Causes of Hearing Loss in Children
Otitis Media (ear Infections)
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Congenital Causes
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Acquired Causes
Otitis Media
What is otitis media?
Otitis media is an inflammation in the middle ear (the area
behind the eardrum) that is usually associated with the buildup
of fluid. The fluid may or may not be infected.
Symptoms, severity, frequency, and length of the condition
vary. At one extreme is a single short period of thin, clear,
noninfected fluid without any pain or fever but with a slight
decrease in hearing ability. At the other extreme are repeated
bouts with infection, thick "glue-like" fluid and
possible complications such as permanent hearing loss.
Fluctuating conductive hearing loss nearly always occurs with
all types of otitis media. In fact it is the most common cause of
hearing loss in young children.
How common is otitis media?
Otitis media is the most frequently diagnosed disease in
infants and young children (1). Seventy-five percent of children
experience at least one episode of otitis media by their third
birthday. Almost one-half of these children will have three or
more ear infections during their first 3 years of life (2).
Health costs for otitis media in the United States have been
reported to be $3 billion to $5 billion per year (3).
Why is otitis media so common in children?
The eustachian tube, a passage between the middle ear and the
back of the throat, is smaller and more nearly horizontal in
children than in adults. Therefore, it can be more easily blocked
by conditions such as large adenoids and infections. Until the
eustachian tube changes in size and angle as the child grows,
children are more susceptible to otitis media.
How can otitis media cause a hearing loss?
Three tiny bones in the middle ear carry sound vibrations from
the eardrum to the inner ear. When fluid is present, the
vibrations are not transmitted efficiently and sound energy is
lost. The result may be mild or even moderate hearing loss.
Therefore, speech sounds are muffled or inaudible.
Generally, this type of hearing loss is conductive and is
temporary. However when otitis media occurs over and over again,
damage to the eardrum, the bones of the ear, or even the hearing
nerve can occur and cause a permanent, sensorineural hearing
loss.
Can hearing loss due to otitis media cause speech and
language problems?
Children learn speech and language from listening to other
people talk. The first few years of life are especially critical
for this development.
If a hearing loss exists, a child does not get the full
benefit of language learning experiences.
Otitis media without infection presents a special problem
because symptoms of pain and fever are usually not present.
Therefore, weeks and even months can go by before parents suspect
a problem. During this time, the child may miss out on some of
the information that can influence speech and language
development.
How can I tell if my child might have otitis
media?
Even if there is no pain or fever, there are other signs you
can look for that may indicate chronic or recurring fluid in the
ear:
- Inattentiveness
- Wanting the television or radio louder than usual
- Misunderstanding directions
- Listlessness
- Unexplained irritability
- Pulling or scratching at the ears
What should I do if I think that otitis media is
causing a hearing, speech, or language problem?
A physician should handle the medical treatment. Ear
infections require immediate attention, most likely from a
pediatrician or otolaryngologist (ear doctor). If your child has
frequently recurring infections and/or chronic fluid in the
middle ear, two additional specialists should be consulted: an
audiologist and a speech-language pathologist.
An audiologist's evaluation will assess the severity of
any hearing impairment, even in a very young or uncooperative
child, and will indicate if a middle ear disorder is present.
A speech-language pathologist measures your child's
specific speech and language skills and can recommend and/or
provide remedial programs when they are needed.
Will my physician refer my child for these special
evaluations?
As a parent, you are the best person to look for signs that
suggest poor hearing. The American Academy of Pediatrics
recognizes this when it states, "Any child whose parent
expresses concern about whether the child hears should be
considered for referral for behavioral audiometry without
delay".
Parents should not be afraid to let their instincts guide them
in requesting or independently arranging for further evaluation
whenever they are concerned about their children' s health or
development.
How can I find an audiologist or speech language
pathologist?
Search ASHA's
online referral database
of certified Speech-Language Pathologists and Audiologists, or
contact the American Speech-Language-Hearing Association's
Action Center, 2200 Research Boulevard #425, Rockville, Maryland
20850. Phone: 800-638-8255 or 301-296-5700.
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Congenital Causes
The term
congenital hearing loss
implies that the hearing loss is present at birth. It can include
hereditary hearing loss or hearing loss due to other factors
present either in utero (prenatal) or at the time of birth.
Genetic factors
are thought to cause more than 50% of all incidents of congenital
hearing loss in children (4). Genetic hearing loss may be
autosomal dominant, autosomal recessive, or X-linked (related to
the sex chromosome).
In
autosomal dominant hearing loss
, one parent who carries the dominant gene for hearing loss and
typically has a hearing loss passes it on to the child. In this
case there is at least a 50% probability that the child will also
have a hearing loss. The probability is higher if both parents
have the dominant gene (and typically both have a hearing loss)
or if both grandparents on one side of the family have hearing
loss due to genetic causes. Because at least one parent usually
has a hearing loss, there is prior expectation that the child may
have a hearing loss.
In
autosomal recessive hearing loss
, both parents who typically have normal hearing, carry a
recessive gene. In this case the probability of the child having
a hearing loss is 25%. Because both parents usually have normal
hearing, and because no other family members have hearing loss,
there is no prior expectation that the child may have a hearing
loss.
In
X-linked hearing
loss, the mother carries the recessive trait for hearing loss on
the sex chromosome and passes it on to males, but not to
females.
There are some genetic syndromes,in which, hearing loss is one
of the known characteristics. Some examples are Down syndrome
(abnormality on a gene), Usher syndrome (autosomal recessive),
Treacher Collins syndrome (autosomal dominant), Crouzon syndrome
(autosomal dominant), and Alport syndrome (X-linked).
Other causes of congenital hearing loss
that are not hereditary in nature include prenatal infections,
illnesses, toxins consumed by the mother during pregnancy or
other conditions occurring at the time of birth or shortly
thereafter. These conditions typically cause sensorineural
hearing loss ranging from mild to profound in degree. Examples
include:
- Intrauterine infections including rubella (German measles),
cytomegalovirus, and herpes simplex virus
- Complications associated with the Rh factor in the
blood
- Prematurity
- Maternal diabetes
- Toxemia during pregnancy
- Lack of oxygen (anoxia)
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Acquired Causes
Acquired hearing loss
is a hearing loss which appears after birth, at any time in
one's life, perhaps as a result of a disease, a condition, or
an injury. The following are examples of conditions that can
cause acquired hearing loss in children are:
- Ear infections (otitis media) (link to specific section
above)
- Ototoxic (damaging to the auditory system) drugs
- Meningitis
- Measles
- Encephalitis
- Chicken pox
- Influenza
- Mumps
- Head injury
- Noise exposure
How can I find an audiologist or speech-language
pathologist?
Search
ASHA's online referral database
of certified speech-language pathologists and audiologists.
References
1. Dhooge, I.J. (2003). Risk factors for the development of
otitis media.
Current Allergy and Asthma Reports,
3: 321-325.
2. National Institute on Deafness and Other Communication
Disorders. (2002).
Otitis media (ear infection)
(NIH Publication No. 974216). Bethesda, MD: Author.
3. Alsarraf, R., Jung, C.J., Perkins, J., Crowley, C. &
Gates, G.A. (1998). Otitis media health status evaluation: A
pilot study for the investigation of cost-effective outcomes of
recurrent acute otitis media treatment.
Annals of Otology, Rhinology and Laryngology, 107: 120-128.
4. Canalis, R.F., & Lambert, P.R. (2000).
The ear: Comprehensive otology.
Philadelphia: Lippincott Williams & Wilkins.
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