+++
Congenital and Acquired Hearing Loss
++
Approximately 1 in 1500 children has a severe to profound hearing
loss at birth or in early childhood. This relatively high incidence,
the high likelihood of significant negative developmental impact
in children with hearing loss, and the significant technological
capabilities to habilitate children with hearing loss have lead
to most developed countries instituting universal newborn hearing
screening protocols. These protocols are designed to identify all
children with hearing loss at an early age so that intervention
can be provided during the critical early periods of speech and
language development.5,6The most common causes
of acquired hearing loss in children is a conductive hearing loss
that results from abnormalities of the middle ear (especially otitis
media and ossicular abnormalities), whereas congenital hearing loss
is often a result of sensorineural deficits.
+++
Pathophysiology
and Genetics
++
eTable 369.1 lists
common causes of congenital hearing loss. Various series estimate
that upward of 50% of these cases are genetic in origin
(eFig. 369.1). Of these patients, approximately
70% have isolated hearing loss as the only phenotypic manifestation
(ie, nonsyndromic hereditary hearing impairment). The remaining
have hearing loss in conjunction with other abnormalities (ie, syndromic
hearing impairment associated with Pendred, Usher, Wardenburg, Brachio-oto-renal,
and other syndromes). In patients with nonsyndromic hereditary hearing impairment,
the vast majority (~80%) display an autosomal-recessive
mode of transmission. Another 15% are estimated to have
an autosomal-dominant mode of inheritance, with the remainder being
X linked or mitochondrial in nature. The known genetic disorders
associated with hearing loss are found in Table
369-1.
++
++
++
++
Studies of large kindreds with hearing loss have identified multiple
genetic loci associated with nonsyndromic hearing impairment. To
date, 21 autosomal-dominant (DFNA) genes, 22 autosomal-recessive
(DFNB) genes, and 1 X-linked (DFN)
gene have been identified. An illustrative example of the clinical
relevance of these genetic discoveries can be seen with the gene GJB2 (gap
junction β-2 protein), which is also known as connexin
26 (CX 26).7 Studies have identified more than
100 different mutations in GJB2 as a cause for
hearing loss. The most common mutation is 35delG, which accounts
for about one third of all mutations. Routine lab testing is now
used to identify CX 26 mutations, which subsequently helps predict
future hearing deterioration and success with cochlear implantation.
Mutations in genes such as SLC26A4, 12SrRNA, MYO7A, OTOF,
and CDH23 are also believed to account for a significant
proportion of hearing loss in the general population.
++
A history of maternal “TORCH” infections (Toxoplasmosis, Other
agents such as Coxsackie virus and Listeria, Rubella, Cytomegalovirus [CMV], Herpes
simplex) during pregnancy can indicate a likely etiology for congenital
hearing loss in a child. Rubella, for example, is particularly associated
with cochleosaccular dysplasia and congenital deafness. Prenatal CMV infection may
account for up to 40% of all children with sensorineural
hearing loss (SNHL) (see Chapter 310). SNHL
is seen in 5% to 10% of children with asymptomatic
CMV infection and in more than 50% of children with symptomatic
CMV infection. A history of maternal drug use during pregnancy may also
be important. For example, isotretinoin causes congenital hearing
loss with associated malformations of the cochlea. Substances such
as alcohol, cocaine, and other “recreational” drugs
may also cause congenital hearing loss. Perinatal factors such as
prematurity, low birth weight, low Apgar scores, and the need for
neonatal intensive care unit (NICU) admission have all been correlated
with SNHL. Complicated delivery with infant anoxia or severe dystocia
requiring forceps delivery may provide insight into the cause of
congenital hearing loss. Traumatic deliveries can cause mastoid
and middle ear damage that result in conductive hearing loss and/or
SNHL.
++
During the very early postnatal period, routine screening of
infants for problems such as hypothyroidism or phenylketonuria is
now commonplace. Therefore, the likelihood of missing these possible etiologies
of hearing loss is minimal. Other risk factors for hearing loss
at this time include hyperbilirubinemia (typically > 17.0 mg/dL),
metabolic defects, and a wide range of hereditary congenital processes
that manifest with hearing loss.
++
The physical examination of the ear in infants should focus on
identifying features that might suggest associated inner ear anomalies.
For example, stenosis or atresia of the external auditory canal
associated with preauricular pits or skin tags can suggest branchio-oto-renal syndrome,
a fairly common congenital deafness syndrome associated with malformation
of the cochlea. Early audiometric testing is essential in suspected
congenital hearing loss. As discussed previously, accurate audiometric
results can be obtained on any age child through behavioral testing
and/or auditory brainstem response (ABR) and otoacoustic
emission (OAE) testing. Figure 369-5 is an
algorithm for the diagnostic assessment and treatment of patients
with either conductive or sensorineural hearing loss.
