oto disorders of the external ear

Question 1

What are risk factors for development of cerumen

impaction?

Answer 1

Use of cotton-tip applicators, narrow canals, hearing aid
use, earplug or earphone use, hair in the lateral external
auditory canal, developmental delay, advanced age

Question 2

Describe the function(s) of cerumen?

Answer 2

● Cleansing, lubrication, and antimicrobial (bacteria and
fungus) activity
● Lysozyme, saturated fatty acids, and lower pH of ceru-
men provide antifungal and antibacterial properties.

Question 3

What audiometric findings would you expect to

see in a patient with severe cerumen impaction?

Answer 3

● A predominantly high-frequency conductive hearing loss

● Low-volume type B tympanograms

Question 4

Describe the clinical presentation of chondroder-

matitis nodularis chronica helicis.

Answer 4

Intensly painful nodule located on the helix or antihelix that
is commonly pale gray or erythematous

Question 5

What is the appropriate age for repair in patients

with bilateral microtia and congenital aural atresia?

Answer 5

Generally, any repair for microtia or atresia is delayed until
the patient is at least 6 years of age.

Question 6

Review the common sequence of repair during

microtia surgery.

Answer 6

1. Helix formation with rib cartilage
2. Lobule formation
3. Atresiaplasty
4. Formation of the tragus
5. Postauricular release

Question 7

What is the most appropriate initial treatment for

an infant with bilateral congenital aural atresia?

Answer 7

The most appropriate treatment is application of bone-
conduction hearing aids. Providing amplification is crucial for early hearing and language development, although surgical procedures (bone-anchored hearing aid or atresia-
plasty) are generally delayed until the patient is at least 5 years old.

Question 8

What are the indications for surgical treatment of

external auditory canal exostoses?

Answer 8

In patients with chronic or recurrent otitis externa, trapping
of debris, or if a conductive hearing impairment develops,
surgical treatment is indicated.

Question 9

How can exostoses be differentiated from osteomas on clinical examination?

Answer 9

Exostoses are most commonly multiple, medial, and
frequently bilateral, as opposed to osteomas, which exist as
single lesions.

Question 10

Where are osteomas of the ear canal most likely to

develop?

Answer 10

The bony cartilaginous junction

Question 11

Review the indications for otomicroscopic removal
of an ear canal foreign body (as opposed to blind
removal with lavage).

Answer 11

Foreign-body type (e.g., sharp edges, disk battery, vege-
table matter), location adjacent to the tympanic mem-
brane, time > 24 hours in the ear canal, failed previous attempts at removal, in children younger than 4 years

Question 12

What is the most appropriate initial treatment for

patients with severe frostbite of the auricle?

Answer 12

Rapid rewarming of the ear with warm (38 to 42°C) saline-

soaked gauze

Question 13

Describe the examination findings of keratosis

obturans.

Answer 13

Keratosis obturans demonstrates a dense plug of keratin
that completely blocks and may widen the EAC. An
important distinction between keratosus obturans and
canal cholesteatoma is that keratosis obturans involves the
entire circumference of the ear canal while cholesteatoma
often has focal erosion.

Question 14

Describe the treatment for psoriasis of the EAC.

Answer 14

This condition is treated in a similar fashion to psoriasis
elsewhere. First-line treatments include simple warm-water
soaks, application of occlusive ointments (e.g., petrolatum),
avoidance of trauma, and use of topical corticosteroids.
Other specialized topical or systemic treatments (e.g.,
methotrexate, cyclcosporin, retinoids) are generally
reserved for those with extensive disease.

Question 15

What are clinical manifestations of relapsing

polychondritis?

Answer 15

Most common initial symptom is inflammation of the auricle that spares the lobule. Additional organ systems include the joints, nose (nasal chondritis), eyes (conjuncti-
vitis, scleritis, iritis, keratitis), respiratory tract (laryngeal or tracheal inflammation), inner ear, cardiovascular system,
and skin.

Question 16

Describe the appearance of seborrheic dermatitis

of the auricle.

