Chapter 37 - Ear Infections

Question 1

Essentials to Dx AOM

Answer 1

moderate to severe bulging TM or new otorrhea not associated with OE
Mild bulging of TM and <48hr otalgia or erythema of TM
Middle ear effusion must be present (pneumatic otoscopy or tympanometry)

Question 2

Diagnosis of AOE

Answer 2

rapid onset (<48 hr) of Sx (pain OOP to exam, exacerbate with palpation of tragus, pinna)
ear canal inflammation (erythema, edema, drain)
Other sx: plugged feeling, EAC swelling, debris

Question 3

Bugs causing AOM

Answer 3

S Pneumo (35-40%), H Flu (30-35%), Moraxella (15-20%)

Question 4

Percentage of AOM bacteria susceptible to amoxicillin

Answer 4

80%

Question 5

Pathogenesis of OE

Answer 5

disruption of protective mechanisms
Remove cerumen, traumatize ear canal with q tip, fingernail, ear plugs, or foreign body
Moist, humid environment also weakens skin barriers
98% of AOE is bacterial

Question 6

Function of cerumen

Answer 6

bacteriostatic
slightly acidic (also aids in inhibiting infection)
barrier to moisture

Question 7

2 most common OE bugs

Answer 7

S Aureus, Pseudomonas

Question 8

How to protect yourself from getting OE

Answer 8

acidifying ear drops
prevent water exposure to EAC
remove obstructing cerumen (by an ENT)
dry ear canal with hair dryer (cool setting)
avoid direct ear canal trauma

Question 9

What causes eczema of the EAC with OE?

Answer 9

drainage

Question 10

Chronic Otitis Externa: definition

Answer 10

otorrhea with sx of OE
>6 wk
May occur after inadequate treatment of OE

Question 11

Malignant Otitis Externa: patient, complications, sx

Answer 11

Infection of skull base may be after acute or chronic OE
Elderly, DM, Immunocomp
May spread intracranially
Deep stabbing ear pain worse with head motion, otorrhea, fever, loss of voice, dysphagia, facial weak

Question 12

Complications of OE

Answer 12

MOE
facial cellulitis
irritation of skin of ear/neck

Question 13

Treatment of OE

Answer 13

debride the debris, restore normal pH, topical antimicrobial, remove causative agent

Fluoroquinolone drops
Systemic if systemic sx present or spread outside ear canal

Question 14

Drops for pre/post swimming in pt with recurrent OE

Answer 14

2-3 drops of 1:1 solution white vinegar and 70% ethyl alcohol

Question 15

Bullous myringitis: bugs, hearing changes

Answer 15

virus, S Pneumo, Staph

May cause CHL

Question 16

Tx bullous myringitis

Answer 16

If viral- analgesic, antiinflamm

If signs of bacterial- topic or oral ABx

Question 17

Risk factors for otitis media

Answer 17

younger patient
colonization of NP with otitis pathogens
URI
smoke exposure
bottle feeding
time of year/daycare attendance
genetics

Question 18

Bony vs Cartilage eustachian tube

Answer 18

Bony 1/3 nearest to middle ear
Cartilaginous 2/3 closer to nasopharynx
(opposite of EAC, where 1/3 cartilage, 2/3 bony)

Question 19

Muscles associated with ET

Answer 19

salpingopharyngeus, TT, TVP, LVP

Question 20

How otitis media occurs

Answer 20

middle ear under constant negative pressure

When ET is dysfunctional, its unable to equalize the pressure, so fluid builds up, gets infected

Question 21

Eustachian tube in children

Answer 21

flat, less rigid, shorter

Question 22

2 most common mastoiditis pathogens

Answer 22

S Aureus, S Pyogenes

Question 23

What is a biofilm?

Answer 23

groups of bacteria residing in extracellular matrix
matrix resistant to ABX penetration
bacteria share resistance genes and defense mechanisms
In middle ear and nasopharynx, shed plaktonic bacteria, induce inflammation

Question 24

When to use augmentin for AOM

Answer 24

failed amoxicillin after 48-72 hr
has had amoxicillin in last 30 d
otitis conjunctivitis syndrome (more likely non-type H Flu)

Question 25

Meds other than amoxil/augmentin for AOM

Answer 25

Ceph - if penicillin sensitive not severe
Bactrim, Clinda, Macrolide - if severe penicillin sensitive
IM Ceftriaxone- fail oral therapy

Question 26

Which patients can you decide to not use ABX for with AOM?

Answer 26

Over 6 mo, may observe 2-3d if minimal sx, “wait and see”

Question 27

How bottle feeding can lead to ear infections

Answer 27

If baby lying flat and you prop the bottle –> fluid can enter the eustachian tube
vacuum (neg pressure) created by sucking bottle can transmit to middle ear (doesn’t happen with breast feed)

Question 28

Dosing of drugs for AOM: Amoxicillin, Augmentin, Cefdinir, Cefuroxime, Cefpodoxime, Ceftriaxone, Clinda

Answer 28

Amoxil- 80-90mg/kg/day BID
Augmentin- 90mg/kg/d
Cefdinir- 14mg/kg/day 1-2 doses
Cefuroxime- 30mg/kg/d BID
Cefpodoxime- 10mg/kg/d ID
Ceftriaxone- 50mg IM or IV per day 1-3d
Clinday 30-40mg/kg/d, TID

Question 29

Treatment after initial AOM ABx fail (2-3d)

Answer 29

Augmentin
Ceftriaxone

Or: Clinda, tympanocentesis

Question 30

How long can OME persist after AOM?

Answer 30

3-6 mo (90% resolve by 3mo)

Question 31

Per one study, does pacifier use increase or decrease AOM risk?

Answer 31

Decrease

Question 32

Which additional illness combined with AOM episodes would warrant an immune evaluation

Answer 32

pneumonia

Question 33

When to test hearing in OME

Answer 33

when lasts >3mo

earlier if risks of language delay

Question 34

How long to ear tubes last? What pushes them out?

Answer 34

on average, 6-12mo

desquamation of epithelial layer of TM

Question 35

What is CSOM (chronic suppurative otitis media)? How do you treat?

Answer 35

inflammation of mastoid and middle ear for at least 6wk
may be due to cholesteatoma, perforated TM, ventilation tubes
topical drops - ofloxacin, dry ear precautions, address allergy/adenoids