AOM

Question 1

What is the pathophysiology of AOM?

Answer 1

Eustachian tube dysfunction or obstruction due to mucosal inflammation (viral infection) impairs mucocilliary clearance mechanisms that ventilate and drain the middle ear.
The lack of middle ear drainage leads to fluid stasis and bacterial colonisation –> AOM

Question 2

Why do kids get more AOM?

Answer 2

More viral infection
Shorter eustachian tubes
More horizontal eustachian tubes

Question 3

What are some risk factors for AOM?

Answer 3

Young age
Contact with other children - increased exposure to viral infections
Orofacial abnormalities
Household crowding
Cigarette smoke 
Pacifier use
Shorter duration of breastfeeding
Prolonged bottle feeding while lying down
Family history
First Nations and Inuit
Low IgA

Question 4

What are the bacterial pathogens for AOM?

Answer 4

High virulence: Step pneumonia and strep progenies

Low virulence: moraxella catarrhalis and other strains of hemophilus influenza

Question 5

Does vaccination prevent AOM?

Answer 5

Yes. After uptake of PCV7 and now PCV13 - decrease in the incidence of AOM
PCV 13 - decrease in nasopharyngeal colonization

Question 6

Why is it important to distinguish which children TRULY have AOM and which do not?

Answer 6

Giving too many antibiotics: side effects and increase colonisation of resistant organisms
Giving too few antibiotics: if you do not get rid of the bacteria colonised that have cause AOM, then you get relapses

Question 7

How do you make the diagnosis of AOM?

Answer 7

1. Presence of effusion: you can see this with a pneumatic otoscope, also loss of bony landmarks and air/fluid levels. NB automated tympanometry is unreliable in kids
2. Inflammation: red or opaque, bulging or retracted
3. Acute symptoms

Question 8

Does perforation happen in both viral and bacterial causes?

Answer 8

TM perforation strongly supports a bacterial cause

NB this should be distinguished from AOE with pre perforation

Question 9

What are some complications of AOM?

Answer 9

Mastoiditis
VII palsy
Gradenigo’s syndrome - VI palsy associated with apterous bone inflammation or infection
Labarynthitis - spread of infection to the cochlear cells
Sinus enosis thrombosis (of the transverse, lateral or sigmoid sinus)
Meningitis

Question 10

Are there any situations when you treat a kid with antibiotics without risk stratifying?

Answer 10

Perforated TM

Question 11

Which kids should get watchful waiting?

Answer 11

Mild - moderte bulging

Low grade fever

Question 12

How long do you watchful wait for?

Answer 12

24 - 48 hours

Question 13

What is the first line antibiotic?

Why? (2)

Answer 13

Amoxicillin - these doses ensure amoxicillin is at good levels for 50% of the day
75-90mg/kg BID
45-60 mg/kg TID
Why: good middle ear penetration and pathogens (Step pneumo and GAS are susceptible)

Question 14

If the kid doesn’t improve on amoxicillin what should you check and what should you do?

Answer 14

Check compliance

If compliance is good change to Amox-clav to cover moraxella and H influenza resistance

Question 15

What are the two situations when you should consider a different first line antibiotic?
What antibiotic would you choose?

Answer 15

1. if there is conjunctivitis-otitis syndrome, caused by H influenza and Moraxella
2. If the child had antibiotics for AOM in the last 30 days

Both of these situation you would choose Amox-clav

Question 16

How long should you treat for

Answer 16

> 2 - 5 days

Question 17

What do you do in the face of diagnostic uncertainty?

Answer 17

Ensure that you have thought about all the possible differential diagnoses.
If the child is mildly ill and feeding well and has reliable caregivers - watch and wait

Question 18

What type of resistance can H Influenza and Moraxella have?

Answer 18

Beta lactase producing.

Question 19

What do you use if the child is penicillin allergic

Answer 19

2nd (cefpozil and cefuroxime) or 3rd generation (ceftriaxone x 3 days) cephalosporin
Macrolide or clindamycin - although less effective killing os strep pneumo