History
The history of acute otitis media (AOM) varies with age, but a number of constant features manifest during the otitis-prone years.
In the neonate, irritability or feeding difficulties may be the only indication of a septic focus. Older children begin to demonstrate a consistent presence of fever (with or without a coexistent upper respiratory tract infection [URTI]) and otalgia or ear tugging. These latter symptoms are not entirely exclusive to AOM; teething pain or pharyngitis (particularly coxsackievirus infection) can mimic these symptoms.
In older children and adults, hearing loss becomes a constant feature of AOM and otitis media with effusion (OME), with reports of ear stuffiness noted even before the detection of middle ear fluid. Otalgia without hearing loss or fever is observed in adults with external otitis, dental abscess, or pain referred from the temporomandibular joint. Orthodontic appliances often elicit referred pain as the dental occlusion is altered.
Physical Examination
There is no substitute for a thorough clinical examination. Pneumatic otoscopy is the standard of care in the diagnosis of acute and chronic otitis media. In AOM, the tympanic membrane normally demonstrates signs of inflammation, beginning with reddening of the mucosa and progressing to the formation of purulent middle ear effusion and poor tympanic mobility. The tympanic membrane may bulge in the posterior quadrants, and the superficial epithelial layer may exhibit a scalded appearance (see the image below).
Tympanic membrane of a person with 12 hours of ear pain, slight tympanic membrane bulge, and slight meniscus of purulent effusion at bottom of tympanic membrane. Reproduced with permission from Isaacson G: The natural history of a treated episode of acute otitis media. Pediatrics. 1996; 98(5): 968-7.
Perforation of the tympanic membrane is not unusual as the process advances, most frequently in posterior or inferior quadrants. Before or instead of a single perforation, an opaque serumlike exudate is sometimes seen oozing through the entire tympanic membrane.
With perforation and in the absence of a coexistent viral infection, the patient generally experiences rapid relief of pain and fever. The discharge initially is purulent, though it may be thin and watery or bloody; pulsation of the otorrhea is common. Otorrhea from acute perforation normally lasts 1-2 days before spontaneous healing occurs. Otorrhea may persist if the perforation is accompanied by mucosal swelling or polypoid changes, which can act as a ball valve.
Pneumatic otoscopy is an important diagnostic tool for differentiating AOM from acute bullous myringitis. The latter condition, in its purest form, manifests 10-14 days after a viral infection and causes severe localized otalgia without middle ear effusion.
The bullae or blebs may contain serous or hemorrhagic fluid and may extend onto the adjacent canal wall. Pain is relieved by puncturing the bleb. Similar blebs may occur in association with AOM. These patients demonstrate more systemic symptoms and continue to have pain associated with purulent middle ear effusion, which persists following rupture of the blebs.
It should be kept in mind that the findings described above apply to patients who are immunocompetent. Children who are immunosuppressed, particularly those undergoing chemotherapy, may not manifest the typical inflammatory responses. In these patients, the simultaneous appearance of systemic sepsis and a serous middle ear effusion might be the only indicators of AOM.
A finding of AOM does not relieve the practitioner of the responsibility to search for coexistent related or unrelated conditions. This responsibility is particularly important when antimicrobial agents are prescribed, in order to ensure appropriate simultaneous coverage of coexistent infections such as AOM with streptococcal pharyngitis or mycoplasmal pneumonia.
Transtympanic measurements of temperature in children with middle ear effusions have been shown to be inconsistent. Accordingly, body temperature should be measured by means of oral, rectal, or axillary methods.
Complications
The complications of AOM are classified by location as the disease spreads beyond the mucosal structures of the middle ear cleft. They may be categorized as follows:
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Intratemporal - Perforation of the tympanic membrane, acute coalescent mastoiditis, facial nerve palsy, acute labyrinthitis, petrositis, acute necrotic otitis, or development of chronic otitis media
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Intracranial - Meningitis, encephalitis, brain abscess, otitis hydrocephalus, subarachnoid abscess, subdural abscess, or sigmoid sinus thrombosis
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Systemic - Bacteremia, septic arthritis, or bacterial endocarditis
Danger signs of possible impending complications include (1) sagging of the posterior canal wall, (2) puckering of the attic, and (3) swelling of postauricular areas with loss of the skin crease.
Pediatric mastoiditis is a rare complication of AOM, with a study by King et al finding that nationally in the United States, between 2000 and 2012, the estimated incidence of pediatric mastoiditis peaked in 2006, at 2.7 cases per 100,000 population, and fell to its lowest point in 2012, at 1.8 cases per 100,000 population. [19]
A study of 177 children aged 6 months to 7 years suggested that recurrent episodes of AOM increase the risk of spontaneous tympanic membrane perforation (STMP). In addition, the study, by Marchisio et al, found a high frequency (50.8%) of nontypeable H influenzae in the middle ear fluid of patients with AOM with STMP, particularly in those with recurrent STMP. M catarrhalis and S pneumoniae (35.0% and 27.1% of cases, respectively) were the next most common bacterial pathogens found in AOM with STMP. [20]
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Healthy tympanic membrane.
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Tympanic membrane of a person with 12 hours of ear pain, slight tympanic membrane bulge, and slight meniscus of purulent effusion at bottom of tympanic membrane. Reproduced with permission from Isaacson G: The natural history of a treated episode of acute otitis media. Pediatrics. 1996; 98(5): 968-7.
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Drawing of normal right tympanic membrane. Note outward curvature of pars tensa (*) of eardrum. Tympanic annulus is indicated anteriorly (a), inferiorly (i), and posteriorly (P). M = long process of malleus; I = incus; L = lateral (short) process of malleus.