++
+++
Management of Children
with Confirmed Hearing Loss
++
The management options for children with confirmed hearing loss
have changed dramatically over the past decade. Figure 369-5 provides an algorithm for the evaluation and management
of children with suspected hearing loss, and eFigure 369.2 provides an approach to the management of children with
hearing loss detected at infant screening. Once hearing loss is
confirmed using an age-appropriate audiologic modality described
earlier in this chapter (behavioral audiometry, auditory brainstem
response [ABR], otoacoustic emissions [OAEs]),
evaluation next is focused upon determining if
the hearing loss is due to a sensorineural hearing loss (SNHL) or
conductive hearing loss (CHL).
++
++
Identifying a child SNHL mandates referral to an otolaryngologist
and consideration of vaccination against Streptococcus pneumoniae.
Vaccination is recommended in this population because children with
congenital SNHL have an increased incidence of underlying cochleovestibular
anomaly and a small increased risk of otogenic meningitis. Identificacation
of those children in whom there is progression of the hearing loss
or severe to profound SNHL is a priority because children in these
groups are more likely to require surgical intervention (cochlear
implantation). In children with less severe hearing loss, follow-up
by an audiologist is crucial to monitor for progression of loss,
and to monitor the efficacy of hearing aids. Continued follow-up
by the audiologist and otolaryngologist should continue until children
are able to reliably report hearing changes and are able to engage
in behavioral testing for each ear individually. All children with
sensorineural hearing loss should also undergo opthamalologic evaluation
prior to since over 14% to 20% will have abnormalities.
These are particularly common in children with mutations in GJB2.8 An
electrocardiogram should also be performed to identify those children
with Jervelland Lange-Neilsen syndrome,
which is a rare disorder consisting of profound SNHL and syncopal
episodes resulting from cardia conduction defects (associated with
disorders of KVLQT1 and KCNE1 genes).
++
The timing of imaging and genetic evaluation varies among individual
practitioners. If there is progression of hearing loss or a severe
to profound hearing loss present, imaging of the temporal bone (CT and
MRI are complimentary) and genetic evaluation should be performed
to allow diagnosis of the underlying cause of hearing loss (35% of
deaf children have anomalous cochleovestibular anatomy) or to prepare
for possible surgical intervention. Routine imaging of infants with
SNHL incurs the risk of sedation and radiating the developing central
nervous system for little immediate benefits except in the profoundly
deaf child being assessed for cochlear implantation.
++
Figure 369-5 and eFigure 369.3 show the far simpler algorithm for managing conductive
hearing loss (CHL). CHL occurs when sound transmission is physically
impeded in either the external and/or the middle ear. Evaluation
includes physical examination to assure the external ear canal is
patent. Otoscopy may reveal cholesteatoma, otosclerosis, or an abnormality
of the tympanic membrane, malleus or incus. CT is useful for diagnosis of
abnormalities of the middle ear structure.
++
++
Rehabilitative options include training that emphasizes audition
enhanced by technologic approaches to the development of spoken
language (eg, auditory-verbal or auditory-aural therapy), the use
of manual forms of communication (eg, sign language), or both (eg,
total communication, cued speech). All approaches are directed by
specialized professionals such as auditory verbal therapists or
special education teachers, but they require a significant commitment
by parents and caregivers. The decision of parents and caregivers
to choose oral or manual communication mode for their child is based on
a number of factors, including the severity of the loss, attitudes
about deafness, professional recommendations, and costs.
++
If oralism is desired, hearing aids are prescribed immediately
after the diagnosis of hearing loss is made, even in small infants.9 When
bilateral conductive losses are present (ie, aural atresia/microtia),
a bone conducting hearing aid is prescribed. There is some controversy
about the need for rehabilitation in unilateral CHL and SNHL because
the outcome depends upon a number of other factors. Therefore in
cases of unilateral hearing loss, with documented normality in one
ear, the decision to utilize a hearing aid can be deferred.
++
Most children with hearing loss can be managed fully with hearing
aids that come in an increasingly acceptable array of designs. FM
systems and telecoils allow the children to attend to important
stimuli (ie, teachers, phone conversations, public performances)
and diminish background noise in learning environments. Studies
have shown that even children with normal hearing demonstrate academic improvement
when placed in classrooms equipped with FM systems broadcasting
so as to diminish background noise.
