Australian Doctor Australian Doctor 30th June 2017 | Page 22

How to Treat – Conditions of the external ear
Figure 7. Three
broad-based bony
growths/exostoses
of the external
auditory canal.
from page 19
should be provided in the form
of paracetamol, NSAIDs and a
limited prescription (two to three-
day supply) of opioids if the pain
is severe. Advise patients to take
paracetamol and NSAIDs on a
regular basis if the pain is severe
enough to require additional opi-
oids. Warn the patient they should
return for re-assessment if the pain
does not subside, or worsens after
2-3 days of therapy. If there is no
contraindication, oral steroids
may also help.
Aural toilet should be per-
formed to reduce the gross debris
and discharge from the external
auditory canal to allow topical
drops to penetrate the infected
tissue. This can be performed by
a specialist using a microscope or
similar device. Lavage should not
be attempted if there is a history
of immunosuppression, as this
can potentially precipitate skull
base osteomyelitis. These patients
should be reviewed by a special-
ist for removal of debris with a
microscope.
Practitioners and patients (or
carers) can also use tissue spears (a
loosely rolled-up corner of a soft
piece of facial tissue) to help gently
clear any obvious physical debris
from the ear canal.
If the canal is swollen suffi-
ciently that visualisation of the
tympanic membrane is difficult, an
ear wick can be used to facilitate
topical drug delivery. Pre-made
wicks are commercially available
for use in otitis externa. These
expand when exposed to mois-
ture, facilitating delivery of medi-
cation as well as reducing canal
oedema. Any patient who has a
wick inserted should be reviewed
within 4-5 days to ensure the wick
is removed or has fallen out once
canal swelling has improved. If the
clinician is unfamiliar with using
ear wicks or is concerned about
canal swelling, an early specialist
referral is indicated.
Several studies and guidelines
recommend the use of topical anti-
microbial agents as initial therapy
for uncomplicated acute otitis
externa. 10,11 These agents have been
shown to improve oedema, itch,
erythema, discharge and pain as
soon as three days after therapy is
started. 10, 11 The advantage of topi-
cal therapy is that a very high con-
centration of antimicrobials can be
delivered to the ear canal, between
100–1000 times the concentration
of systemic therapy. This is impor-
tant as it is extremely efficacious
– even against organisms that have
shown antimicrobial resistance
– as minimum inhibitory concen-
trations are calculated based on
systemic dosing .10
The choice of topical agents
requires good activity against P.
aeruginosa and Staphylococcus
spp – there is good evidence for the
use and safety of topical quinolone
agents (ciprofloxacin ear drops —
three drops to affected ear, three
times a day) 10, 11
The eTherapuetic Guidelines
(March 2017) states: “Instil com-
bination corticosteroid and anti-
biotic ear drops after performing
aural toilet; use:
• 
dexamethasone + framycetin
+ gramicidin 0.05% + 0.5% +
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| Australian Doctor | 30 June 2017
Viral infections of external ear
Viral infections of the external ear
are rare. Common viruses impli-
cated are varicella, measles or
herpes virus. Herpes zoster infec-
tion, also known as shingles, of the
geniculate ganglion of the facial
nerve (part of the facial nerve
which resides in the inner ear)
results in Ramsay Hunt syndrome.
This syndrome presents with a
vesicular eruption in the external
ear canal and posterior pinna with
severe pain, facial nerve palsy, loss
of taste and reduced tearing on the
affected side. Unfortunately, the
prognosis of facial nerve recovery
is not as good as it is in idiopathic
facial nerve palsy (Bell’s palsy).
Management consists of prompt
administration of systemic antivi-
ral therapy (such as valaciclovir or
famciclovir) and systemic steroids.
Skull base osteomyelitis
Box 5. When to refer a patient with symptomatic cerumen impaction to
a specialist for manual removal (irrigation is contraindicated in these
situations):
• A perforated tympanic membrane or patent tympanostomy tube
• A history of prior ear surgery – especially surgery on the mastoid
• A history of radiotherapy around the ear – both current radiotherapy or
previous history of radiotherapy
• Individuals with skin conditions affecting the external auditory canal
• Individuals with anatomically narrow ear canals – exostoses, aural atresia,
canal stenosis
• Immunodeficiency – this is not a contraindication to irrigation but the
clinician must be cautious of patients who get recurrent otitis externa
– Conditions such as diabetes mellitus, HIV or patients taking
immunosuppressive medications
FUNGAL OTITIS
EXTERNA HAS THE
POTENTIAL TO
CAUSE SKULL BASE
OSTEOMYELITIS IN
INDIVIDUALS WHO ARE
IMMUNOCOMPROMISED .
0.005% ear drops three drops,
instilled into the affected ear, three
times daily for 3-7 days;
OR
• 
flumethasone
+
clioquinol
0.02% + 1% ear drops, three
drops instilled into the affected
ear, twice daily for 3-7 days.”
Combination antimicrobial and
steroid drops are available (cip-
rofloxacin + dexamethasone) and
can be considered in cases where
canal swelling is severe.
Patients should be counselled
on the administration of ear drops
to ensure adequate delivery — see
box 3.
