Ear Disorders Flashcards
What are the 3 parts of the ear?
Outer (external) ear
Middle ear
Inner ear
Describe the outer ear
Auricle (pinna) - directs sound waves into the ear
External auditory canal (EAC)
Describe the middle ear
Made up of the eardrum and 3 small bones called the ossicles (malleus aka the hammer, incus aka the anvil, and the stapes aka stirrup)
Vibrations of the eardrum are picked up by these bones and sent to the inner ear
The eustachian tube is a hollow tube which connects the middle ear with the nasopharynx
The eustachian tube functions as a pressure equalizing valve for the middle ear which is normally filled with air
Describe the inner ear
Houses the sensory and equilibrium system
Consists of the cochlea, vestibule and semicircular canals
Describe the ear of children younger than 3 years old
The EAC is shorter, straighter and flatter than in adults (instillation of eardrop with ear pulled downward and back)
The shape and direction of the eustachian tube is more horizontal than vertical (drainage is more difficult)
Easier entry of nasopharyngeal aspiration into the middle ear, leading to proliferation of bacteria
Helps explain why children suffer from more middle ear infections
Describe the ear of children over 3 years old and adults
The EAC is longer and forms an S shape (instillation of eardrop upward and back)
The eustachian tube lengthens downward as it enters the nasal cavity (design promotes drainage and inhibits aspiration of nasopharyngeal content into the middle ear)
Describe the external auditory canal
Only skin-lined cul-de-sac in the human body
Warm, dark and prone to becoming moist (excellent environment for bacterial/fungal growth)
Skin is very thin (lateral 1/3 overlies cartilage and the rest has a bone base; easily traumatized)
Exit of debris, secretions and foreign bodies is impeded by a curve at the junction of cartilage and bone
Presence of hair (especially thicker hair (older men) which further impedes the debris)
EAC has some special defenses
Failure of the defences or damage of epithelium of the ACH causes otitis externa
What are the defences of the EAC?
Cerumen
Epithelial migration
S shape of canal
Hair located in the canal
What are some outer ear disorders?
Otitis externa (OE)
Cerumen (ear wax) impaction
Water-clogged ears
What is otitis externa?
Inflammation or infection of the external auditory canal (EAC)
Acute diffuse OE is generally referred to as “swimmer’s ear”
Most often unilateral
Symptoms range from pruritus to severe pain and discharge
Pain is often worse with motion of the ear
What is cerumen impaction?
Develops when earwax accumulates in the inner part of the ear canal and blocks the eardrum
Often caused by misguided attempts to remove earwax
What is water-clogged ears?
Excessive moisture in the external auditory canal
What are some middle ear disorders?
Acute otitis media (AOM)
Secretor otitis media
Chronic suppurative otitis media
Otic barotrauma or aerotitis media
Describe acute otitis media
Inflammation or infection of the middle ear
Most often purely viral and self-limiting
Symptoms include acute ear pain, fever and reduced hearing
Ear pain is often unilateral, developing over a few hours
Tugging or pulling on the ears is often described
How is acute otitis media treated?
Topical agents are not used in AOM
Systemic antibiotics may be required
Acetaminophen or ibuprofen analgesia
Local heat application may be beneficial but should be used cautiously in young children
Describe secretor otitis media
Otitis media with effusion
Middle ear space becomes full with sticky effusion which is unable to escape
Describe chronic suppurative otitis media
Involves a perforation (hole) in the eardrum and active bacterial infection within the middle ear space
Describe otic barotrauma or aerotitis media
Also referred to as airplane ear
Pain resulting form increased air pressure
Due to a respiratory infection or mechanical pressure factors such as scuba diving or flying
What are some inner ear dirsorders?
Vertigo (and dizziness)
Ménière’s disease
Tinnitus
What is vertigo?
Vertigo is a feeling that you or your surroundings are moving when there is on actual movement
It is specific type of dizziness and is a major symptom of a balance disorder
Usually accompanied by nausea and vomiting
Often self-limiting
Can be accompanied to tinnitus, decreased hearing and ear pain
What are common causes of vertigo?
Common causes include viral infections, inner ear disturbances (Ménière’s disease), ototoxic drugs, trauma to the ear or head, vascular disorders
What is dizziness?
Dizziness refers to a variety of sensations including motion sickness, lightheadedness, fainting, spinning
Includes a number of causes unrelated to ear conditions
Can be drug-induced
What is Ménière’s disease?
Believed to be result from fluctuating pressure of the fluid within the inner ear
Increased pressure in the labyrinth (organ of balance)
Cause is not yet understood
Referral is necessary/often drug-induced
What are symptoms of Ménière’s disease?
Vertigo, nausea and vomiting, feeling of fullness/pressure in the ear, fluctuating hearing loss, tinnitus
What is tinnitus?
Continuous or intermittent alien noise in the ear
Can be perceived in one or both ears or in the head
Noise is described as buzzing, ringing, whistling, hissing, ticking or “whooshing”
Most people with tinnitus have hearing loss
Tinnitus often indicates an underlying abnormality rather than being a disease itself
Tinnitus over 24 hours requires a referral
What are the possible causes of tinnitus?
Loud noises for prolonged periods
Impacted cerumen
Airplane ear (pressure/barotrauma)
Chronic otitis media (middle ear infection)
Drug-induced causes (alcohol/NSAIDs)
Stimulants, caffeine, and nicotine may often worsen existing problem
What are ototoxic drugs?
Many ototoxic drugs can lead to both tinnitus and vertigo problems
Generally categorized as: high risk agents and low risk agents
What are some high risk ototoxic agents?
Aminoglycosides
Antineoplastics
IV diuretics
What are some low risk ototoxic agents?
NSAIDs
Antibiotics
What are otic conditions that must be referred?
Otitis externa (swimmer's ear) Otitis media Hearing loss (sudden) Ear pain (otalgia) Objects in the ear Ear drainage (otorrhea) Tinnitus, vertigo, dizziness over 24 hours Perforated eardrum