ear disease (see DM) Flashcards
what section of the ear is the tympanic membrane part of
the middle ear - although embryological is is both middle and external ear
what is migration (ear)
the outer layer of the skin lining the ear canal very gradually migrates outwards -> this is how wax and dead skin is naturally removed from the canal
function of the Eustachian tube
equalise the pressure between the middle and outer ear
what epithelium lines the middle ear
respiratory epithelium
what nerve traverses the middle ear
chorda tympani (branch of CN VII) => facial nerve palsies can arise due to ear surgery
what nerves innervate the inner ear
- The auriculotemporal nerve (branch of CN V mandibular) - general sensory innervation to the meatal side of tympanic membrane
- vagus nerve (CN X) - general sensory innervation to the meatal side of tympanic membrane
- The tympanic branches of the glossopharyngeal nerve - general sensory impulses of the mucosal side of the tympanic membrane transmitted
what are the 5 main symptoms of ear disease
- hearing loss
- otalgia (pain)
- otorrhoea (dishcarge)
- vertigo
- tinnitus
what other class of disease can affect the external ear
derm diseases -> the external ear is skin lined and so may present w itchiness, redness, scales, lumps, ulcerations and even skin cancers
5 acquired diseases of the external ear
- haematoma
- exostosis (benign outgrowth of cartilaginous tissue on a bone)
- osteoma
- infection
- foreign body
4 common external ear dformaties
- prominent cup - abnormally protuding ear, may have an incomplete opening of the ear (cup ear deformity)
- stahl’s ear - helix not formed properly, often in combination w other deformities
- lidding/lop ear - folding over the helical rim/upper third of the ear
- helical rim deformity - irregularities or compressions that may occur anywhere along the helix
what is microtia and what are the grades
a congenital condition in which the cartilage of the outer ear is underdeveloped or absent (but normal middle + inner ear)
grade 1 - small but almost normal
grade 2 - some recognisable anaotmy present
grade 3 - small rudiment of soft tissue and no ear canal
grade 4 - no external ear and no ear canal
congenital abnormalities of the external ear (3)
- microtia
- pinna abnormalities
- external canal stenosis
what is an auricular haematoma an what is the consequence of this
the stripping of the perichondrium off the cartilage by blood => nutrients and oxygen can’t reach cartilage (it is avascular itself) -> ischaemia and necrosis leading to permanent deformity
what is perichondritis
an infection of the skin and tissue surrounding the cartilage of the outer ear -> just the cartilaginous part, sparing of the lobe and tragus
what is acute otitis externa
inflammation of the external auditory meatus lasting <6wks
2 common causes for otitis externa
- self cleaning -> cotton buds leading to trauma or foreign body blockage
- swimming (swimmer’s ear -> diffuse bacterial otitis externa)
2 common bacteria causing otitis externa
- pseudamonas aeruginosa
- staphylococcus aureus
what is furunculosis (ear)
acute localised otitis externa
what is otomycosis
fungal otitis externa
what is a severe complication of otitis externa
necrotising otitis externa
what is chronic otitis externa
inflammation of the external ear lasting >3 months
what mico-organisms usually cause chronic otitis externa (2)
- aspergillus
- candida albicans
mgx of chronic otitis externa (5)
- cleaning of ear canal
- topical abx
- steroid drops
- ear hygiene advice (plug ear w Vaseline when going swimming etc.)
- oral abx - if pt is immunocomprimised or infection spread beyond ear canal
what is necrotising otitis externa
a potentially life threatening progressive infection of the external ear canal which may spread to cause osteomyelitis of the temporal bone and adjacent structures
risk factors for otitis externa (7)
- swimming
- skin conditions e.g. eczema, dermatitis
- hot, humid
- trauma
- climates
- tightly fitting hearing aid
- use of ear plug
signs/symptoms of otitis externa (7)
- itch
- pain of the tragus and pinna, possibly the jaw
- ear discharge
- hearing loss (canal occlusion - rare)
- red ear canal
- tender regional lymphadenitis
- scaly ear canal (chronic)
what organism commonly causes NOE
psuedamonas aerogenosa
5 diseases of the middle ear
- acute otitis media
- chronic otitis media (incl. cholesteatoma)
- ossicular chain dysfunction
- otosclerosis
- trauma/iatrogenic
what is acute otitis media
inflammation of the middle ear <6wks
what are the common causes of acute otitis media
80% viral - usually URTI related
bacteria - H.influenzae, S.aureus, Moraxella catarrhalis
risk factors for acute otitis media (7)
- young age
- smoking/passive smoking
- nursery attendance
- formula feeding (breastfeeding has a protective effect)
- craniofacial abnormalities (e.g. cleft palate)
- use of a dummy
- prematurity
etc.
suppurative vs non suppurative otitis media
suppurative - chronic inflammation of the middle ear and mastoid cavity, which presents with recurrent ear discharges (otorrhoea) through a tympanic perforation for at least 2 weeks;
non suppurative - A otitis media which involves transudation of fluid in the middle ear without pus formation
2 types of chronic suppurative otitis media
- tubotympanic -> mucosal, safe
- atticoantral -> squamous, unsafe
3 types of chronic non- suppurative otitis media
- effusion
- atelectasis
- adhesion
what is atelectasis otitis media
a condition of retraction and atrophy of the tympanic membrane in chronic otitis media with effusion
what is adhesion otitis media
a condition in which the tympanic membrane is depressed and adheres to the fibrous scar tissue caused by chronic inflammation in the inner wall of the middle ear cavity, resulting in the loss of aeration in the tympanic cavity
what is glue ear
otitis media with effusion
what is mucosal chronic otitis media
develops due to chronic inflammation secondary to a perforation in the tympanic membrane
suppurative otitis media presentaion (3)
- copious mucopurulent ear discharge
- hearing loss
- no pain
where is the perforation in tubotympanic otitis media
central perforation of the ear drum - i.e. there is some normal TM on the edge
example of a squamous chronic otitis media
cholesteotoma
cholesteotoma presentaiton (3)
- intermittent foul smelling discharge (may be blood stained)
- hearing loss
- complications icl. facial palsy, vertigo, abscess
what are 6 disease of the inner ear
- labyrinthitis/vestibular neuritis
- menieres disease
- bppv
- vestibular schwannoma
- presbycusis
- noise induced hearing loss
what kind of hearing loss do inner ear problems present with
sensorineural hearing loss
what frequency of sound if lost first is presbycusis
high frequencies
presbycusis mgx
hearing aid
4 ototoxic drug classes
- NSAIDs
- aminoglycosaids
- loop diuretics
- cytotoxic cancer drugs (e.g. platinum)
+ many more
examples of autoimmune conditions that can cause sensorineural hearing loss (4)
- werger’s granulamatosis
- churg - strauss
- SLE
- relapsing polychondritis
what appearance do the semicircular canals have on MRI internal auditory meatus
signet ring appearance
what are the 2 main ear conditions that cause pain
- otitis externa
- otitis media
what is neuropathic otalgia
a diagnosis of exclusion - poorly understood condition where there is a dull ache in the ear that doesn’t respond to simple analgesics and there is no sign of any other ear symptoms (discharge, HL etc.)
neuropathic otalgia mgx
- simple analgesics
- amytriptiline
- gabapentin
what are 6 characteristics of ear discharge to ask about
- mucous
- mucopurulent
- purulent
- bloody
- clear
- foul smelling
