Upper respiratory tract infections (URTIs) include otitis media, sinusitis, pharyngitis, laryngitis (croup), rhinitis, and epiglottitis. Most URTIs have a viral etiology and tend to resolve spontaneously; therefore, antibiotics would not be appropriate for the majority of URTIs. Nevertheless, URTIs are responsible for the majority of antibiotics prescribed in ambulatory practice and the cost is significant.1 The cost associated with otitis media has been reported between $3 to$4 billion in the United States.2 The excessive antibiotic use for URTIs has contributed to the development of bacterial resistance.3 Guidelines have been developed to reduce inappropriate antibiotic use for viral URTIs.4 This chapter will focus on acute otitis media, sinusitis, and pharyngitis because they are more frequently associated with bacterial infection and require appropriate antibiotic therapy to minimize complications.

## Otitis Media

Otitis media (OM) is an inflammation of the middle ear and represents the most common reason for prescribing antibiotics to children. Otitis media usually occurs after a viral infection of the nasopharynx and can be subclassified as acute otitis media or otitis media with effusion. Acute otitis media (AOM) is a symptomatic middle ear infection that occurs rapidly with inflammation and effusion. Otitis media with effusion (OME) is the presence of fluid in the middle ear without symptoms of acute illness. It is important to differentiate between AOM and OME because antibiotics are only useful for AOM. OM is more common in children, but can occur in all age groups. Bacteria frequently are isolated from middle ear fluid in AOM, but viruses play a predominant role. Streptococcus pneumoniae is the most common bacterial pathogen causing AOM. Other bacterial causes include Haemophilus influenzae and Moraxella catarrhalis. Viruses are isolated from middle ear fluid with or without concomitant bacteria in over half of AOM cases. Examples of AOM viruses are: respiratory syncytial virus, influenza virus, rhinovirus, and adenovirus. Lack of improvement with antibiotic therapy is often a result of viral infection with subsequent inflammation rather than antibiotic resistance.

Viral infection of the nasopharynx impairs eustachian tube function and causes mucosal inflammation, impairing mucociliary clearance and promoting bacterial proliferation and infection. Children are predisposed to AOM because their eustachian tubes are shorter and more horizontal compared to adults, which makes them less functional for drainage and protection of the middle ear from bacterial entry. Increased incidence of AOM observed with bottle-feeding, pacifier use, day care attendance, and exposure to cigarette smoke.

AOM presents as an acute onset of symptoms such as fever, otalgia, irritability, and tugging on the ear. Accompanying otoscopic examination frequently demonstrates a gray, bulging, nonmobile tympanic membrane. Since AOM often follows a viral URTI, the child may experience symptoms of runny nose, nasal congestion, and cough. Resolution of AOM symptoms usually occurs over 1 week. Pain and fever tend to resolve after 2 to 3 days, with most children becoming asymptomatic by 7 days. The diagnosis of AOM and OME ...

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