++
The surgical rehabilitation of children with SNHL using cochlear
implants has totally revolutionized our management during the past
decade.10 The cochlear implant is a device that
digitizes acoustic information and converts it to an electrical
signal that is then sent into the cochlea, where stimulation of
the auditory system occurs. The auditory system is tonotopic along
its entire course through the cochlea, auditory nerve, and brainstem
and even up to the cortex, thus making stimulation of the surviving
spiral ganglion and auditory nerve fibers at discrete locations
within the deaf cochlea sufficient to allow auditory perception
of specific frequencies and patterns of sound. Remarkably, the human
can quickly and reliably make use of this information and codify
speech and language because the child’s auditory system
is tremendously plastic, and there exist sensitive periods within
which, development can maximally occur to increase the chance that
the child will obtain oralism (spoken language without nonauditory
cues). Capitalizing on this plasticity has led to routine early
implantation, with surgery commonly being performed on children
as young as 8 months of age. The linguistic performance achieved
by these children born profoundly deaf and implanted early are astounding
with well more than 80% attending first grade in a mainstream classroom
setting. Bilateral cochlear implantation provides possibly an even
better way of allowing optimal auditory development, in this case
for binaural auditory fusion of the auditory environment in the
central auditory system.11 Early study results
show improved speech in noise and some improvement in the ability
to localize sounds in space after bilateral implantation.
++
Management options for CHL have also undergone significant advances
recently with the introduction of bone anchored hearing aids (BAHA).12 Initially
indicated for bilateral congenital CHL (aural atresia/microtia [eg,
Treacher-Collins syndrome], syndromic CHL without atresia [eg,
branchial-oto-renal syndrome]), BAHA is now more liberally applied
based on its success and is used in the rehabilitation of CHL due
to bilateral cholesteatoma, chronic suppurative otitis media, and
even in some cases of unilateral SNHL to remove the head shadow
effect. Application in some children with nonresolving (permanent)
otitis media with effusion (eg, Down syndrome) has been shown to
be tremendously successful. These implants consist of a titanium
fixture that is implanted into the skull posterosuperior to the
external auditory canal (or where it will be after microtia repair)
and allowed to osseointegrate. In children, the interval between this
first surgical stage and the second (the interstage interval) is
determined by the thickness of the cortical bone (the thinner the
bone, the longer the interval). At the second surgical stage, the
skin is thinned, elevated, and then replaced, but now with a steel
abutment penetrating through it; on this abutment, after healing
of the skin has occurred, the BAHA is attached. The BAHA effectively
eliminates CHL and delivers sound at the level of the sensorineural
thresholds (which are almost always near-normal in congenital CHL
in children). There are new middle ear implants that will be available
in the next decade; however, they are not yet durable enough to
routinely implant them into children, and BAHA remains the standard
prosthetic surgical option for these children.
++
Vertigo often presents with a complaint of “dizziness.” The
approach to diagnosis is outlined in Figure 369-6.13 Differentiating
the variety of experiences that may be
termed “dizziness” by a child or parent is challenging.
Even adults have difficulty describing the experience of a vertiginous
attack accurately. In a child, vertigo may not be described at all
but rather may be reflected in unusual behaviors. Sudden falls,
grasping for support, or even an unwillingness to move can all represent
signs of vertigo. True vertigo implies an overwhelming sensation
of the world spinning, often accompanied with nausea and vomiting. “Dizziness” that
is sometimes seen with postural hypotension or cardiac arrhythmias
is often not related to vertigo. Similarly, a history of visual
disturbance rarely supports a diagnosis of vertigo. The history
should include questions regarding accompanying ear symptoms and
other systemic symptoms. A review of systems should address possible
head trauma or barotrauma that may result in a perilymphatic fistula.
The family history should focus on any family members with migraine
or seizure disorders because either (especially migraine) can present
with vertigo as a primary symptom in children.
++
++
Physical examination findings of pigmentary lesions or neurofibromas,
signs of trauma, abnormal facies, or congenital abnormalities of the
external ear or eyes are meaningful. The otologic exam must rule
out middle ear disease as a possible cause for the vertigo. Acute
otitis media (AOM), otitis media with effusion (OME), or chronic
suppurative otitis media (CSOM) can cause vertigo or, more frequently, a
subtle compromise of balance. Cranial nerve deficits suggest possible
brainstem lesions or tumor as an etiology. Abnormal visual tracking, convergence,
or saccades as well as spontaneous nystagmus are important findings
in a child with vertigo. Simple tests of balance and coordination
are extremely informative in children. Tasks such as hopping on
one foot, performing a tandem gait, standing on a foam cushion,
or simply standing from a seated position on the floor may uncover
neurologic deficits. Repeating the tasks with eyes closed helps
identify those children who have compensated for vestibular deficits
by relying on visual cues.
++
Causes of vertigo are most easily considered as being of either
a central or a peripheral etiology (Table 369-2).
Congenital anomalies, central nervous system infections or neoplasms,
trauma, and vascular anomalies may present with vertigo. Peripheral
disorders involve the labyrinth or eighth nerve. These can either result
from congenital abnormalities or may be acquired. The most common
peripheral disorders causing vertigo in a child include a posttraumatic
perilymphatic fistula (a leakage of inner ear fluid into the middle
ear, usually from the oval or round windows), ototoxic medications,
cholesteatoma, otitis media, benign positional vertigo, and benign
paroxysmal vertigo of childhood. True Ménière’s
disease in children is very rare.14 Although the
underlying etiology should be addressed when possible, temporary
symptomatic improvement may be obtained with vestibular suppressants
such as diazepam or meclizine. This also applies in cases in which
the underlying etiology is unclear. Systemic steroids may be of
benefit with central neoplasms and demyelinating disorders, viral
labyrinthitis, vestibular neuronitis, and syphilitic inner ear disease.
