Chapter 86

Otitis Media

Margaret Thorman Hartig

Definition and Epidemiology

Otitis media, characterized by fluid in the middle ear, is a group of inflammatory or infective processes that may be bacterial, fungal, or viral in origin and is most often associated with upper respiratory tract infections or allergies. Otitis media is the most frequent childhood infectious illness, with the peak incidence at 6 to 15 months of age.¹ It accounts for a significant number of all antimicrobial prescriptions in primary care.¹^,² Severity and presentation vary. Symptoms and findings often are part of a continuum, despite the common practice of identifying discrete diagnoses. This continuum and its subtypes complicate diagnosis, as one condition often evolves into another.

Acute otitis media (AOM), with bacterial or viral infection of the middle ear fluid, has a rapid onset and short duration. Otitis media with effusion (OME) describes accumulation of serous fluid in the middle ear without acute inflammation. OME can precede or follow AOM, but barotrauma or allergy also can precipitate an occurrence. Middle ear effusion (MEE) signifies an accumulation of serous fluid in the middle ear and can be associated with AOM, often persisting for weeks or months after an episode of AOM.

Chronic effusion (known also as serous otitis media or glue ear) may persist for several months, with or without signs of infection.² Children aged 3 to 7 years old are most commonly affected. Recurrent otitis media is defined as three or more distinct episodes in 6 months or four or more episodes in the preceding 12 months with at least one episode in the past 6 months.²

Pathophysiology

Otitis media is a dysfunction of the middle ear and middle ear mucosa.¹ The actual cause is multifactorial, related to anatomy, pathophysiology, and cell biology.¹ Antecedent events may be viral, bacterial, or allergic. Viral upper respiratory tract infections or allergies often precede otitis and result in edema of the eustachian tube and nasopharynx.¹ Narrow eustachian tubes, common in infants and young children, may predispose patients to episodes of otitis media. Exposure to cigarette smoke acts in several ways to increase the individual’s risk for otitis media. Smokers are at higher risk for upper respiratory tract infections, plus the smoke may decrease the mucociliary functioning in the eustachian tube. When middle ear secretions accumulate in the eustachian tube, the opportunity for pathogen growth also increases. Causative pathogens are bacterial and viral. The most common bacterial causative agents are Streptococcus pneumoniae and Haemophilus influenzae. Group A β-hemolytic Streptococcus, Staphylococcus aureus, and Moraxella catarrhalis cause infection on a less frequent basis.¹

Bacteria are the most frequent cause of otitis infections; however, in one study, two thirds of the infections were caused by a combination of bacteria and viruses.¹ This combination complicates recovery because viruses may increase inflammation, decrease neutrophil function, and interfere with antibiotic penetration.

Clinical Presentation and Physical Examination

Thorough otoscopic examination is key to accurate diagnosis of otitis. Clinical findings and severity of symptoms (otalgia and fever) experienced are aligned with criteria for categorizing the types of AOM, distinguishing it from OME and determining treatment. Three 2013 clinical practice guidelines presented by the American Academy of Pediatrics (AAP) consider age, severity of symptoms, otorrhea, and laterality in diagnosing and treating AOM.² These criteria require thoroughness in the physical examination that may not be well received by the child in pain.

Presence of rapid-onset otalgia, worse in a prone position, remains the common initial complaint of patients with AOM. Infants and younger children often have nonspecific symptoms, such as ear rubbing, rhinorrhea, vomiting, diarrhea, and fever. Specific symptoms and signs are linked with causative bacteria. Patients with OME or serous otitis may be asymptomatic or have mild pain with no symptoms of acute infection. Conductive hearing loss is most common. Other symptoms found in this condition include imbalance or vertigo, mild stuffiness, and a fullness or popping sensation in the ear.

History should include incidents (especially recent) of ear infections, upper respiratory tract infections, allergies, smoke exposure, and any treatments and their effectiveness. Examiners also should note development of the current illness, including the onset and duration of symptoms, ear pain or drainage, fever, irritability, hearing loss, tinnitus, and dizziness. Associated symptoms, including headache, eye drainage, nasal congestion, sore throat, and mouth pain, require investigation. Knowledge of activities that involve barometric pressure changes, such as scuba diving and flying, is helpful because these may affect equilibrium and cause discomfort from air in the middle ear. As with any infectious process, the patient’s immune status must be considered.

Body temperature and other vital signs may be within normal range, or the temperature may be elevated. The findings on examination of the mouth, eyes, and nose may also be normal, or the patient may show signs and symptoms of upper respiratory tract infection. The frontal and maxillary sinuses often are tender on palpation and do not transilluminate. Mild to significant lymphadenopathy may be present with warm, tender, and enlarged posterior auricular and cervical lymph nodes.

