ENT: Otitis Media & Tonsilitis Flashcards
What is otitis media?
a common infection of the middle ear, that may be bacterial or viral
Who is otitis media predominantly seen in?
Children <4 y/o
What INTRINSIC factors can predispose to otitis media?
1) age <4
2) atopic predisposition
3) immunosuppression
4) conditions affecting ciliary motility:
- CF
- Primary ciliary dyskinesia
- Kartagener’s syndrome
What EXTRINSIC factors can predispose to otitis media?
1) passive smoking
2) not receiving pneumococcal vaccination
3) daycare: the larger the daycare group, the higher the risk.
4) bottle feeding
5) use of a dummy
6) low economic status: poor nutritional status thought to play a role
What vaccine can help protect against otitis media?
Pneumococcal
How can bottle feeding increase the risk of otitis media?
1) The strong swallow required to feed from a breast induces a sizeable negative pressure in the infants oral cavity allowing eustachian tube insufflation. Bottle feeding however, relies more on gravity from the bottle, and less negative pressure is required.
2) Breast milk provides maternal antibodies against common OM pathogens.
What is the middle ear?
The space that sits between the tympanic membrane (ear drum) and the inner ear.
Where does infection come from in otitis media?
The bacteria enter through the back of the throat through the eustachian tube.
What is a bacterial infection of the middle ear often preceded by?
A viral URT infection.
What is the most common bacterial cause of otitis media?
Streptococcus pneumoniae –> this is common cause of other ENT infections such as rhino-sinusitis and tonsilitis.
Give the 4 most common bacteria causing otitis media
1) Strep. pneumoniae
2) Haemophilus influenzae
3) Moraxella catarrhalis
4) Staph. aureus
Pathophysiology in otitis media?
1) OM occurs 2ary to oedema and narrowing of the eustachian tube
2) An oedematous eustachian tube prevents the middle ear from draining –> predisposed to colonoisation
Purpose of the eustachian tube?
The eustachian tube serves to equalise pressure in the middle ear, when the tube is blocked this cannot happen.
Why are children predisposed to OM?
1) their esutachian tubes are narrower and more prone to blockage
2) their eustachian tubes are more horizontal, inhibiting drainage (why the pinna is pulled down for paediatric examination, and up for adults)
3) children have less developed immune systems are are more prone to upper respiratory tract infections (a common cause of eustachian tube oedema)
What can OM be categorised in accordance to?
1) Duration: acute or chronic
2) Effusion: present or absent
What are the 2 types of acute otitis media?
1) Acute otitis media
2) Acute otitis media with effusion
What can acute otitis media with effusion progress to?
Chronic OM with effusion or chronic suppurative
What is the most common cause of hearing impairment in children?
otitis media with effusion.
What are the 2 types of chronic OM?
1) Chronic OM with effusion
2) Chronic suppurative
What is chronic OM with effusion characterised by?
A build up of fluid behind an intact TM.
How long must OM be present for to support a diagnosis of ‘chronic’?
> 3 months
What is chronic OM with effusion also known as?
‘glue ear’
Is acute or chronic OM with effusion more common?
Acute OM
Is acute or chronic OM with effusion more likely to cause hearing impairment?
Chronic
What is chronic suppurative OM?
Presents with persistent ear discharge through a perforated tympanic membrane (TM).
How long must discharge be present for in chronic suppurative OM to support a diagnosis?
> 2 weeks
Clinical features of OM?
1) ear pain/otalgia (most common): may present with ear tugging
2) reduced hearing in affected ear
3) may have symptoms of URT infection e.g. fever, cough, coryzal symptoms, sore throat
4) ear discharge –> if tympanic membrane rupture
5) if infection affects vestibular system –> vertigo, balance issues
How may otitis media present in very young children or infants?
Can be non specific e.g. fever, vomiting, irritability, lethargy, poor feeding.
Otoscopy findings in otitis media?
1) bulging tympanic membrnae –> loss of light reflex
2) opacification or erythema of tympanic membrane
3) perforation with purulent otorrhoea
4) decreased mobility if using pneumatic otoscope
5) if perforation –> may see discharge in the ear canal and a hole in the tympanic membrane.
How to use otoscope in infants <12 months vs >12 months?
<12 months –> gently pull the outer ear down and back.
> 12 months –> pull the outer ear gently up and back
What should the tympanic membrane normally look like?
Pearly grey, transulscent & slightly shiny.
