Upper respiratory tract infections (URTIs) include otitis media, sinusitis, pharyngitis, laryngitis, rhinitis, and epiglottitis. Most URTIs have a viral etiology and resolve spontaneously; therefore, antibiotics are not appropriate for the majority of URTIs. Nevertheless, URTIs are responsible for the majority of antimicrobials prescribed in ambulatory practice. This practice is concerning as the use and overuse of antimicrobials contribute to the development of microbial resistance. Guidelines have been developed to reduce inappropriate antimicrobial use for viral URTIs. This chapter will focus on acute otitis media, sinusitis, and pharyngitis because they are more frequently associated with bacterial infection and circumstantially necessitate appropriate antimicrobial therapy to minimize complications.
Otitis media (OM) is an inflammation of the middle ear and represents the most common reason for prescribing antimicrobials to children. Otitis media occurs after a viral infection of the nasopharynx and is sub-classified 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 an acute illness. It is important to differentiate between AOM and OME because antimicrobials are only useful for AOM. OM is common in children, but occurs in all age groups. Bacteria frequently are isolated from middle ear fluid in AOM, but viruses play a predominant role. 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 AOM viruses are: respiratory syncytial virus, influenza virus, rhinovirus, and adenovirus. Lack of improvement with antimicrobial therapy is often a result of viral infection with subsequent inflammation rather than antimicrobial resistance.
Viral infection of the nasopharynx impairs eustachian tube function and causes mucosal inflammation; this then impairs mucociliary clearance, which promotes bacterial proliferation and infection. Children are predisposed to AOM because their eustachian tubes are shorter and more horizontal compared to adults; this makes them 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.
AOM presents as an acute onset of symptoms such as fever, otalgia (earache), irritability, and tugging on the ear. Accompanying otoscopic examination demonstrates a gray, bulging, nonmobile tympanic membrane. Since AOM often follows a viral URTI, the child may experience symptoms of rhinorrhea, 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 day 7. The diagnosis of AOM and OME are easily confused; therefore, careful attention to history, signs, and symptoms, as well as results from pneumatic otoscopy are important. Diagnosis of AOM requires either ...