Diagnosis of AOM requires thorough assessment with pneumatic otoscopy and adherence to defined diagnostic criteria. AAP guidelines² address and discourage the not uncommon practice of deferring aggressive visualization of the tympanic membrane (TM) and relying on symptomatology. The presence or absence of TM bulging is considered critical to accurate diagnosis and discrimination between AOM and OME.²^,³

Cerumen removal may be necessary to obtain a clear view of the TM. The operating head of an otoscope provides direct visualization of the canal and access to remove the cerumen with a small plastic disposable ear curette.³ Irrigation may be used in the absence of TM perforation. Hard or flaky cerumen can be softened with a variety of products at room temperature (e.g., sodium docusate solution, hydrogen peroxide, mineral oil) before removal with a curette removal, irrigation with soft bulb syringe, or use of a low-pressure water stream (Waterpik is a common choice).

Ideally, the otoscope uses a bright light source and airtight seal, usually achieved with the proper-size speculum. Nondisposable speculums are recommended for best seal and light conduction, as well as less painful examinations.²^,⁴ The importance and challenge of differentiating AOM from OME with and without effusion is commonly acknowledged. Web-based resources are available to improve examiner skills.⁴ The interactive online learning site Enhancing Proficiency in Otitis Media (ePROM) is found at http://pedsed.pitt.edu/34_viewPage.asp?pageID=527326406.⁴ Other findings include fluid behind the TM, which often affects the color, and fluid levels may be visible behind the membrane. Discharge in the canal without acute otitis externa suggests perforation. Purulent discharge in the ear canal may be sampled for culture and used as a basis for antibiotic selection. Bullae between the TM layers are most often associated with Mycoplasma pneumoniae.

Diagnosis of AOM requires bulging of the TM with obscured landmarks or new onset of otorrhea not caused by acute otitis externa.² Findings of moderate to severe bulging without other signs or mild bulging and recent (less than 48 hours) onset of ear pain or intense erythema of TM also quality for AOM diagnosis. Presence of MEE also is necessary for diagnosis of AOM. Fluid levels or air bubbles may be seen behind the TM, indicating accompanying effusion, though definitive diagnosis relies on pneumatic otoscopy and/or tympanometry.²

Pain assessment is necessary for both determining the presence of AOM and the need for pain relief. AOM usually is characterized by a throbbing, painful earache with impaired hearing. The Acute Otitis Media Severity of Symptom Scale (AOM-SOS) provides a seven-item, parent-reported symptom score.⁵ Symptoms evaluated are ear-tugging, rubbing, and holding; excessive crying; irritability; difficulty sleeping; decreased activity, decreased appetite; and fever. The validated scale correlates with both the diagnosis and symptoms over time. Fever is often present, and the patient may have nausea or dizziness. The disease usually is accompanied by cold or influenza symptoms.¹^,⁴

In OME, fluid is present in the middle ear without signs or symptoms of acute infection. The TM often is dull gray, although it may appear injected.¹^,²^,⁶ Ear pain may still be present in infants, although it tends to be milder and often intermittent. Older children may report ear fullness and/or an ear popping sensation. Balance problems or hearing loss also may be noted. School performance may be affected. In chronic serous otitis, the TM may appear retracted and amber or bluish in color with a diffuse light reflex. TMs usually have limited movement, and bubbles or a fluid line is seen behind the membrane.

Diagnostics

Determine TM position or contour, color, translucency, and mobility.²^–⁴ Positions other than the usual neutral include retracted, full, and bulging. Moderate to severe bulging is the most important characteristic for the diagnosis of AOM.² Otorrhea may indicate MEE, especially if accompanied by abrupt relief of pain. Retraction is a common finding in OME.

Color options vary widely. The color of the TM may range from gray to red. Erythema of the TM often occurs in AOM, though it may be related to crying or fever. A very white TM may be the result of scarring from previous infections or purulence behind the TM. Translucency may be obscured and cloudy or opaque with illness. Decreased or absent mobility, determined by pneumatic otoscopy, indicates the presence of MEE and is one of the necessary criteria for accurate diagnosis of AOM.²^,⁴

Cerumen removal may be necessary for adequate visualization of the TM. Tympanometry may help with diagnosis if otoscopic examination cannot determine whether there is fluid in the middle ear.⁴ Acoustic reflectometry, the use of sound waves to determine TM mobility, may also be helpful for diagnosis, although it is rarely used.

Examination of the ear canal for otorrhea in the absence of external otitis media is necessary for classification of AOM. Temperature should be checked for presence of fever (above or below 39° C or 102.2° F).

Pain level (severe versus mild) may be determined by parental report in young children. The AOM-SOS is a sensitive option for evaluation.⁵

Weber and Rinne tests may be indicated to determine whether conduction and sensorineural hearing have been affected.

Laboratory or further diagnostic testing is not indicated for most patients with otitis media. There are special considerations for some patients, however.³

• A sinus x-ray study or a computed tomography (CT) scan of the sinuses may be indicated for patients who have recurrent or chronic otitis media, especially if intratemporal or intracranial complications are suspected. A contrast-enhanced CT scan of the temporal bones is the imaging study of choice.

• Allergy testing should be considered in patients who have recurrent or chronic otitis symptoms and a history of allergies or allergic rhinitis. Immune status should be considered in patients with atypical otitis media or those who do not respond to therapy.

• A complete blood count (CBC) with differential should be ordered in immunocompromised patients.

• Tympanocentesis may be indicated for recurrent otitis media to identify causative organisms.

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