Acute Otitis Media, by Alex Ruan and Dr. Jennifer Cheng.
Learning Objectives.
By the end of this video, the student
will be able to describe the common risk factors
and basic epidemiology of acute otitis media;
understand the interplay of anatomy and microbiology
as it relates to the pathophysiology of the illness;
differentiate between acute otitis
media, otitis media with effusion,
and middle ear effusion; recognize
the common clinical presentation,
describe the ear exam, understand diagnostic criteria,
and create a differential for otitis media and otalgia;
understand the basics of acute otitis media management.
Introduction and Definitions.
Acute otitis media is a very common reason for sick visits
and antibiotic administration in the pediatric population.
It is most prevalent among children between 6
and 24 months old.
And more than 80% of children have at least one episode
of otitis media by the time they reach school age.
Besides young age, other risk factors
include family history, presence of siblings,
daycare attendance, tobacco smoke, bottle propping,
lower socioeconomic status, and underlying immunodeficiency.
While the incidence of acute otitis media
is increased during the fall and winter,
the overall incidence of acute otitis media
has decreased over time with the introduction
of pneumococcal conjugate vaccine
and more stringent diagnosis guidelines.
It is important to define acute otitis
media, otitis media with effusion,
and middle ear effusion.
The most recent American Academy of Pediatric guidelines
define acute otitis media as moderate to severe bulging
of the tympanic membrane, or new onset of otorrhea
not due to acute otitis externa, accompanied
by acute signs of illness and signs or symptoms
of middle ear inflammation.
Recurrent acute otitis media is defined
as three separate episodes in the last six months,
or four or more episodes in the past 12 months.
Otitis media with effusion is defined
as inflammation of the middle ear
with liquid collected in the middle ear.
Signs and symptoms of infection are absent.
Middle ear effusion simply refers
to fluid in the middle ear and is found in
both acute otitis media and otitis media with effusion.
Anatomy.
The middle ear is the portion of the ear
between the tympanic membrane and the oval window
of the internal ear.
It consists of three ossicles, the tympanic cavity
and the eustachian tube.
The eustachian tube connects the tympanic cavity
to the nasopharynx and normally functions
to ventilate and clear secretions from the middle ear.
Pathophysiology.
The pathogenesis of acute otitis media
typically occurs as follows.
First, the child develops a viral upper respiratory
infection, or some other preceding infection.
This then leads to inflammation and edema
of the mucosa of the nose, nasopharynx,
and, because of its connection, the eustachian tube.
This edema leads to the obstruction of the eustachian
tube, which prevents the drainage of middle ear
secretions.
As a result, fluid starts to collect in the middle ear.
Viral upper respiratory infections
are actually one of the most common causes
of such dysfunction.
Viruses and bacteria from the upper respiratory tract
enter the middle ear space through aspiration or reflux.
The microbes then proliferate in this environment,
leading to the signs and symptoms of acute otitis media.
Anatomically, a child's use eustachian tube
is shorter and forms a shallower angle,
thus making it easier for microbes
to ascend to the middle ear.
The three most common bacteria in acute otitis media
are strep pneumoniae, nontypeable haemophilus
influenzae, and moraxella catarrhalis.
Other less common bacteria include group A streptococcus
and staph aureus.
Viruses commonly seen include respiratory syncytial virus,
picornaviruses, coronaviruses, influenza, adenovirus,
and metapneumovirus.
Clinical Presentation.
The presentation of acute otitis media
depends on the age of the child.
An older child will classically present with rapid onset
otalgia, or ear pain.
More commonly, especially in the young, preverbal child,
the presenting symptoms and signs are more non-specific.
There may be a history of initial upper respiratory
infection symptoms, such as fever, rhinorrhea,
or congestion.
Other symptoms may include irritability or fussiness,
changes in sleep patterns, poor PO intake,
vomiting, and/or even diarrhea.
Otalgia may present as tugging or rubbing of the ear.
Other aspects of the history that should be ascertained
include daycare attendance, recent sick contacts,
history of prior ear infections and whether
or not they were successfully treated,
the presence of antibiotic allergies,
and, as with every sick visit, PO intake and urine output.
Diagnosis.
The diagnosis of acute otitis media is a clinical one.
It depends on being able to visualize the tympanic membrane
with the pneumatic otoscope.
Before examining the ear, start with a review
of the child's vital signs and general appearance.
Is the child febrile, tachycardic, or tachypneic?
Is the child happy and content, in no apparent distress?
Or is the child irritable and lethargic and actively
tugging on his or her ear?
Next, make sure that the child is comfortably positioned.