What should you be able to visualise on a normal TM?
1) You should be able to visualise the malleus through the membrane
2) Should be able to visualise a cone of light reflecting the light of the otoscope.
What is it important to exclude in OM?
Systemic infection and serious complications:
1) mastoiditis
2) meningitis
3) intracranial abscess
What investigation is useful as an aid for the diagnosis of middle ear conditions?
Tympanometry
What is involved in tympanometry?
The procedure involves changing the pressure in the outer ear, playing a tone and analysing the reflected sound waves.
The degree of reflection gives a good proxy measurement for the admittance of the TM (the amount of energy transmitted through the TM).
The admittance will be at its maximal point when the pressures on either side of the TM are equal.
What are the 3 most common tympanometry findings?
1) normal waveform: a symmetrical tented ‘teepee-like’ graph is seen.
2) flat waveform
3) similar shaped graph to normal, but the peak is shifted negatively (to the left).
What does a flat waveform finding on tympanometry indicate?
Suggestive of fluid in the middle ear, or rupture of the TM.
What does a waveform similar shaped to normal, but the peak is shifted negatively (to the left)?
This indicates a negative pressure in the middle ear.
What is often the management of acute OM?
Most cases of OM will self resolve without antibiotics and instead use simple analgesia.
When are Abx considered in OM?
A prescription for antibiotics may be given with the advice to take:
a) in 3 days if symptoms do not being to improve
b) or the patient becomes systemically unwell.
Which groups is it recommended to prescribe Abx?
1) Children <2 y/o with bilateral OM
2) Children <3 months with a temp >38
3) OM with ear discharge (otorrhoea)
4) Systemically unwell
5) High risk of complications or immunosuppressed
1st line Abx in OM?
1st –> amoxicillin (5-7 day course)
2nd –> erythromycin or clarithromycin
When should admission be considered in OM?
Consider admission in infants younger than 3 months with a temperature above 38ºC or 3 – 6 months with a temperature higher than 39ºC.
What are the three options regarding prescribing antibiotics to patients with otitis media?
1) immediate Abx
2) delayed Abx
3) no Abx
Management of acute and chronic otitis media with effusion (glue ear)?
1) Conservative management & observation for 6-12 weeks
2) Pure tone audiometry
3) Referral to 2ary care if:
- There is concern with the child’s development
- The hearing loss persists after other symptoms have resolved
- There is severe hearing loss
- The child has Down’s syndrome or cleft palate
What 2 congenital abnormalities would you refer to 2ary care in chronic OM with glue ear?
1) Down’s syndrome
2) Cleft palate
Management options in 2ary care of chronic otitis media with effusion (glue ear)?
1) hearing aids –> offered to patients with persistent bilateral symptoms
2) Eustachian tube autoinflation –> blowing up a balloon with the nostrils several times a day
3) Surgical –> myringotomy with grommet insertion
What is a grommet?
A grommet is a tube, surgically inserted in the TM, that allows middle ear ventilation and the drainage of excess secretions.
How long are grommets usually in for?
They are ordinarily a temporary measure lasting around 12 months.
What are some complications of OM?
Common:
1) Chronic OM (8% will progress)
2) Tympanic membrane perforation
3) Hearing loss (more common with recurrent OM)
4) Tinnitus
Uncommon:
1) Mastoiditis
2) Bacterial meningitis
3) Extradural abscess
4) Subdural abscess
5) Labyrinthitis
6) Facial paralysis
What advice is given in TM perforation in acute OM?
This is a common occurrence and will ordinarily heal within a few weeks
1) avoid swimming
2) be careful in shower
3) assess site –> monitor for mastoiditis
Perforations in what area of TM are more likely to lead to mastoiditis?
Upper portion of drum
What is mastoiditis?
Mastoiditis is inflammation of the mastoid antrum and the lining of the mastoid air cells.
What is the mastoid process?
The area of bone formed of the petrous temporal and occipital bones which is present posterior and inferior to the external auditory meatus.
What is mastoiditis usually the result of?
Infection of the middle ear –> OM
It most commonly occurs in children of school age following an UNTREATED episode of acute otitis media or after RECURRENT episodes of otitis media.
What are the most common pathogen causing OM/mastoiditis in young children prior to vaccination?
Haemophilus influenzae
What are the most common pathogen causing OM/mastoiditis in children of school age?
Strep. pneumoniae (& strep. pyogenes)