What is the recommended antibiotic treatment for acute bacterial sinusitis in children?

Antibiotic Treatment for Acute Bacterial Sinusitis in Children

First-Line Antibiotic Selection

Amoxicillin with or without clavulanate is the recommended first-line antibiotic for acute bacterial sinusitis in children aged 1-18 years. 1, 2

The choice between amoxicillin alone versus amoxicillin-clavulanate depends on specific risk factors:

Standard-Dose Amoxicillin (45 mg/kg/day in 2 divided doses)

Use for children who meet ALL of the following criteria: 1, 2, 3

• Age ≥2 years
• No antibiotic exposure in the past 4-6 weeks
• Not attending daycare
• No high local prevalence of resistant S. pneumoniae

High-Dose Amoxicillin-Clavulanate (90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses)

Use for children with ANY of the following risk factors: 1, 2

• Age <2 years
• Daycare attendance
• Recent antibiotic use (within 4-6 weeks)
• Moderate to severe illness at presentation
• High local prevalence of resistant S. pneumoniae

The 2012 IDSA guideline recommends amoxicillin-clavulanate rather than amoxicillin alone as empiric therapy for all children with acute bacterial sinusitis, based on increasing prevalence of β-lactamase-producing H. influenzae in the post-pneumococcal vaccine era. 1 However, the 2013 AAP guideline allows either option, making it inclusive of the IDSA recommendation while permitting narrower-spectrum therapy when appropriate. 1

Diagnostic Criteria

Diagnose acute bacterial sinusitis when the child presents with ONE of these three patterns: 1

Persistent illness: Nasal discharge (any quality) or daytime cough (or both) lasting ≥10 days without improvement 1

Severe onset: Concurrent fever ≥39°C (102.2°F) AND purulent (thick, colored, opaque) nasal discharge for ≥3 consecutive days 1

Worsening course: Initial improvement of upper respiratory symptoms followed by new onset or worsening of nasal discharge, daytime cough, or fever after 5-7 days 1

Treatment Duration

Treat for 10-14 days total, or continue antibiotics for 7 days after the child becomes symptom-free. 1, 2 This individualized approach ensures a minimum 10-day course while avoiding prolonged therapy in asymptomatic children who are unlikely to adhere. 1

The longer 10-14 day duration is specifically recommended for children, in contrast to adults where 5-7 days may suffice. 1

Penicillin-Allergic Patients

For children with documented penicillin allergy, use second- or third-generation cephalosporins: 1

• Cefdinir (14 mg/kg/day in 1-2 divided doses)
• Cefuroxime axetil (30 mg/kg/day in 2 divided doses)
• Cefpodoxime proxetil (10 mg/kg/day in 2 divided doses)

Recent evidence demonstrates that the risk of serious allergic reactions to second- and third-generation cephalosporins in penicillin-allergic patients is negligible and no greater than in non-allergic patients. 1

Do NOT use azithromycin or other macrolides for acute bacterial sinusitis in children, even with penicillin allergy, due to significant resistance of S. pneumoniae and H. influenzae. 1, 4 Surveillance studies show 20-25% resistance rates, making these agents unsuitable. 1, 4

Alternative Parenteral Option

For children who are vomiting, unable to tolerate oral medication, or unlikely to be adherent, give ceftriaxone 50 mg/kg IM or IV as a single dose. 1, 2 After clinical improvement at 24 hours, switch to oral therapy to complete the course. 1 Children still significantly febrile or symptomatic at 24 hours may require additional parenteral doses before oral transition. 1

Treatment Failure Protocol

Reassess at 72 hours. If the child shows worsening symptoms or failure to improve, switch to high-dose amoxicillin-clavulanate (if not already prescribed) or consider ceftriaxone. 1, 2

The 72-hour threshold is evidence-based: in randomized trials, 79% of antibiotic-treated children who would ultimately respond had already done so by day 3, while only 9% of placebo-treated children who failed at day 3 showed improvement between days 3-10 without intervention. 2

Watchful Waiting Option for Persistent Illness

For children with persistent illness (not severe or worsening), either antibiotic therapy OR an additional 3 days of observation is acceptable initial management. 1, 2 This represents an opportunity for shared decision-making with families, balancing the benefits of antibiotics (number needed to treat: 3-5) against adverse effects (number needed to harm: 3, primarily diarrhea). 1

However, antibiotic therapy is mandatory for: 1

• Severe onset or worsening course presentations
• Coexisting acute otitis media, pneumonia, or streptococcal pharyngitis
• Suspected orbital or intracranial complications

Red Flags Requiring Immediate Specialist Consultation

Suspect complications and obtain urgent imaging (contrast-enhanced CT or MRI) plus ENT/neurosurgery consultation for: 1, 2

• Periorbital or orbital swelling, especially with proptosis
• Impaired extraocular muscle function or visual acuity
• Severe headache with photophobia
• Altered mental status or seizures
• Focal neurologic findings

Initiate IV vancomycin plus ceftriaxone or cefotaxime immediately for suspected orbital or intracranial complications. 2

Critical Pitfalls to Avoid

Do not obtain plain radiographs, CT, or MRI to differentiate bacterial sinusitis from viral upper respiratory infection in uncomplicated cases. 1 Imaging is reserved only for suspected complications. 1

Do not use trimethoprim-sulfamethoxazole for acute bacterial sinusitis, even in penicillin-allergic patients, due to high resistance rates. 1

Ensure adequate treatment duration—premature discontinuation leads to relapse. 1, 4 The minimum effective course is 10 days for children. 1, 2

Recent High-Quality Evidence

A 2023 JAMA cohort study of 198,942 propensity-matched children found no difference in treatment failure between amoxicillin-clavulanate and amoxicillin alone (RR 0.98,95% CI 0.92-1.05), but amoxicillin-clavulanate was associated with higher rates of gastrointestinal symptoms (RR 1.15) and yeast infections (RR 1.33). 5 This supports the AAP's position that amoxicillin alone remains appropriate for low-risk children, while amoxicillin-clavulanate should be reserved for those with risk factors. 1, 2