Based on the history and physical examination, appropriate hematologic
and serologic tests, audiovestibular testing, imaging studies, or
electroencephalographic (EEG) studies can be performed to help pinpoint
a likely diagnosis. All patients with vertigo should undergo routine
audiologic testing. Because of the anatomic, physiologic, and pathologic
associations of hearing loss with vestibulopathy, audiologic studies
often provide either diagnostic or supportive data for a diagnosis.
Similarly, electronystagmography (ENG) is a critical diagnostic
tool for evaluating a child’s vestibular function. Other
tests that are helpful are moving platform posturography (MVP),
to attempt to quantify balance and the vestibular evoked myogenic
potential test (VEMP); this test assesses the vestibulospinal pathway
by means of acoustic or galvanic stimuli. The functional status
of the vestibular system as measured by ENG can help distinguish
central from peripheral etiologies, identify asymmetries in responses
of a patient’s inner ears, and define the percentage reduction
in vestibular response for a pathologic inner ear. Potentially useful
laboratory tests include a spot glucose to rule out diabetes or
hypoglycemia, electrolyte studies, thyroid function tests, and serology
for HIV-1, Borrelia burgdorferi (Lyme disease pathogen), Mycobacterium
tuberculosis, and Treponema pallidum (FTA-ABS).
++
++
Labyrinthitis refers to an inflammatory process involving the
inner ear (membranous labyrinth). Accordingly, the manifestations
of labyrinthitis are typically vertigo, hearing loss, and tinnitus.
The severity of symptoms correlates with the intensity and etiology
of the inflammatory process in the inner ear. In cases of serous labyrinthitis,
symptoms are typically mild, with the child complaining of “dizziness” without any
substantial hearing loss. Most cases of serous labyrinthitis are
associated with concomitant acute or chronic otitis media.
++
Management of children with serous labyrinthitis is symptomatic
and supportive, with treatment of the middle ear disease if present.
In contrast, viral labyrinthitis is often associated with a preceding
systemic viral illness or upper respiratory tract infection. Patients
often report a sudden onset of vertigo or progressive dizziness. Sensorineural
hearing loss (SNHL) is rarely a feature of viral inner ear infection
in children. The use of corticosteroids may be beneficial. Usually,
symptoms abate over 1 to 2 weeks.
++
Bacterial labyrinthitis is usually a consequence of meningitis
and presents as a much more acute process than serous labyrinthitis, with
severe vertigo and acute hearing loss. Inoculation of the inner
ear fluids by pathogenic bacteria through preformed pathways and/or
the cerebrospinal fluid is the most likely mechanisms of infection.
Loss of cochlear and vestibular hair cells, secondary scarring,
and ossification of the labyrinth often follow bacterial labyrinthitis,
which explains why spontaneous recovery of hearing is unlikely.
If bacterial labyrinthitis is suspected, parenteral antimicrobial therapy
is indicated, along with antiemetics. When this condition is seen
in conjunction with other acute infectious processes such as meningitis,
treatment is directed at the primary pathologies.
++
Neoplasms of the ear are rare in childhood, with benign lesions
being far more common than malignancies. Osteomas can present as
smooth bumps or masses in the external auditory canal (Fig.
369-7). These are most commonly noted in swimmers and result
from cold-water exposure. Exostoses are also benign bony outgrowths
in the external canal and require intervention only if they occlude
the canal, causing hearing loss or other problems. Although middle
ear masses are unusual in the pediatric population, anatomic variants
sometimes masquerade as masses. For example, aberrant internal carotid
arteries sometimes present as a reddish pulsatile mass through the
tympanic membrane on otoscopy. Similarly, a bluish mass seen in
the middle ear space by otoscopy may represent a high-riding jugular
bulb. Such lesions can cause middle ear symptoms, including hearing
loss, otalgia, and otorrhea. Any suspected middle ear mass should
be evaluated by imaging studies. Eosinophilic granuloma has been
reported to manifest in the temporal bone, and other lesions such
as histiocytosis, rhabdomyosarcomas, and lymphomas may also present
atypically as ear disease. Leukemic or lymphomatous involvement
of the petrous apex marrow spaces has also been reported as a site
of neoplastic disease in children. Ear-specific sequelae of neoplasms
of the ear include facial paralysis, refractory otalgia, and otorrhea.
