Ear, Nose and Throat Flashcards
What is otitis externa and its most likely causative organisms?
Infection of the outer ear, external auditory meatus etc
Normally caused by pseudomonas aeurginosa or staphylococcus aureus
Can be acute (less than 3 months) or chronic (more than 3 months)
What can precipitate otitis externa?
Ear trauma
Excessive moisture e.g. swimming for a long time
Dermatitis
Hearing aids
Narrower canal
How does otitis externa normally present?
Otalgia + can refer + pinna and tragus tenderness
Otorrhoea - creamy and nasty smelling
Itching
Feeling of fullness
Onset over about 48 hours
How does the ear canal look in otitis externa?
Erythematous
Mild = normal diameter, mod = reduced diameter, severe = occluded
Creamy discharge
How does the tympanic membrane look in otitis externa?
In tact
Might not be able to see
What is the management for otitis externa?
Conservative - don’t get wet - ear plugs and tight swimming cap, blow dry on a low heat, can still fly
Medical - topic abx/anti-fungals +/- steroids
use empirical ones
Microsuction
Can wick if need to and will open up the canal over days
Swab if treatment resistant
What are the complications of otitis externa?
Malignant/necrotising otitis externa
Infection invades adjacent cartilage and bone leading to temporal bone destruction and osteomyelitis at the base of the skull
More common if immunosuppressed or an insulin dependant diabetic
Can also get a facial nerve palsy
Need IV abx in addition to topical
What is cauliflower ear?
A haematoma of the perichondrium within the pinna
How is cauliflower ear managed? What are the complications?
Drainage
Abx
Wear a scrum cap or something (this is a bad card)
What are the symptoms of a tympanic membrane perforation?
PAIN
? conductive hearing loss
What is the management of a tympanic membrane perforation?
Manage conservatively - watch and wait as should heal itself and keep dry
Doesn’t heal after 6 months = myringoplasty (repair it)
Why can the middle ear be counted as a continuation of the upper respiratory tract? Why is this significant?
Has the same epithelium (pseudostratified columnar)
Means they’re susceptible to the same organisms e.g. strep pneumoniae, h influenzae etc
Dysfunction of which structure is acute otitis media associated with?
Eustachian tube dysfunction
muffled hearing, pain, tinnitus, reduced hearing, a feeling of fullness in the ear or problems with balance may occur.
What are the risk factors for acute otitis media?
non-modifiable = More common in 1-4 year olds, craniofacial abnormality e.g. cleft palate
modifiable = passive smoking, nursery, formula feeding
How does acute otitis media normally present?
Rapid onset otalgia (often ear pulling in children)
Mucousy discharge from the ear
Fever +/- irritability
Often following a URTI
How will the tympanic membrane look in acute otitis media?
Erythematous
Bulging of the pars flaccida
Dilated vessels
What are the intracranial complications of acute otitis media?
Intracranial abscess
Meningitis
Sinus thrombosis
How should acute otitis media be managed?
Analgesia
Amoxicillin PO or Clarithromycin PO
What are the intra-temporal bone complications of acute otitis media?
Mastoiditis
Facial Nerve paralysis
What are the complications of acute otitis media relating to the ear?
Recurrence/ persistence with effusion
Labrynthitis
TM perforation
Conductive hearing loss (temporary)
Describe the intracranial route of the facial nerve
Arises from the pons
Internal acoustic meatus
Petrous part of temporal bone
Facial canal
Forms the geniculate ganglion then gives rise to 3 nerves: greater petrosal nerve, nerve to stapedius and Chordae tympani
Exits via the stylomastoid foramen
What is the function of the greater petrosal nerve? What happens if there’s a lesion
Parasympathetic fibres to mucous glands and lacrimal gland
Reduced tear production on ipsilateral side
What is the function of the nerve to stapedius? What happens if there’s a lesion?
Motor fibres to stapedius muscle of the middle ear
Lesion = ipsilateral hyperacusis
What is the function the chordae tympani? What happens if there’s a lesion?
Special sensory fibres to the anterior 2/3 tongue
Parasympathetic fibres to the submandibular and sublingual glands
Lesion = Dry mouth and loss of taste on the ipsilateral 2/3 of the tongue
Describe the extra cranial route of the facial nerve
Travels anteriorly to outer ear
Then through the parotid gland (but doesn’t innervate) where it splits into 5 branches (To Zanzibar By Motor Car)
Temporal Zygomatic Buccal Marginal Mandibular Cervical
What are the 5 branches of the facial nerve?
To Zanzibar By Motor Car!
Temporal Zygomatic Buccal Marginal mandibular Cervical
They innervate muscles of facial expression
How does otitis media with effusion differ to otitis media?
OME = fluid within the middle ear leading to Eustachian tube dysfunction and the tympanic membrane is still in tact
Most commonly presents with HEARING LOSS and no signs of acute inflammation (no pain)
Leads to conductive hearing loss (and ?developmental delay)
How does the tympanic membrane look on examination in OME?
Abnormal colour of the drum e.g. yellow
Loss of light reflex
More opaque
Air bubbles
Retracted or concave
What are the risk factors for developing OME?
Non-modifiable = congenital abnormalities e.g. down’s, CF, cleft palate
Modifiable = low socioeconomic group, parental smoking, frequent URTIs
What are the investigations to diagnose OME?
Tympanogram - Flat tracing with normal canal volume
Pure tone audiogram - Conductive hearing loss