Otitis media and externa Flashcards
Define mastoiditis.
Mastoiditis typically develops when an infection spreads from the middle to the mastoid air spaces of the temporal bone.
What is the aetiology of mastoiditis?
Bacterial otitis media extends into the mastoid air cells that are contiguous with the middle ear
What are the clinical features of mastoiditis?
- otalgia: severe, classically behind the ear
- there may be a history of recurrent otitis media
- fever
- the patient is typically very unwell
- swelling, erythema and tenderness over the mastoid process
- the external ear may protrude forwards
- ear discharge may be present if the eardrum has perforated
How is mastoiditis diagnosed?
Clinical features although CT can be done if complications suspected
e.g. pain on palpation of the mastoid bone and bulging of the affected ear due to swelling along with symptoms of otitis media.
How is mastoiditis managed?
Urgent referral to hospital
IV antibiotics - should respond well
If severe:
Cortical mastoidectomy if subperiosteal abscess - aim to drain mastoid antrum and air cells without touching middle ear, ossicles or external meatus.
A post-aural incision - exposes the mastoid process bone and the cortex is removed by drilling.
What are the complications of mastoiditis?
- CNVII palsy
- Hearing loss
- Meningitis
- Extradural abscess
What happens if mastoiditis is left untreated?
Abscess may discharge posterior to the pinna and cause a fistula permanently.
Can alternatively cause a SCM abscess and discharge there.
Also can cause intractanial complications.
What is seen on XR of mastoid in mastoiditis?
opacity and air coalescence
What is the treatment for otitis externa in a patient with diabetes?
Ciprofloxacin to cover for Pseudomonas
Name the structures on this diagram.
Lateral process of the malleus shows that this is the right ear as they always point anteriorly
Pars tensa = stiff bit, Pars flaccida = floppy bit
What type of cells is the tympanic membrane made up of?
Outermost = stratified squamous epithelium
Innermost = part of respiratory system, pseudostratified ciliated columnar epithelium
What is the anterior recess of the ear?
Part between the tympanic mebrane and the TMJ in the ear canal where any fluid may collect
What is the function of the eustachian tube?
Supplies middle ear with fresh air
What pathogens cause otitis externa?
Usually skin commensals
Staph
Other:
* Klebsiella
* E coli
* Pseudomonas
What is the management of otitis externa?
Topical antibiotic +/- combined with a steroid
- NB: if the tympanic membrane is perforated aminoglycosides are traditionally not used. Give oral flucloxacillin if the infection is spreading
Removal of debris - if there is canal debris then consider removal
Ear wick insertion - if the canal is extensively swollen
What is the problem with using aminoglycosides for otitis externa?
Ototoxicity - worst if tympanic membrane is perforated (which will be hard to judge due to swelling)
SO do not give unless sure. Instead use e.g.ciprofloxacin/dexamethasone
What is shown?
Complication of untreated otitis externa - needs admission for IV abx
Probably caused by Strep rather than Staph.
Worst complication: osteomyelitis of the skull
What are the causes of otitis externa?
infection: bacterial (Staphylococcus aureus, Pseudomonas aeruginosa) or fungal
seborrhoeic dermatitis
contact dermatitis (allergic and irritant)
recent swimming is a common trigger of otitis externa
What type of otitis externa is this?
Fungal
What are the clinical features of otitis externa?
- ear pain, itch, discharge
- otoscopy: red, swollen, or eczematous canal
What is shown?
Otitis media - infection is behind the tympanic membrane
NB: injected membrane, yellowish colour is pus (abscess inside)
List the criteria needed to diagnose otitis media.
- Acute onset pain
- Presentce of middle ear effusion - bulging or otorrhoea or decreased mobility on pneumatic otoscopy
- Inflammation of membrane
What are the main complications of otitis media?
Mastoiditis - if infection spreads posteriorly
Tympanic membrane perforation (shown) - due to increased pressure from fluid.
Brain abscess
Meningitis
What are the main clinical features of otitis media?
Otalgia
Fever in 50%
Hearing loss
Recent URTI symptoms
Ear discharge if tympanic membrane perforates
Pain first, then discharge and less pain
O/E:
Bulging tympanic membrane -> loss of light reflex
Opacification/erythema of membrane
Perforation with purulent otorrhoea
What is the management of otitis media?
USUALLY SELF LIMITING - and does NOT require antibiotic prescriptions
Analgesia
+/- Amoxicillin 5-7 days - if pen allergic then erythro/clarithromycin
Antibiotics should be prescribed immediately if:
Symptoms lasting more than 4 days
Systemically unwell
Immunocompromise or high risk of complications
< 2 years old with bilateral otitis media
Otitis media with perforation and/or discharge in the canal
What is shown on right?
Right membrane is retracted, yellow discolouration, thinned membrane = otitis media with effusion (“glue ear”)
What is the aetiology of otitis media?
Usually begins as viral URTI which disrupts normal nasopharyngeal microbiome allowing bacteria to infect eustachian tube and middle ear
Most OM is secondary to bacteria e.g. S. pneumoniae, H. influenzae, M. catarrhalis
What are the common sequelae after perforation in otitis media?
CSOM - chronic suppurative otitis media if perforation and otorrhoea lasts >6week
hearing loss
labyrinthitis
What is malignant otitis externa?
Otitis externa in immunocompromised individuals (90% in diabetics) usually caused by Pseudomonas and progressing to involve the soft tissues into the eat canal and eventually to temporal bone osteomyelitis
What are some clinical features of malignant otitis externa?
Diabetes (90%) or immunosuppression (illness or treatment-related)
Severe, unrelenting, deep-seated otalgia
Temporal headaches
Purulent otorrhea
Possibly dysphagia, hoarseness, and/or facial nerve dysfunction
How do you diagnose malignant otitis externa?
CT
What is the management of malignant otitis externa?
Urgent referral to ENT
IV antibiotics to cover pseudomonas