++
++
Inner ear tumors seen in the pediatric population most commonly
involve the seventh and eighth cranial nerve complexes. Facial nerve
neuromas or hemangiomas of the geniculate ganglion of the facial
nerve represent temporal bone neoplasms that would likely present
as facial nerve dysfunction. Pediatric patients with neurofibromatosis
type II often have dizziness or hearing loss. These tumors often
present bilaterally. Early identification of this disease and surgical
intervention may allow preservation of hearing and facial nerve
function in these patients.
++
Many commonly used over-the-counter and prescription medications
can cause damage to the inner ear. The manifestations of ototoxicity can
include hearing loss, tinnitus, and vestibulopathy, with different
drugs causing one or more of these symptoms depending on the pharmacologic
properties of the particular drug. For many drugs, ototoxicity is
a well-known risk, and the benefits of treatment must be weighed
against the risks of their use to the inner ear. A partial list
of drugs that have ototoxic potential is shown in Table
369-3.
++
++
Several groups in the pediatric population require increased
vigilance for signs of ototoxicity. The high neonatal incidence
of serious gram-negative infections such as sepsis, meningitis,
and pneumonias requires the frequent use of potentially ototoxic
medications. In part, this explains the high risk of ototoxicity
in children with a history of prematurity and neonatal intensive
care unit admission. It has been reported that some patients who
have undergone renal or other organ transplants also show a higher
incidence of hearing and balance disorders; however, it is unclear
as to whether inner ear problems result from the frequent need for
ototoxic medications or dialysis in these patients. Children with
cystic fibrosis often require aminoglycosides for exacerbations
of their pulmonary disease. Finally, children receiving chemotherapy are
also at increased risk for inner ear damage from chemotherapeutic
agents. Cisplatin, for example, has a well-documented effect on
cochlear hair cells and is most commonly associated with a high-frequency hearing loss.
++
Drugs such as aspirin and other salicylates demonstrate reversible
ototoxicity if stopped in a timely manner after onset of inner ear
symptoms. Furosemide alone has been reported to cause sensorineural hearing
loss (SNHL), but it has also been shown to potentiate the ototoxic
effects of other drugs such as aminoglycosides. Occasionally, the
macrolides (erythromycin, azithromycin, clarithromycin) have been
reported to be associated with hearing loss; this is usually reversible.
Complaints of subjective hearing loss, tinnitus, or disequilibrium
may be the earliest signs of ototoxicity. Patients at high risk should
undergo routine audiologic testing before, during, and after treatment
to measure and document any hearing changes. Similarly, serial electronystagmography
(ENG) testing may be useful in cases of vestibulotoxicity.
++
Many eardrops contain potentially ototoxic components, whether
the active ingredients, solutes or preservatives. However, documented cases
of permanent SNHL or vestibulopathy resulting from ototoxic medications
are rare. Currently, the mainstay of topical otic therapy uses fluoroquinolone
eardrops (Floxin and Ciprodex). These are not ototoxic and may be
used safely even in the middle ear via a tympanostomy tube or tympanic
membrane perforation.
++
Acute otitis media (AOM), otitis media with effusion, and complications
of otitis media including chronic suppurative otitis media and mastoiditis
are discussed in Chapter 243.
++
A cholesteatoma is an expanding epithelial-lined sac containing
squamous debris, often infected with purulent discharge. Cholesteatomas
may be congenital or acquired. They are uncommon and are characterized
by a pearly-white keratin mass seen in the middle ear space behind
an intact tympanic membrane (Fig. 369-8).
The most commonly affected areas for acquired
cholesteatomas are the attic region, superior to the short process
of the malleus, and the posterior-superior quadrant of the tympanic
membrane in the region of the incudostapedial joint. Congenital
cholesteatomas are most commonly found in the anterior-superior
middle ear space.
++
++
The most likely congenital etiology is the embryologic retention
of an epithelial cell rest in the middle ear space. Acquired cholesteatomas
may occur as the result of perforation or severe tympanic membrane
retraction. Rarely, they can occur at the site of a tympanostomy
tube insertion. Chronic negative middle ear pressure may cause a
segment of weakened tympanic membrane to retract either in the attic
region or in the posterior-superior quadrant. These retractions
can cause the inhibition of the natural epithelial migration of
desquamated squamous debris. Debris may become wet and infected,
producing foul-smelling otorrhea and an expansile mass lesion of
squamous debris. The expansion and destruction caused by cholesteatomas
may be related to inflammatory mediators secreted by the cholesteatoma
itself. Especially in children, who may not complain of the hearing
loss often associated with cholesteatoma, these lesions may grow
quite large before becoming symptomatic.
++
In a patient with a history of chronic otorrhea, pneumatic otoscopy
can help differentiate whether the affected portion of the tympanic membrane
is a perforation or a retraction pocket. It may also be possible
to observe squamous debris or granulation tissue within a perforation
or a retraction pocket. This is suggestive of cholesteatoma. Squamous
epithelium desquamating from a cholesteatoma has an appearance resembling
cheese. This diagnosis is best made with otomicroscopy using an
operating microscope and suction debridement. If a cholesteatoma
is suspected, CT scanning of the temporal bone may provide information
on the size of the mass and whether surrounding landmarks are involved.
