Efficacy of Antibiotics in Children With Acute Sinusitis: Which Subgroups Benefit?

Inclusion Criteria: * Meets criteria for "persistent" or "worsening" presentations of sinusitis * Baseline score ≥9 on the Pediatric Rhinosinusitis Symptom Scale Exclusion Criteria: * Severe presentation (≥3 days of colored nasal discharge and fever ≥39°C * Asthma/allergic rhinitis explains symptoms * Allergy to amoxicillin-clavulanate * Immotile cilia syndrome * Cystic fibrosis * Immunodeficiency * Parental inability to read/write English or Spanish * Other concurrent infection (e.g., pneumonia, acute otitis media, streptococcal pharyngitis) * Systemic toxicity * Wheezing on exam * Antibiotic use within 15 days