Antibiotic therapy is the mainstay of medical treatment for pediatric rhinosinusitis.] Because of increasing prevalence of beta-lactam–resistant bacteria in the community, administer antibiotics only for suspected infection as based on a careful history and physical examination. Direct the therapeutic regimen against the prevalent pathogens in the community and carefully consider suspicion for highly resistant bacteria. Typically, uncomplicated cases of acute sinusitis are responsive to amoxicillin. Most patients respond to this initial regimen. For children allergic to penicillin, a second- or third-generation cephalosporin can be used (only if the allergic reaction is not a type 1 hypersensitivity reaction). In cases of serious allergic reaction, a macrolide or clindamycin can be used.