++
The treatment of a cholesteatoma involves surgical removal of
squamous epithelium in the middle ear and mastoid. Although several
different surgical approaches are used to achieve this, almost all
of these approaches involve a mastoidectomy. Surgical removal of
cholesteatoma is performed initially. This is followed by second
procedure allowing confirmation of squamous epithelial removal and subsequent
reconstruction of the ossicles. This second stage of treatment is
performed approximately 6 to 12 months after the initial procedure.
++
A cholesteatoma may cause sensorineural hearing loss (SNHL) or
a conductive hearing loss through ossicular erosion. Disequilibrium
may occur if a cholesteatoma has invaded the labyrinth. Cholesteatomas
have the potential for central nervous system complications. In
addition, the potential complications of acute otitis media (AOM)
may occur, particularly facial nerve palsy, meningitis, intracranial
abscess formation, and sigmoid sinus thrombosis.
+++
Tympanic Membrane Perforation
++
Permanent perforations of the tympanic membrane may occur following
extrusion of a tympanostomy tube, following acute otitis media (AOM)
with tympanic membrane perforation or from direct or indirect trauma
to the tympanic membrane. A conductive hearing loss may be the only
symptom of a perforation, although recurrent episodes of otorrhea
may also occur.
++
A small perforation may be asymptomatic or may be associated
with a significant conductive hearing loss. Small perforations aerate
the middle ear in some patients with chronic eustachian tube dysfunction,
in much the same way as a tympanostomy tube. Large perforations
are virtually always associated with a conductive hearing loss.
Perforation of the tympanic membrane warrants audiologic assessment
to estimate the degree of conductive hearing loss. Tympanometry
can confirm the presence of a perforation.
++
In the presence of otorrhea, treatment with topical antimicrobial
eardrops is appropriate. The new generation of quinolone eardrops
is particularly effective and nonototoxic. Obtaining a sample for
culture and sensitivity is appropriate for persistent otorrhea.
Definitive treatment of a tympanic membrane perforation requires
surgical repair. In younger children, it is reasonable to delay
this repair if ongoing eustachian tube dysfunction is suspected.
++
Perforations of the tympanic membrane are usually associated
with conductive hearing loss. This hearing loss is exacerbated if
the perforation overlies the round window membrane. In the presence
of chronic membrane retraction, ossicular discontinuity may also
contribute to hearing loss. Rarely, sensorineural hearing loss (SNHL)
may occur if there has been long-term chronic suppurative otitis media
(CSOM) or external trauma as the cause of the perforation.
++
Otitis externa (OE) is an inflammatory condition of the external
ear, often related to environmental conditions in the outer ear.
The healthy external ear is a self-cleaning environment. Cerumen
is a protective antibacterial and waterproofing agent produced by
the cerumen glands of the outer third of the external ear canal.
Normally, cerumen slowly migrates laterally and spontaneously extrudes.
The medial two thirds of the external ear canal is bony, with a
thin layer of skin that has no cerumen glands. Failure of the cerumen
to extrude spontaneously may be due to a number of factors, including (1)
hearing aid usage in which the ear mold blocks extrusion, (2) cotton-tip
applicator usage where the patient pushes the cerumen medially,
or (3) anatomic abnormalities of the ear canal with narrowing and
subsequent trapping of the cerumen. The actual volume and consistency
of cerumen also affects migration. Pain and conductive hearing loss
are the most common symptoms of OE.
++
The two most common causes of otitis externa (OE) are related
to trauma and water exposure. The most common mechanisms of trauma
include cotton-tip applicators, fingernails, or foreign bodies.
Organic foreign bodies are more irritating than nonorganic foreign
bodies. Insects can be especially problematic. Water exposure may
cause excessive retained moisture due to desquamation of squamous
epithelium and retained cerumen, thus predisposing a child to OE.
Anatomic factors such as canal exostoses may also predispose to
water trapping. Approximately 30% of OE cases as associated with
water exposure, 30% with ear canal trauma and 30% are
idiopathic. The remaining 10% have less common etiologies,
including skin disorders such as eczema or dermatitis. Occasionally,
there may be an infection of the sebaceous glands of the outer third
of the ear canal with formation of a furuncle, which is a small staphylococcal
abscess with symptoms disproportionate to its size. Vesicles of
the ear canal may be associated with herpes zoster infection. The
most common organisms associated with OE are Staphylococcus
aureus or Pseudomonas aeruginosa. Resistance
to treatment may be due to an underlying fungal infection, frequently Candida
albicans.
