978
U N I T 1 0
Nervous System
to reduce the risk of developing OM include minimal
exposure to group settings and avoidance of expo-
sure to passive tobacco smoke.
51
Prevention of OM
during the respiratory illness season has been demon-
strated by immunoprophylaxis with influenza vaccines.
Immunization with pneumococcal vaccine has also
been reported to reduce the incidence of OM, but the
reported overall effect has been small.
51,52
Etiology.
Most cases of AOM follow an uncomplicated
upper respiratory tract infection that has been present for
several days. The most common bacteria in AOM are
S.
pneumoniae,
nontypeable
H. influenzae,
and
Moraxella
catarrhalis.
51
The overall incidence of these pathogens
has changed with widespread use of the conjugate
pneumococcal vaccine, with nontypeable
H. influenzae
replacing
S. pneumoniae
as the most common pathogen.
51
Evidence of respiratory viruses is also found in the middle
ear exudates in children with AOM, either alone or, more
commonly, in association with pathogenic bacteria. Of
these viruses, rhinovirus and respiratory syncytial virus
(RSV) are found most often.
51
It remains unclear whether
viruses alone can cause AOM or whether their role is
limited to setting the stage for bacterial invasion and,
perhaps, amplifying the inflammatory response.
The etiologies of AOM and OME are interrelated.
Acute infection is usually followed by residual
inflammation and effusion that, in turn, predisposes
to recurrent infection. Middle ear effusion, which is a
component of both AOM and OME, is an expression of
underlying mucosal inflammation.
Clinical Manifestations.
Acute otitis media is
characterized by an acute onset of otalgia (ear pain), fever,
and hearing loss. Children older than 3 years of age may
have rhinorrhea or a runny nose, vomiting, and diarrhea.
In contrast, younger children often have nonspecific signs
and symptoms that manifest as ear tugging, irritability,
nighttime awakening, and poor feeding. Key diagnostic
criteria include ear pain that interferes with activity or
sleep, tympanic membrane erythema (redness), andmiddle
ear effusion.
50–52
Perforation of the tympanic membrane
may occur acutely, allowing purulent material from the
middle ear to drain into the external auditory canal. This
may prevent spread of the infection into the temporal bone
or intracranial cavity. Healing of the tympanic membrane
usually follows resolution of the infection.
Otitis media with effusion is often an asymptomatic
condition.
51,53
There may be mild intermittent ear pain,
complaints of ear fullness, and “popping.” Secondary
manifestations in infants may include ear rubbing,
excessive irritability, and sleep disturbances. Hearing
loss, evenwhen not suggested by the child, is evidenced by
a seeming lack of attentiveness, behavioral changes, and
failure to respond to conversation-level speech. There
may be problems related to school performance, balance
problems and unexplained clumsiness, or delayed
speech and language development.
52
The duration of the
effusion may range from less than 3 weeks to more than
3 months. Many cases of OME resolve spontaneously,
but 30% to 40% of children have recurrent OME, and
5% to 10% of episodes last 1 year or longer.
52
Diagnosis.
The diagnosis of OM is based on recent and
usually acute onset of symptoms, presence of middle
ear effusion, and signs and symptoms of middle ear
inflammation, including erythema or redness with mild
bulging of the tympanic membrane and otalgia or ear
pain. Younger, nonverbal children with OMmay present
with holding, tugging, or rubbing of the ear. Nonspecific
symptoms may include excessive crying, fever, or
changes in sleep or behavior patterns.
54
Other evidence
of infection includes mild bulging of the tympanic
membrane, onset of ear pain of less than 48 hours, or
intense redness of the tympanic membrane.
Both AOM without otorrhea (drainage from the ear)
and OME are accompanied by otoscopic signs of middle
ear effusion—namely, the presence of at least two of
three tympanic membrane abnormalities: white, yellow,
amber, or occasionally blue discoloration; opacification
other than scarring; and decreased or absent motility.
With OME the tympanic membrane is often cloudy
with distinct impairment of mobility, and an air–fluid
level or bubble may be visible in the middle ear. The
overall importance of distinguishing normal ear status
from AOM versus OME is avoidance of unnecessary use
of antibiotics along with the potential of adverse effects
and antimicrobial resistance.
The diagnosis of AOM can also be confirmed using
tympanometry or acoustic reflectometry. A
tympano-
gram
is obtained by using a small probe that is placed
snugly into the external ear canal. A sound stimulus gen-
erator then transmits acoustic energy into the canal, while
a vacuum pump introduces positive and negative pres-
sures into the ear canal. A microphone in the instrument
detects returning sound energy. The tympanogram pro-
vides a determination of the degree of negative pressure
present in the middle ear. It detects disease when present
but is less reliable when disease is absent.
Acoustic reflec-
tometry
detects reflected sound waves from the middle
ear and provides information on whether an effusion is
absent or present. Increased reflected sound correlates
with an increased likelihood of effusion. This technique
is most useful in children older than 3 months, and its
success depends on user technique.
Tympanocentesis (puncture of the tympanic
membrane with a needle) may be done to relieve pain
from an effusion or to obtain a specimen of middle
ear fluid for culture and sensitivity testing. In instances
where the tympanic membrane has perforated with
resultant drainage into the external ear, a specimen can
be obtained and microbiologic studies can be done to
identify the organism.
Treatment.
The treatment of AOM focuses on symptom
control and management of the underlying pathologic
process. A number of options for pain management
are available, including the local application of heat
and use of analgesic drugs such as acetaminophen and
ibuprofen.
51
Myringotomy (incision in the tympanic
membrane) can be used for relief of pressure in the child
with severe pain, providing almost immediate relief.
The extensive use of antimicrobial agents contributes
to the development of bacterial resistance. Observation
without antimicrobial agents is an option in a child
