In 2004, the Subcommittee on Management of Acute Otitis Media of the American Academy of Pediatrics and American Academy of Family Physicians published evidence-based clinical practice guidelines on the "Diagnosis and Management of Acute Otitis Media." The guidelines included a definition of acute otitis media (AOM) that included three components: 1) a history of acute onset of signs and symptoms; 2) the presence of middle-ear effusion; and 3) signs and symptoms of middle-ear inflammation. An option to observe selected children with AOM for 48 to 72 hours without initial antibiotic therapy was proposed. This option was based on age, severity of illness, and certainty of diagnosis. Despite the changing prevalence of bacterial pathogens and increasing resistance of Streptococcus pneumoniae, amoxicillin remains the first-line antibiotic for initial antibacterial treatment of AOM. The guideline also addresses the management of otalgia, choice of antibiotics after initial treatment failure, and methods for preventing AOM.