++
In its initial stages, otitis externa (OE) usually presents with
itching and a sensation of fullness in the ear. This rapidly progresses
to severe pain and associated ear discharge. Blockage of the external
ear canal will cause a conductive hearing loss. Unlike acute otitis
media (AOM), movement of the pinna will greatly exacerbate the pain.
There may be associated pain with chewing. Fever is uncommon. On
physical examination, there may be frank discharge from the ear,
and visualization by otoscopy may be limited either because of pain
or swelling of the external ear canal. In severe cases, the external ear
canal may be completely closed. If a furuncle is present, there
will be localized swelling and erythema with extreme pain on palpation
of the affected area. Whenever possible, it is advisable to inspect
the tympanic membrane to ensure that there is no underlying cause
for the discharge, such as chronic suppurative otitis media (CSOM)
or a perforation following AOM. This may not be possible at initial
assessment because of edema of the external ear canal and associated
pain on inspection. As such, follow-up examination is essential.
++
Otitis externa (OE) requires prompt treatment of both the infective
organism and the underlying cause. Foreign bodies should be removed, the
use of cotton-tip applicators should be discontinued, and the patient
should be advised not to swim. Debris in the ear canal should be removed.
Patients should receive antibiotic eardrops that are effective against
the presumed underlying organisms. Topical steroids may alleviate
the inflammation, pain, and swelling. However, steroid drops should
be discontinued in the presence of a fungal OE. Eardrops should be
administered several times a day in the initial stages. If the external
canal is extremely edematous, placement of a sponge or wick in this
canal is useful to ensure antibiotic penetrance. Systemic antibiotics
are also warranted if there is surrounding cellulitis of the soft
tissues adjacent to the ear or cervical adenitis. Adequate analgesia
is warranted, and in severe cases, narcotic administration may be
justifiable.
++
If OE is unresponsive to initial treatment, a microbiologic sample
for culture and sensitivity should be obtained. The most likely
organisms under these circumstances are multiply drug-resistant P
aeruginosa or fungi. Quinolone eardrops are usually the
most effective treatment for Pseudomonas. Antifungal
drops or creams are indicated for fungal OE. A furuncle may require
topical and systemic antistaphylococcal antibiotics. If the abscess
is pointing, then drainage with an 18-gauge needle may dramatically
alleviate pain.
++
Once the acute infection has resolved, it is prudent to reassess
the ear to ensure that there is no underlying predisposition to
infection such as eczema or a cholesteatoma. In individuals predisposed
to OE, prophylactic measures may be undertaken to prevent recurrence.
This may include treatment of underlying skin conditions, regular
toilet of the external ear canal to prevent water trapping, surgical
removal of bony exostoses, and use of alcohol eardrops after swimming
to promote drainage of water from the ear.
++
Recurrent otitis externa (OE) may be due to canal stenosis, which
requires surgical intervention. Rarely, there may be cerumen and
squamous epithelial retention with ballooning of the bony ear canal (keratitis
obturans). This may also be associated with an underlying ciliary
dyskinesia or congenital or acquired narrowing of the ear canal.
The most serious complication is the development of necrotizing or “malignant” OE.
This is often seen in patients who are diabetic or immunocompromised,
and the offending organism is often pseudomonas. The
infection spreads via the fissures of Santorini, causing osteomyelitis
of the skull base. This osteomyelitis presents with pain and possible
cranial nerve palsies. Patients who do not receive appropriate treatment
have a high mortality rate.
+++
Chondritis and
Perichondritis
++
Perichondritis is an infection of the perichondrium
of the auricular cartilage (Fig. 369-9).
Infection typically follows local trauma (eg, ear piercing, burns,
or lacerations). Occasionally, when the infection spreads down to
the cartilage of the pinna itself, patients may also have chondritis
(eFig. 369.4). The infection
may closely resemble auricular cellulitis, with erythema, swelling,
and extreme tenderness of the pinna, although the lobule is less
often involved in perichondritis. The most common pathogens are P
aeruginosa and S aureus, although other
gram-negative and gram-positive organisms are occasionally involved.
Treatment consists of systemic antibiotics active against both P
aeruginosa and S aureus. An antipseudomonal
penicillin or a combination of a penicillinase-resistant penicillin
plus an antipseudomonal quinolone is typically used. Incision and
drainage may be helpful for culture and for resolution of infection,
which often takes weeks. If perichondritis fails to respond to adequate
antimicrobial therapy, or is relapsing, a noninfectious inflammatory
etiology should be considered such as relapsing polychondritis associated
with rheumatologic disorders.
++
++
++
Blunt trauma to the auricle is a common injury sustained during
athletic activities and routine childhood play. These injuries are
best prevented with the routine use of bike helmets and sport-specific
head protection. Because of the thin skin covering and delicate
perichondrium, hematomas and seromas of the auricle are common.
When undiagnosed or untreated, these injuries can result in auricular
cartilage damage and auricular deformity. Appropriate treatment
consists of drainage of the fluid collection and subsequent application
of a pressure dressing to prevent reaccumulation of fluid. The child
should be reevaluated at close intervals for signs of perichondritis.
