What are the symptoms and treatment options for bacterial rhinosinusitis?

Symptoms of Bacterial Rhinosinusitis

Bacterial rhinosinusitis requires one of three specific clinical patterns: persistent symptoms ≥10 days without improvement, worsening after 5-7 days of initial improvement ("double-sickening"), or severe onset with high fever (≥39°C) plus purulent nasal discharge for 3-4 consecutive days. 1

Cardinal Symptoms Required for Diagnosis

Purulent nasal discharge is essential—without it, bacterial rhinosinusitis is unlikely even when other symptoms are present. 1, 2 The diagnosis becomes highly specific when purulent discharge occurs with:

• Nasal congestion or obstruction 1
• Facial pain or pressure (especially unilateral and localized to a specific sinus region) 1

These three symptoms—purulent discharge, nasal obstruction, and facial pain—form the diagnostic cornerstone. 1

Three Diagnostic Patterns (Any One Qualifies)

Pattern 1: Persistent Illness

• Symptoms lasting ≥10 days without any clinical improvement 1
• This is the most common presentation 3
• Approximately 60% of patients with symptoms beyond 10 days have bacterial infection on sinus aspiration 1, 2

Pattern 2: Worsening Course ("Double-Sickening")

• Initial improvement followed by new onset or worsening of symptoms after 5-7 days 1
• New fever, headache, or increased nasal discharge after initial improvement 1, 2
• This pattern allows the earliest diagnosis at 5-7 days 3

Pattern 3: Severe Onset

• High fever ≥39°C (102°F) AND purulent nasal discharge for at least 3-4 consecutive days at illness onset 1, 4
• Can be recognized within the first 3-4 days of illness 3

Additional Supporting Symptoms

When present alongside the cardinal symptoms and one of the three patterns above:

• Postnasal drainage 1, 3
• Hyposmia or anosmia (reduced or absent sense of smell) 1
• Maxillary dental pain 1
• Ear pressure or fullness 1
• Headache 3
• Cough (may persist but is nonspecific) 1
• Fatigue 1

Critical Pitfalls to Avoid

Colored Discharge Alone Is Not Diagnostic

Mucopurulent nasal discharge occurs normally after a few days of viral infection and does not distinguish bacterial from viral rhinosinusitis. 1, 3 The color change reflects white blood cells and desquamated epithelium, not necessarily bacteria. 5

Duration <10 Days Without Worsening

Symptoms present for fewer than 10 days without a worsening pattern are unlikely to represent bacterial infection. 2 Most viral URIs last 5-7 days, but cough and nasal drainage can persist 10+ days in 40% of uncomplicated viral infections. 1, 2, 5

Fever Pattern Matters

Fever in viral URIs typically resolves within 24-48 hours. 3 Persistent high fever (≥39°C) with purulent discharge for 3-4 consecutive days suggests bacterial infection. 1

Physical Examination Has Limited Value

Physical examination provides limited diagnostic information for bacterial rhinosinusitis. 1, 2 Signs like sinus tenderness, mucosal erythema, and visible purulent secretions may be present but are not specific. 3

Imaging Is Not Routinely Indicated

Plain radiographs are neither useful nor cost-effective. 1 CT scans show abnormalities in 87% of viral URIs, with 79% showing marked improvement after 2 weeks without antibiotics. 1, 2 Imaging should be reserved for suspected complications, immunocompromised patients, or recurrent disease. 1

Distinguishing Bacterial from Viral Rhinosinusitis

Viral URI Characteristics

• Symptoms peak at days 3-6 and improve by day 7-10 1, 2
• Fever resolves within 24-48 hours 3
• Sneezing and sore throat predominate early 1
• Clear, watery discharge initially 5
• Steady improvement without biphasic pattern 2

Bacterial Superinfection Indicators

• Symptoms persist beyond 10 days OR worsen after 5-7 days 1, 6
• Unilateral facial pain/pressure increases specificity 1, 2
• High fever (≥39°C) with purulent discharge for 3-4 days 1, 4

Treatment Implications Based on Symptoms

When Antibiotics Should Be Considered

Antibiotics are indicated for patients with ≥3 days of severe symptoms, significant worsening after 3-5 days, or ≥7 days of persistent symptoms. 4 The IDSA guideline specifies treatment for any of the three diagnostic patterns above. 1

First-Line Antibiotic Selection

For patients without recent antibiotic exposure (past 4-6 weeks) and mild disease, amoxicillin is first-line therapy for 10-14 days. 1, 4, 7 For moderate disease or recent antibiotic use, amoxicillin-clavulanate (4g amoxicillin/250mg clavulanate daily) or respiratory fluoroquinolones (levofloxacin, moxifloxacin) provide 90-92% predicted clinical efficacy. 1, 6

Beta-Lactam Allergy Alternatives

For beta-lactam allergic patients, doxycycline or respiratory fluoroquinolones are appropriate. 1, 4, 7 Levofloxacin 500mg daily for 5-10 days or 750mg daily for 5 days is FDA-approved for acute bacterial sinusitis. 8

Expected Response to Treatment

Improvement should occur within 3-5 days of appropriate antibiotic therapy. 1 Worsening or no improvement after 3-5 days warrants broadening coverage or switching antimicrobial class. 1