Older children who are cooperative
can be easily examined on the exam table.
Younger children will generally be
more comfortable in their caregiver's arms
or lying on the exam table with the caregiver by their side.
When using the otoscope, ensure that the hand with the otoscope
is anchored securely against the child's head
to ensure a stable hold and to prevent sudden movement.
When viewing the to tympanic membrane,
try and examine these four characteristics--
contour, color, translucency, and mobility.
What is the contour of the tympanic membrane?
Is it in a neutral position, or is it bulging or retracted?
What is the color?
Is it translucent or opaque?
How mobile is the tympanic membrane with air insufflation?
Normal is typically described as translucent, pearly gray,
in a neutral position without bulging or retraction
with a visible light reflex and good mobility.
The view of the tympanic membrane
may be obstructed by cerumen, and this
should be removed via a curette, gentle suction, or irrigation.
The diagnosis of acute otitis media
requires signs of middle ear inflammation
and presence of a middle ear effusion.
Bulging of the tympanic membrane is the most specific sign
of middle ear inflammation.
Insufflation of air with a pneumatic otoscope
can show decreased mobility, and this
is one of the most sensitive and specific tests
to determine the presence of a middle ear effusion.
In order to perform pneumatic otoscopy,
gently squeeze the insufflator attachment
while observing the movement of the tympanic membrane.
If fluid is present in the middle ear,
membrane movement will be impeded.
In addition to acute otitis media,
the differential diagnosis for a child with otalgia
should include otitis media with effusion, acute otitis externa,
foreign body, and ear trauma.
Management.
Isolation of the causative microbe
is usually not necessary unless the child
is toxic, has an underlying immunodeficiency,
or has a history of failing antibiotic therapy,
as treatment is usually empiric.
Regardless of antibiotic treatment,
age appropriate analgesia is important,
with acetaminophen or ibuprofen typically
being first-line agents.
Antibiotics are indicated for all infants
less than six months, regardless of mild or severe symptoms.
They are also indicated in children six months
or older with unilateral or bilateral acute otitis media
with severe signs or symptoms.
This includes moderate to severe otalgia,
otalgia for at least 48 hours, or a temperature of 39 degrees
Celsius or higher.
Antibiotics are also indicated for children 6 to 23 months old
with bilateral acute otitis media,
irrespective of severe signs or symptoms.
Antibiotics or observation with close follow-up
is indicated for children 6 to 23 months old
with unilateral acute otitis media.
Antibiotics or observation is also indicated
in children 24 months or older with
unilateral or bilateral acute otitis
media with mild symptoms.
Otherwise, watchful waiting is a reasonable option for patients
not meeting these criteria.
With observation, one must ensure close follow-up
and begin antibiotic therapy if the child worsens
or fails to improve within 48 to 72 hours of onset of symptoms.
The first-line antibiotic is amoxicillin,
assuming no beta-lactam therapy in the past month.
No purulent conjunctivitis.
Patients typically start to see symptomatic improvement
within 48 to 72 hours.
If not, a follow-up appointment should
be made for re-evaluation.
In those patients that are successfully treated,
otitis media with effusion is a common sequela
that usually resolves in six weeks without intervention.
Purulent conjunctivitis is typically
caused by nontypeable H flu, which is usually
resistant to amoxicillin, secondary to production
of beta-lactamase.
In these situations, amoxicillin clavulanate
is indicated, given an increased risk of resistance.
If allergic to penicillin, alternatives
include cephalosporins, such as cefdinir or cefuroxime,
or macrolides, such as azithromycin.
Patients with recurrent acute otitis media,
in addition to receiving appropriate antibiotic therapy,
can be referred to an ear, nose, and throat specialist
for consideration of tympanostomy tubes
in order to decrease the risk of hearing loss and speech delay.
Complications of acute otitis media
include hearing loss, balance or motor
issues, tympanic membrane perforation, cholesteatoma,
mastoiditis, meningitis, bacterial abscess,
and cavernous sinus thrombosis.
Summary.
In summary, acute otitis media is a common reason
for pediatric sick visits and antibiotic prescriptions.
It's incidence is higher in the fall and winter months
and is usually preceded by a viral upper respiratory
infection, predisposing to infection of the middle ear
space.
The diagnosis is dependent on seeing
middle ear effusion and a bulging tympanic membrane
or other signs of acute inflammation.
This must be successfully distinguished from otitis media
with effusion, as management may require
antibiotics with high-dose amoxicillin
being the first-line agent.
Proper analgesia is also critical.
Thank you for watching this video on acute otitis media.