Systemic antibiotics are not rec-
ommended in the initial therapy
of uncomplicated acute otitis
externa. 10, 11 They do not penetrate
tissues at the same concentrations
as topical therapy and high-quality
research has shown no benefits in
their use in this setting. Systemic
therapy can contribute to resist-
ance and lead to side effects such
as rashes, vomiting, diarrhoea,
allergic reactions and fungal infec-
tions. 10 Despite this recommen-
dation, systemic therapy is often
unnecessarily used as initial treat-
ment in otitis externa. 5, 6 The sce-
narios requiring both topical and
systemic antibiotic therapy are
listed in box 4.
Provide patients with strategies
to minimise further trauma to the
ear canal. The use of a cotton ball
covered in petroleum jelly in the
meatus prior to showering can
prevent further moisture entering
the external auditory canal. Advise
patients to avoid swimming for at
least 1-2 weeks during treatment.
If the ear canal does get wet, it can
be dried using tissue spears or a
hair dryer on the lowest heat set-
ting.
Patients should avoid using
hearing aids, earphones or ear
muffs while there is pain or dis-
charge. Once the infection settles
and the patient wishes to reuse
these devices, they should be wiped
down with alcohol wipes prior to
reinsertion into the ear canal.
Furuncle
A furuncle is a localised collection
of pus in the external auditory
canal, arising from the hair folli-
cles in the outer third of the canal.
Fur uncles occur more commonly
in immunosuppressed individuals
and S. aureus is the most frequent
causative organism. 9 These present
similarly to otitis externa but on
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clinical examination, the swelling
involving the ear canal is localised
and not diffuse (as it is in acute
otitis externa). It is possible for
these collections to spontaneously
rupture and present with purulent
discharge.
Therapy consists of sympto-
matic relief with analgesia, warm
compresses to the area and topical
antibiotic ointment in addition to
anti-staphylococcal oral antibiot-
ics (dicloxacillin or flucloxacil-
lin). If the lesion is fluctuant and
direct visualisation is possible,
incision and drainage can be per-
formed under local anaesthesia
(with topical agents). If there are
any difficulties in managing these
patients, seek specialist advice to
prevent deterioration and spread
of disease.
Fungal otitis externa
Fungal otitis externa, also known
as otomycosis, is a uncommon
cause of otitis externa, accounting
for less than 5% of all cases. 9 It can
be associated with systemic or top-
ical antibiotic therapy. In contrast
to bacterial otitis externa, patients
with otomycosis present predomi-
nantly with pruritis and clear dis-
charge. Patients with otomycosis
typically don’t have the pain or
swelling that is associated with
acute otitis externa. On examina-
tion, patients have characteristic
debris in the external auditory
canal; candida infections result in a
white ’cotton-like’ debris whereas
aspergillus infections result in a
‘wet newspaper’ appearance with
moist white debris spotted with
black dots. 9
Otomycosis is a clinical diagno-
sis, however fungal cultures are
recommended in patients prior
to instilling treatment. Treatment
consists of aural toilet to remove
the superficial fungal hyphae and
dead skin, followed by the appli-
cation of topical antifungal ear
drops (either flumethasone + clio-
quinol, or triamcinolone + neo-
mycin + gramicidin + nystatin ear
drops). If patients fail to respond,
consider specialist referral or fur-
ther removal of debris with oral
antifungals in treatment-resistant
cases. Fungal otitis externa has
the potential to cause skull base
osteomyelitis in individuals who
are immunocompromised. Early
referral is suggested in these cases.
Skull base osteomyelitis, also
known as malignant or necrotising
otitis externa, is a life-threatening
condition that should always be
considered and excluded when
assessing a patient with severe
otalgia. It is a progressive infection
of the external auditory canal that
invades the skull base. It is thought
to originate from the bony-carti-
laginous junction of the external
auditory canal where there are fis-
sures allowing infection to spread
medially to the skull base (fissures
of Santorini).
Elderly patients and people with
diabetes are the most commonly
affected, as microvascular disease
is thought to predispose to this
process of invasion. The offend-
ing organisms invade into blood
vessels, resulting in vasculitis and
coagulative necrosis of surround-
ing tissue.
There are three parameters that
aid in the diagnosis of malignant
otitis externa: clinical findings of
granulation tissue (in the form
of a polyp) or exposed bone in
the floor of the external auditory
canal, markedly raised ESR or
CRP and radiographic evidence of
abnormal soft tissue in the exter-
nal auditory canal and skull base. 12
Patients with skull base osteo-
myelitis have often failed attempts
at managing acute otitis externa,
and their symptoms persist.
The symptoms are the same as
acute bacterial otitis externa, as
described above. However, the
pain is described as a “deep” and
“excruciating” pain felt in the ear,
often worse at night. As the disease
progresses, it can involve the facial
nerve in addition to the hypoglos-
sal and accessory nerves. Patients
who have any of the above features
should be immediately referred to
the ED for further assessment and
management.
Approximately 90% of skull
base osteomyelitis is caused by P.
aeruginosa. Treatment consists of
parenteral antibiotic therapy for a
considerable length of time in the
hospital setting and in the commu-
nity, with frequent follow-up and
imaging to monitor progress. 12
Dermatological conditions of
external ear
Primary dermatological conditions
such as eczema, psoriasis and seb-
orrhoeic dermatitis are common