Disorders Affecting the Outer Ear Flashcards
How big is an average adult ear?
2.5 cm (1 in) long and 0.7 cm (0.3 in) in diameter
What is the blood supply of the pinna?
Two branches of the external carotid artery
Superficial temporal artery and postauricular artery
Where does the venous drainage for the pinna end?
In the external and internal jugular veins
What are the sensory innervations of the pinna?
Various cervical spinal nerves, branches of the trigeminal nerve, and vagus nerve
A lot of innervations
What makes reconstruction of the pinna difficult?
Intricate and delicate topography and blood supply
Can genetics be a factor in specific auricular deformities?
Yes
What kind of transmission does auricular abnormalities have?
AD or AR
Can auricular deformities be an indication of middle and inner ear abnomalities?
Yes
These may lead to hearing loss or deafness
Good to practice inspection of the outer ear during otoscopy
Can children with auricular abnormalities show a slightly increased risk of concurrent renal abnormalities?
Yes
May require medical/surgical intervention
What is microtia?
Underdeveloped outer ear
Range from agenesis (absence of pinna) to somewhat small ears with atretic canals
Twice as many males affected
The right ear is most often involved
Rarely bilateral
What is the most common finding of microtia?
Sausage like or peanut ear
What is a constricted ear?
The encircling helix is tight
Purely cosmetic
Loop ear and cup ear
What is a loop ear?
An inferior bending of the superior helix
What is a cup ear?
An increase in bowl size
Is each ear unique?
Yes
No two people share the same pinna shape and form
What are auricular appendages?
Like skin tags
Common anomaly
Usually unilateral
May contain skin alone or skin and cartilage
What are auricular appendages often caused from?
Resulting from accessory auricular hillocks from which the pinna develops
Can auricular appendages present with associated hearing loss?
Yes
A complete audiologic evaluation is necessary
What are auricular sinuses/pits?
Usually harmless
Pit-like depression anterior to the pinna
May become blocked with debris or secondarily infected
What might auricular pits result from?
Failed closure of part of the first branchial groove
What can auricular trauma result from?
Thermal injury (burns or frost bite)
Penetrating injury
Blunt injury
Is the pinna susceptible to trauma?
Yes
It is prominent and unprotected
Unlike the eye, it has no protective reflex
What does auricular trauma require?
Antibiotics and tetanus prophylaxis
Sometimes surgical reconstruction
How can auricular hemotomas occur?
Blunt force trauma and contact sports