7.1.2 External and Middle Ear Conditions Flashcards
What are some common conditions that affect the external acoustic meatus?
Wax/ foreign bodies
Otitis externa- causes pain, discharge, temporary hearing loss and general irritation (swimmer’s ear, ideal environment for bacterial growth)
What is a rare complication of otitis externa?
Can have malignant otitis externa, rare but extremely serious, life threatening, higher risk if immunocompromised e.g. diabetes
Label the image
How do you differentiate between right and left tympanic membranes with an otoscopic view?
Use cone-shaped light reflection
Left- 7-8 O’clock position
Right- 4-5 O’Clock position
If 6 O’clock is midway, 5-4 is on the right side and 7-8 is on the left side
What are some common tympanic membrane abnormalities?
Bulging secondary to bacterial acute otitis media, pus and exudate build up, causes lateral bulging
Retracted and evidence of fluid within middle ear otitis media with effusion
Infection not underlying issue, middle ear normally air filled, effusion leads to air bubbles which increases negative pressure causing it to be sucked inwards
White plaques tympanosclerosis, pervious injury to tympanic membrane
What is a cholesteatoma?
Retraction of pars flaccida (TM) forming a sac/pocket
What is the function of the eustachian tube?
Equilibrates pressure in the middle ear to atmospheric pressure via connection with nasopharynx
What causes a cholesteatoma?
Usually secondary to chronic eustachian tube dysfunction, negative pressures pulls the pocket into the middle ear
-Stratified squamous epithelium and keratin becomes trapped
-Proliferates forming cholesteatoma
Painless, often smelly otorrhea (ear discharge) may have hearing loss
Picture explaining cholesteatoma
What can happen with a cholesteatoma?
Not malignant but slowly grows and expands, can potentially erode bones due to enzymatic bony destruction
e.g. ossicles mastoid/petrous bone, cochlea
