antibiotics 2. Watchful waiting without immediate antibiotics is appropriate when reliable follow-up can be assured, with antibiotics started only if no improvement occurs by 7 days or symptoms worsen at any time 2.

Treatment Failure Protocol

If no improvement occurs after 3-5 days of initial antibiotic therapy, switch to a different antibiotic immediately. 1, 2

Second-Line Options:

• High-dose amoxicillin-clavulanate (2 g amoxicillin/125 mg clavulanate twice daily) for 10-14 days 2
• Respiratory fluoroquinolones - levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily for 10-14 days, providing 90-92% predicted clinical efficacy 2
• Third-generation cephalosporins - cefpodoxime, cefdinir, or cefuroxime for 10 days 1, 2

Reassess at 7 days: if symptoms persist or worsen, reconfirm the diagnosis and consider complications (orbital cellulitis, meningitis) or referral to otolaryngology 2.

Penicillin-Allergic Patients

For non-severe penicillin allergy (rash, delayed reactions), second- or third-generation cephalosporins are safe and preferred. 2

• Cefuroxime (second-generation cephalosporin) 2
• Cefpodoxime or cefdinir (third-generation cephalosporins with superior H. influenzae coverage) 2
• The risk of cross-reactivity between penicillins and second/third-generation cephalosporins is negligible for non-Type I reactions 2

For severe penicillin allergy (anaphylaxis/Type I hypersensitivity), use respiratory fluoroquinolones as first-line therapy: 2

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

Antibiotics to Avoid:

• Never use azithromycin or macrolides - resistance rates exceed 20-25% for both S. pneumoniae and H. influenzae 2, 3
• Never use trimethoprim-sulfamethoxazole - 50% resistance rate for S. pneumoniae 2
• Never use first-generation cephalosporins (cephalexin) - inadequate H. influenzae coverage 2
• Never use clindamycin as monotherapy - lacks activity against H. influenzae and M. catarrhalis 2

Essential Adjunctive Therapies

Intranasal corticosteroids should be prescribed for all patients with sinusitis, regardless of antibiotic use. 1, 2

• Mometasone, fluticasone, or budesonide twice daily 2
• Reduces mucosal inflammation, improves drainage, and enhances symptom resolution 1, 2
• Strong evidence from multiple randomized controlled trials with number needed to treat of 14 2

Additional supportive measures:

• Saline nasal irrigation - promotes mucus clearance and reduces tissue edema 2
• Analgesics (acetaminophen or NSAIDs) for pain and fever 2
• Adequate hydration 1
• Warm facial packs 1
• Sleep with head elevated 2

Short-term oral corticosteroids (typically 5 days) may be considered for patients with marked mucosal edema or who fail to respond to initial antibiotic treatment 1, 2. However, never give systemic corticosteroids without antibiotics when bacterial sinusitis is suspected, as this may suppress immune response and allow bacterial proliferation 2.

Chronic Sinusitis (Symptoms >8 Weeks)

Chronic sinusitis requires a different approach than acute bacterial sinusitis. 1

• Intranasal corticosteroids are the primary therapy 1, 4
• Daily high-volume saline irrigation 4
• Consider a course of systemic corticosteroids for chronic hyperplastic eosinophilic rhinosinusitis, which does not respond to antibiotics 1
• Antibiotics have a controversial role; longer duration therapy (3-4 weeks) may be required for chronic infectious sinusitis with possible anaerobic coverage (clindamycin or metronidazole) 1

When to Refer to a Specialist

Refer to otolaryngology or allergist-immunologist for: 1, 2

• No improvement after 7 days of appropriate second-line antibiotic therapy 2
• Recurrent sinusitis (≥3 episodes per year) 1, 2
• Suspected complications (orbital cellulitis, meningitis, abscess formation) 2
• Sinusitis refractory to two courses of appropriate antibiotics 2
• Need for evaluation of underlying allergic rhinitis, immunodeficiency, or anatomic abnormalities 1
• Presence of nasal polyps after appropriate medical therapy including oral corticosteroids 1

Critical Pitfalls to Avoid

• Do not prescribe antibiotics for symptoms <10 days unless severe symptoms are present (fever ≥39°C with purulent discharge for ≥3 consecutive days) 2
• Do not use mucus color alone to determine antibiotic need - color reflects neutrophils, not bacteria 2
• Do not continue ineffective therapy beyond 3-5 days without reassessment 2
• Do not use fluoroquinolones as routine first-line therapy in patients without documented β-lactam allergies - reserve them to prevent antimicrobial resistance 2
• Do not use decongestants, antihistamines, mucolytics, or expectorants as primary therapy - limited evidence for efficacy, though may provide symptomatic benefit in selected cases 1, 5