Ears
Dx hearing loss - Three main types of hearing loss: conductive, sensory, and neural.
Most commonly due to cerumen impaction, transient eustachian tube dysfunction
associated with upper respiratory tract infection, or age-related hearing loss.
Conductive hearing loss - results from dysfunction of the external or middle ear.
Four mechanisms of conductive hearing loss - (1) obstruction (eg, cerumen impaction),
(2) mass loading (eg, middle ear effusion), (3) stiffness effect (eg, otosclerosis), and (4)
discontinuity (eg, ossicular disruption)
Common causes conductive hearing loss - most commonly due to cerumen impaction
or transient eustachian tube dysfunction associated with upper respiratory tract
infection.
Persistent conductive losses usually result from chronic ear infection, trauma, or
otosclerosis.
Conductive hearing loss is often correctable with medical or surgical therapy—or in
some cases both.
'sensorineural' - Sensory and neural causes difficult to differentiate due to testing
methodology, referred to as 'sensorineural.'
Sensory hearing loss - results from deterioration of the cochlea, usually due to loss of
hair cells from the organ of Corte.
Sensorineural losses in adults are common. The most common form is a gradually
progressive, predominantly high-frequency loss with advancing age (presbycusis).
Causes of Sensory hearing loss - common causes include excessive noise exposure,
head trauma, and systemic diseases, individual's genetic make-up. Sensory hearing
loss is usually not correctable with medical or surgical therapy but often may be
prevented or stabilized.
An exception is a sudden sensory hearing loss, which may respond to corticosteroids if
delivered within several weeks of onset.
Neural hearing loss - occurs with lesions involving the eighth nerve, auditory nuclei,
ascending tracts, or auditory cortex. It is the least common clinically recognized cause
of hearing loss. Causes include acoustic neuroma, multiple sclerosis, and auditory
neuropathy
,hearing level may be estimated. - by having the patient repeat aloud words presented in
a soft whisper, a normal spoken voice, or a shout.
tuning fork - useful in differentiating conductive from sensorineural losses.
Weber test - placed on the forehead
In conductive losses, the sound appears louder in the poorer-hearing ear, whereas in
sensorineural losses it radiates to the better side.
Rinne test - tuning fork is placed alternately on the mastoid bone and in front of the ear
canal. In conductive losses >25dB, bone conduction exceeds air conduction; in
sensorineural losses, the opposite is true.
audiometric studies - Performed in a soundproofed room. Pure-tone thresholds in
decibels (dB) are obtained over the range of 250-8000 Hz for both air and bone
conduction.
Every patient who complains of a hearing loss should be referred for audiologic
evaluation unless the cause is easily remediable (eg, cerumen impaction, otitis media)
Tx For patients with conductive loss or unilateral profound sensorineural - the bone-
anchored hearing aid uses an oscillating post drilled into the mastoid, directly
stimulating the ipsilateral cochlea (for conductive losses) or contralateral ear (profound
unilateral sensorineural loss).
Tx For patients with severe to profound sensory hearing loss - the cochlear implant—an
electronic device that is surgically implanted into the cochlea to stimulate the auditory
nerve—offers socially beneficial auditory rehabilitation to most adults with acquired
deafness and children with congenital or genetic deafness
Disorders of the auricle - for the most part dermatologic
-Skin cancers
-Traumatic auricular hematoma
-Cellulitis
Skin cancers - due to sun exposure are common and may be treated with standard
techniques.
Traumatic auricular hematoma - must be recognized and drained to prevent significant
cosmetic deformity (cauliflower ear) or canal blockage resulting from dissolution of
supporting cartilage
cellulitis of the auricle - must be treated promptly to prevent development of
perichondritis and its resultant deformity
, Diseases of the Ear Canal - Cerumen Impaction
Foreign Bodies
External Otitis
Pruritus
Exostoses & Osteomas
Neoplasia
Cerumen - protective secretion produced by the outer portion of the ear canal. In most
persons, the ear canal is self-cleansing. Recommended hygiene consists of cleaning
the external opening with a washcloth over the index finger without entering the canal
itself.
Cerumen Impaction - In most cases, cerumen impaction is self-induced through ill-
advised attempts at cleaning the ear
Tx Cerumen Impaction - relieved with detergent ear drops (eg, 3% hydrogen peroxide;
6.5% carbamide peroxide), mechanical removal, suction, or irrigation.
Irrigation is performed with water at body temperature to avoid a vestibular caloric
response (only when the tympanic membrane is known to be intact.)
Foreign bodies - more frequent in children than in adults
Firm materials may be removed with a loop or a hook, taking care not to displace the
object medially toward the tympanic membrane
Aqueous irrigation should not be performed for organic foreign bodies (eg, beans,
insects), because water may cause them to swell
Dx External Otitis - Painful erythema and edema of the ear canal skin.
Often with purulent exudates.
May evolve into osteomyelitis of the skull base, often called malignant external otitis,
particularly in the diabetic or immunocompromised patient.
Hx in External Otitis - history of recent water exposure (ie, swimmer's ear) or
mechanical trauma (eg, scratching, cotton applicators)
PE External Otitis - Examination reveals erythema and edema of the ear canal skin,
often with a purulent exudate. Manipulation of the auricle often elicits pain. Because the
lateral surface of the tympanic membrane is ear canal skin, it is often erythematous.
However, in contrast to acute otitis media, it moves normally with pneumatic otoscopy