The use of prophylactic broad-spectrum antibiotics may be indicated.
++
Penetrating trauma to the ear (most commonly, bite wounds) requires
repair of the soft tissue defect and prophylactic antibiotic treatment.
Because perichondritis is a significant risk that can cause necrosis
of cartilage and substantial auricular deformity, close patient
follow-up is necessary. In rare cases of subtotal avulsion with extensively
exposed auricular cartilage and cartilage of questionable viability,
hyperbaric oxygen treatment may be considered.
++
Frostbite injuries to the auricle are common in colder climates
and should be treated by rewarming the affected area using warm,
sterile saline-soaked gauze. Following this, treatment of the area
should be similar to treatment of a burn, using topical sulfadiazine
and analgesics. Close follow-up for signs of chondritis is essential.
If burns of the auricle are superficial, they may require only topical
treatment with sulfadiazine. More extensive burns may require debridement,
systemic antibiotics, and soft tissue reconstruction.
++
Trauma to the external auditory canal usually involves foreign
objects inserted into the canal. Laceration of the canal skin may
require analgesics but may not require
any specific treatment. In the primary care setting, foreign bodies
in the cartilaginous portion of the canal can typically be removed.
Those located medially in the canal or abutting the tympanic membrane
are difficult to remove and generally require an operating microscope,
suction, and specific otologic instruments. Following removal of
the foreign body, a complete exam of the external auditory canal
and tympanic membrane is necessary to rule out perforation.
++
Traumatic injuries of the middle ear are often caused by direct
trauma via the external auditory canal. The mechanisms of these
injuries include foreign body insertion in the external auditory
canal or “slapping” of the ears. Tympanic membrane
perforation may result in pain, bloody drainage, and hearing loss.
Although these traumatic perforations typically heal over 3 to 4
weeks, trauma can also induce a middle ear effusion and/or
hemotympanum behind an intact tympanic membrane. Such middle ear
effusions clear spontaneously over the course of 10 to 14 days without
treatment; however, careful examination and audiologic testing should
be performed to rule out ossicular damage. In cases in which there
is a significant and persisting conductive hearing loss, middle
ear exploration may be indicated to identify and correct an ossicular
discontinuity. Very rarely, severe trauma results in subluxation
of the stapes footplate into the vestibule of the inner ear. Such
patients present with sensorineural hearing loss (SNHL) and vertigo,
and may require surgical intervention.
++
Barotrauma to the middle ear may result from scuba diving, routine
plane flights, or even from excessively strong Valsalva-type maneuvers
such as sneezing or coughing. Common findings after barotrauma are
a middle ear effusion or hemotympanum. Less frequently, barotrauma
may cause damage to the oval or round windows, resulting in leakage
of perilymphatic fluid, called perilymph fistula. These patients
may present with SNHL with or without vertigo. Perilymphatic fistulas
are difficult to demonstrate intraoperatively and are often treated
empirically after ruling out other pathologies.
++
Injury to the facial nerve via middle ear trauma is exceedingly
rare. It most commonly occurs secondary to temporal bone fractures
with resultant middle ear and mastoid trauma. For a patient presenting with
a history or signs of middle ear trauma and facial paralysis, audiologic
testing, temporal bone imaging, and immediate middle ear exploration
may be warranted.
++
Trauma to the inner ear structures can occur in association with
severe blunt head trauma and temporal bone fracture. Approximately
75% of temporal bone fractures are longitudinal, with the
fracture line running along the long axis of the petrous bone; the
remaining 25% of these fractures are transverse. Although
20% of longitudinal fractures are associated with facial nerve
injuries, up to 80% of transverse fractures may be associated
with such injuries. Fractures through the cochlear or vestibular structures
of the inner ear often cause symptoms of sudden SNHL and vertigo,
and can be difficult to evaluate in severely injured or cognitively
impaired patients. Longitudinal fractures are commonly associated
with fracture lines that cross the external auditory canal and/or
tympanic membrane, resulting in bloody otorrhea or hemotympanum.
Conductive hearing loss secondary to ossicular disruption or fluid (ie,
cerebral spinal fluid [CSF] or blood) may also
result from trauma. Management of CSF and some facial nerve injuries
may require immediate middle cranial fossa and middle ear/mastoid
exploration, whereas other problems such as ossicular discontinuity
and tympanic membrane perforations must wait until the patient can
tolerate an elective procedure.
++
Barotrauma can also cause inner ear damage by inducing a perilymph
fistula. Symptoms of vertigo or worsening hearing loss during times
of intracranial pressure (eg, straining or Valsalva) are typical characteristics
of perilymphatic fistula. Surgically placing soft tissue “patches” over the
oval and round windows provides a simple yet effective treatment
for these patients.