Bacterial upper respiratory tract infections (URTIs) include acute otitis media (AOM), acute bacterial rhinosinusitis, and acute pharyngitis. However, most URTIs have a viral etiology and resolve spontaneously, making antibiotics unnecessary for most URTIs. Nevertheless, most antibiotics used in ambulatory practice are prescribed for URTIs. This prescribing practice is increasingly concerning from an antimicrobial stewardship perspective given that unnecessary use and overuse of antibiotics contributes to the development of bacterial resistance. The Infectious Diseases Society of America (IDSA) and the American Academy of Pediatrics (AAP) have developed guidelines to reduce inappropriate antimicrobial use for viral URTIs. This chapter will focus on AOM, acute bacterial rhinosinusitis, and acute pharyngitis because they are more frequently associated with bacterial infections and necessitate appropriate antibiotic therapy to minimize adverse clinical and microbiological outcomes.
Otitis media (OM) is an inflammation of the middle ear and represents the most common reason for prescribing antibiotics to children; however, OM can occur across all age groups. OM occurs after a viral infection of the nasopharynx and is subclassified as AOM, otitis media with effusion (OME), or chronic otitis media. AOM is a symptomatic middle ear infection that occurs rapidly with inflammation and effusion. OME is the presence of fluid in the middle ear without symptoms of an acute illness. Chronic otitis media is persistent middle ear drainage through a perforated tympanic membrane. It is important to differentiate between AOM and OME because antibiotics are only useful for AOM.
Bacteria frequently are isolated from middle ear fluid in AOM, but viruses play a predominant role in initiating the infection. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the three most common bacterial pathogens causing AOM. Viruses are isolated from middle ear fluid with or without concomitant bacteria in over half of AOM cases. Examples of viruses isolated in AOM include respiratory syncytial virus, influenza virus, rhinovirus, and adenovirus. Lack of improvement with antibiotic therapy in AOM is often a result of viral infection with subsequent inflammation rather than antibiotic resistance.
Etiology and Pathophysiology
Viral infection of the nasopharynx impairs Eustachian tube function and causes mucosal inflammation, which impairs mucociliary clearance and promotes bacterial proliferation and infection. Children are predisposed to AOM because their Eustachian tubes are shorter and more horizontal compared to adults; this makes children's Eustachian tubes less functional for drainage and protection of the middle ear from bacterial entry. Increased incidence of AOM is observed with bottle-feeding, pacifier use, day care attendance, and exposure to cigarette smoke.
Presentation and Diagnosis
AOM presents as an acute onset of symptoms such as fever, otalgia, irritability, and ear tugging (especially in children). Accompanying otoscopic examination demonstrates a gray, bulging, nonmobile tympanic membrane. Since AOM often follows a viral URTI, the patient may also experience rhinorrhea, nasal ...