What is the recommended treatment for an otherwise healthy adult with acute sinusitis?

Treatment of Acute Sinusitis in Otherwise Healthy Adults

For an otherwise healthy adult with acute sinusitis, distinguish viral from bacterial disease first: if symptoms persist beyond 10 days without improvement OR worsen after initial improvement ("double-worsening"), prescribe amoxicillin with or without clavulanate for 5-10 days; otherwise, offer watchful waiting with symptomatic relief only. 1

Distinguishing Viral from Bacterial Sinusitis

The critical first step is determining whether antibiotics are needed at all, since most acute sinusitis is viral and self-limited. 1, 2

Acute bacterial rhinosinusitis (ABRS) is likely when: 1, 2

• Symptoms persist ≥10 days without any improvement, OR
• Symptoms worsen within 10 days after initially improving ("double-worsening"), OR
• Severe symptoms present from onset (high fever ≥102°F with purulent nasal discharge for 3-4 consecutive days)

Viral rhinosinusitis is likely when: 2

• Symptoms present <10 days with gradual improvement
• No high fever or severe facial pain
• Symptoms typically peak within 3 days and resolve within 10-14 days

Initial Management Decision: Watchful Waiting vs. Antibiotics

For confirmed or presumed ABRS, you have two evidence-based options based on shared decision-making: 1

Option 1: Watchful Waiting (Preferred for Mild-Moderate Cases)

• Offer symptomatic relief measures (detailed below) 1
• Provide a "safety-net" antibiotic prescription the patient can fill if symptoms worsen or fail to improve within 7 days 1
• This approach requires assurance of follow-up 1

Option 2: Immediate Antibiotic Therapy

• Appropriate when symptoms are severe, patient preference after counseling, or follow-up cannot be assured 1

First-Line Antibiotic Therapy

When antibiotics are indicated, prescribe amoxicillin with or without clavulanate for 5-10 days. 1, 3

Specific dosing: 3, 4

• Amoxicillin 500 mg three times daily OR 875 mg twice daily
• Amoxicillin-clavulanate 875 mg/125 mg twice daily (preferred in areas with high resistance or recent antibiotic use)

For penicillin allergy: 1, 3

• Doxycycline 100 mg twice daily for 5-10 days, OR
• Respiratory fluoroquinolone (levofloxacin 500 mg daily or moxifloxacin 400 mg daily) for 5-10 days

Avoid these antibiotics due to high resistance rates: 5

• Azithromycin/macrolides (20-25% resistance)
• Trimethoprim-sulfamethoxazole (50% resistance for S. pneumoniae)

Symptomatic Relief Measures (For All Patients)

Provide symptomatic treatment regardless of whether antibiotics are prescribed: 1, 3, 2

Core symptomatic therapies: 3, 2

• Analgesics/antipyretics: Acetaminophen or ibuprofen for pain and fever
• Nasal saline irrigation: Multiple times daily for congestion relief and mucus clearance (low-risk, effective)
• Intranasal corticosteroids: Mometasone, fluticasone, or budesonide twice daily (provides modest symptom relief after 15 days; number needed to treat = 14)

Avoid decongestants and antihistamines as routine therapy, as evidence for benefit is limited and they may cause adverse effects. 6

Reassessment and Treatment Failure

Reassess the patient at 3-5 days if symptoms worsen or fail to improve: 1, 3, 4

At 7 days, if no improvement: 1, 3

• Confirm the diagnosis of ABRS
• Exclude other causes of illness and complications
• Switch to an alternative antibiotic:
  • If initially on amoxicillin → switch to amoxicillin-clavulanate
  • If initially on amoxicillin-clavulanate → switch to respiratory fluoroquinolone (levofloxacin or moxifloxacin) or doxycycline

Red Flags Requiring Immediate Evaluation

Instruct patients to seek immediate care if they develop: 3, 2

• Severe headache or high fever (≥102°F)
• Facial swelling or periorbital edema
• Visual changes or diplopia
• Altered mental status
• Severe worsening of symptoms

These may indicate complications such as orbital cellulitis, meningitis, or intracranial extension. 6

Common Pitfalls to Avoid

Do not routinely obtain imaging (CT or plain films) for uncomplicated acute sinusitis. 1, 6 Imaging is only indicated when complications are suspected or diagnosis is uncertain after clinical evaluation.

Do not prescribe antibiotics for viral rhinosinusitis (symptoms <10 days with improvement), as this contributes to antimicrobial resistance without benefit. 1, 2

Do not use antifungal therapy for acute sinusitis, as fungi are not implicated in uncomplicated acute disease. 1