Answer 16

● Inflammatory condition of the skin, generally limited to
oil-rich regions
● It occurs with a wide range of severity, from mild

dandruff and flaking to a generalized exfoliating eryth-
roderma.

● It can be restricted to the ears but more often involves
additional areas such as the scalp, face, upper trunk, and
axillae.

Question 17

Describe the clinical presentation of auricular

tophi.

Answer 17

Moderately painful pink nodules most commonly involving

the helix that contain chalky white material.

Question 18

What is the most commonly cultured organism

from the EAC of patients with otitis externa?

Answer 18

Pseudomonas aeruginosa

Question 19

Why is water exposure a risk factor for acute otitis

externa?

Answer 19

It can lead to loss of the acidic enviroment of the EAC. In

addition, unclean water may carry a high bacterial load.

Question 20

In the presence of a tympanostomy tube or tympanic membrane perforation, how should therapy for acute otitis externa be modified?

Answer 20

Potentially ototoxic medications should be avoided. Specifically, alcoholic and acidic drops should not be used, as well as antibiotics with known cochlear toxicity including aminoglycosides.

Question 21

What is considered first-line therapy for uncomplicated acute otitis externa?

Answer 21

● Pain control, aural toilet, application of ototopical treatments (acidifying/drying agents, antibiotic preparations with or without corticosteroids), and avoidance of risk
factors such as water exposure and ear canal trauma
● Systemic antibiotics are not indicated for uncomplicated
acute otitis externa in an otherwise healthy patient.

Question 22

Describe common initial treatments for fungal

otitis externa.

Answer 22

● Acidifying (aluminum sulfate-calcium acetate) or drying
agents (boric acid)
● Antifungal creams such as clotrimazole may also be used.

Question 23

What treatment may be used for patients with

chronic hypertrophic otitis externa refractory to maximal medical therapy?

Answer 23

Canaloplasty with split-thickness skin graft resurfacing of

the EAC and a generous meatoplasty

Question 24

Describe the clinical features of infectious peri-

chondritis and chondritis of the auricle.

Answer 24

Otalgia and pruritus are the most common symptoms. The
auricle is tender, erythematous, and may have flaking/
weeping over the cartilaginous portions of the auricle with
sparing of the fatty lobule. Risk factors include trauma and
otitis externa.

Question 25

What is the most commonly cultured fungus in

cases of otomycosis?

Answer 25

Aspergillus spp.

Question 26

Define malignant (or necrotizing) otitis externa.

Answer 26

Malignant otitis externa is progressive osteomyelitis of the
temporal bone that has spread from the external auditory
canal. The causative organism is most often Pseudomonas
aeruginosa, and this condition ccurs almost exclusively in

immunocompromised individuals (commonly elderly dia-
betics).

Question 27

What nuclear medicine study is most helpful in
establishing the diagnosis of necrotizing otitis
externa?

Answer 27

Technetium-99 m bone scan detects osteoblastic activity
and is useful for initial diagnosis of osteomyelitis. However,
even after the infection has resolved, the scan remains
positive, making it less useful for monitoring response to
therapy.

Question 28

What nuclear medicine study is most helpful in
evaluating treatment response in patients with
necrotizing otitis externa?

Answer 28

Gallium-67 nuclear medicine scan is useful for detection of
inflammation, although its spatial resolution is poor. It is a
useful adjunct to MRI for the diagnosis of necrotizing otitis
externa. It is also useful in following response to treatment.

Question 29

Describe the mangement of malignant otitis

externa.

Answer 29

Malignant otitis externa is managed primarily with medical
therapy, including 6 + weeks of broad-spectrum antibiotics
(covering Pseudomas spp.), aggressive aural toilet, and strict
glucose control for diabetics. Hyperbaric oxygen therapy is
useful for patients with refractory or advanced disease.
Surgical intervention is reserved for patients with refractory
disease or associated abscess.

Question 30

What is the treatment of bullous myringitis?

Answer 30

● Decompression of painful vesicles, oral pain medication, and systemic antibiotics
● Steroids may be used in cases of sensorineural hearing
loss.