Otitis media (OM) is a global health care problem most commonly seen in the pediatric population. Aside from upper respiratory infections, OM is the most commonly rendered diagnosis in the pediatric primary care setting. The majority of children will be diagnosed with at least one episode of acute otitis media (AOM) with rates of incidence peaking at age 2. Various retrospective studies demonstrate a wide berth of incidence, suggesting that 19–62% of children will experience at least one episode of AOM by age 1, and 50–84% of children by age 3.

While mainly considered a pediatric medical problem, OM does present in the adolescent and adult population, albeit at a lower rate. Approximately 3% to 15% of all-comers with OM presenting to otolaryngologists are adults.

Over the past decade, in particular, health care discussions have intently focused on cost and consequences of medical conditions and interventions. While the economic implications of OM are largely abstruse, estimates of a single episode of AOM range from $233 to $1330 USD. When considering these figures, OM (including medical and surgical interventions) in the United States costs $3 to 18 billion dollars annually.

Essentials of Diagnosis

• OM is stratified into two distinct categories: AOM and otitis media with effusion (OME).
  
• The most common bacterial pathogens that cause AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Branhamella (moraxella) catarrhalis.
  
• OME is defined as the presence of a middle ear effusion for 3 months or more.

Classification of a disease process is paramount to optimal diagnosis and management. Historically, extensive efforts have been put forth to define OM and its manifestations. Generally, OM refers to an inflammatory process localized to the middle ear cleft. The term “otitis media” can be separated into two distinct categories: AOM and OME.

AOM is characterized by a rapid onset of signs and symptoms, such as pyrexia and otalgia, leading to inflammation of the middle ear. Traditionally, terms such as acute suppurative or purulent OM have been used interchangeably with AOM. Current recommendations state, however, that AOM is the most accurate term used to describe middle ear inflammation in absence of effusion. Recurrent AOM is defined as: three or more episodes in a 6 month period, or four or more episodes in a 12 month period with complete resolution of symptoms between episodes.

OME, as the name suggests, is characterized by an inflammation of the middle ear space with the presence of effusion. As in the case with AOM, myriad terms such as secretory, nonsuppurative, and serous OM have been used synonymously with OME. Because effusions localized to the middle ear space may be asymptomatic or sterile and/or contain bacteria or even purulence, it is a misnomer to describe all effusions as “secretory” or “serous” or “transudative.”

The middle ear cleft is a continuous space that begins at the Eustachian tube orifice in the nasopharynx and extends to include the mastoid air cells. The cleft comprises three different contiguous components: the Eustachian tube, the middle ear, and the mastoid air cells (including the petrosa). The middle ear cleft is lined with variable epithelium—ranging from thick, ciliated respiratory epithelium found in the Eustachian tube to the thin, nonglandular cuboidal epithelium in the mastoid cells.

The underlying pathogenesis of all forms of OM (with the exception of cholesteatoma-related OM) is Eustachian tube dysfunction. The main function of the Eustachian tube is to aerate the middle ear space, providing pressure equivalent to atmospheric pressure. Additionally, the Eustachian tube plays a role in mucociliary clearance of the middle ear space and furthermore, prevents nasopharyngeal contents from entering the middle ear. Obstruction of the Eustachian tube, whether it is functional (eg, failure of contraction of tensor veli palatini during swallowing) or anatomic (eg, adenoid hypertrophy), results in the development of OM. Also of note, in patients with OM, there is an increase in the number of goblet cells found in the respiratory epithelium lining the Eustachian tube. While most episodes of AOM are preceded by viral infections, the majority of AOM have a bacterial component. Table 49–1 provides a comparative evaluation of middle ear cultures from children worldwide.

Despite the environmental differences, the results are universal—the most common bacterial pathogens found in AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

OME has a similar pathogenesis to AOM in that Eustachian tube dysfunction is nearly universal in children with OME as well. OME develops following untreated or unresolved episodes of AOM. Teele et al. found persistent effusion (>30 days) in 40% of children after their first episode of AOM, and continued effusion (up to 3 months) in 10%. Risk factors for AOM and subsequent OME include parental smoking, absence of breast feeding, day care attendance, craniofacial anomalies, adenoid hypertrophy, and allergic rhinitis. All predisposing factors appear to have a deleterious impact on Eustachian tube function.

Essentials of Diagnosis

• Manifestations of AOM include: otalgia, pyrexia, thickened or bulging tympanic membrane, hearing loss, and otorrhea.
  
• Manifestations of OME include: persistent hearing loss, dull or immobile tympanic membrane, and flat tympanogram.

Accurate diagnosis of AOM versus OME is becoming increasingly important, especially in the present day challenge of antibiotic-resistant organisms. Diagnosis of AOM and OME can be made by direct visualization of the TM using an otoscope or pneumatic otoscope. The symptoms most often associated with AOM are otalgia, fevers, decreased appetite, upper respiratory infection, and fatigue. In children less than 2 years old, otalgia is evidenced by fussiness, insomnia, and generalized irritability. Since these symptoms are vague and may be attributable to a variety of conditions, symptomatology alone should not be used as sole criteria to render a diagnosis of AOM or OME.

Examination of the TM can be challenging and heavily clinician dependent. Description of otoscopic findings is variable and subjective. It is helpful to consider physical examination of the TM systematically—the use of a mnemonic, “COMPLETES” has been published as a teaching and clinical tool to ensure thorough and methodical examination (Table 49–2).

Otoscopy in AOM classically demonstrates a thickened, hyperemic, immobile TM. As diagnosis can often be made on history and physical exam alone, further studies are not indicated for AOM. OME, in contrast, is often asymptomatic. The most common complaint associated with OME is decreased hearing. Otoscopy classically demonstrates a dull gray- or yellow-tinged, immobile TM. If the TM is clear, bubbles or air fluid levels can be elucidated. Tympanometry and audiometry are complimentary diagnostic tools used in evaluating patients with OME.