External Otitis At A Glance
acute external otitis?
External otitis or is an infection of the skin
covering the outer ear canal. Acute external otitis is commonly a bacterial
infection caused by streptococcus, staphylococcus, or pseudomonas types
of bacteria. Swimmer’s ear
is a variant of otitis externa usually caused by excessive water exposure.
When water pools in the ear canal (frequently trapped by wax), the skin
will become soggy and serve as an inviting medium for bacteria and
The first sign of infection is
that the ear will feel full and it may itch. Next the ear canal will swell
and ear drainage will follow. At this stage the ear will be very painful,
especially with movement of the outside portion of the ear. The ear canal
can swell shut and the side of the face can become swollen. Next, the glands
of the neck may enlarge, and it can become painful to open the mouth.
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What is chronic
Chronic external otitis can be caused by a bacterial
infection, a skin condition (eczema or seborrhea), fungus (Aspergillosis),
chronic irritation (hearing aids, Q-tips), allergy, chronic drainage from
middle ear disease, tumors (rare), or it may simply follow from a nervous
habit of frequently scratching the ear. In most patients, more than one
factor may be involved. For example, a patient with eczema may subsequently
develop black ear drainage. This would be suggestive of an accompanying
fungus. The standard treatments and preventative measures, as noted below,
are often all that is needed to treat even a chronic otitis externa. However,
in diabetic or immune suppressed individuals, chronic external otitis can
become a serious disease (malignant external otitis). Malignant external
otitis is a misnomer because it is not a tumor or a cancer, but rather an
aggressive bacterial (pseudomonas) infection of the base of the skull.
How do you treat
Regardless of the cause, moisture and irritation
will prolong the course of the problem. For this reason, the ear should
be kept dry. While showering or swimming use an ear plug (one that is designed
to keep water out) or use cotton with Vaseline on the outside.
Scratching the inside of the ear
or using Q-tips should be avoided. This will only aggravate the irritated
skin, and in most situations will make the condition worse. In fact, scratching
the inside of the ear will just make the ear itch more, and any medications
prescribed will be ineffective. A hearing aid should be left out as much
as possible until swelling and discharge stops.
The most common treatment consists
of antibiotic ear drops with or without an oral antibiotic. These
should be used as directed. In some situations, a "wick" will
need to be placed in the ear canal to stent it open and serve as a conduit
for the ear drops. Periodic, and sometimes frequent, suctioning of the ear
canal helps to keep it open, remove debris, and decrease bacterial counts.
How can external
otitis be prevented?
Decrease exposure to water. If you are prone to
infections it is advisable that you use an ear plug when you bathe or
swim. Alcohol drops (Swim Ear) used in the ear after water exposure
followed by drying the ear with a hair dryer held at arms length will
often help keep the ear free of moisture.
not insert instruments, scratch, or use Q-tips in the ears.
Try to keep the ear free of
wax. This may require maintenance type visits to the doctor to have
your ears cleaned, or if your ear will tolerate it, use some of the
over-the-counter wax removers.
If you already have an ear
infection, or if you have a hole in your eardrum, or if you have had
ear surgery or ear
tubes, first consult your doctor prior to swimming and before you
use any type of ear drop.
A preventative ear drop solution
can be cheaply and easily made by mixing equal parts of rubbing alcohol
and white vinegar (50:50 mixture). This solution will increase the rate
of evaporation of water in the ear canal and has antibacterial properties.
Mineral oil ear drops can
be used to protect the ear from water when a dry crusty skin condition
Why do ears itch?
Itchy ears can drive a person crazy. It can
be the first sign of an infection, but if the problem is chronic, it is
more likely caused by a chronic dermatitis of the ear canal. Seborrheic
dermatitis and eczema can both affect the ear canal. There is really no
cure for this problem, but it can be made tolerable with the use of steroid
drops and creams. People with these problems are more prone to acute infectious
exacerbations. Use of ear plugs, alcohol drops, and non-instrumentation
of the ear is the best prevention for infection. Other allergy type treatments
may also help itchy ears.
What if I get
a foreign object or insect in my ear?
Foreign objects are frequently placed in the
ear by young children or
occur accidentally while trying to clean or scratch the ear. Frequently
there is an accompanying external ear infection. Removal of any object from
the ear can be very difficult, and should only be attempted by a physician
skilled in the techniques of safe removal. Usually this can be done in the
office, but sometimes general anesthesia must be used in cases where the
object is lodged too deeply in the ear or if the patient is uncooperative.
It is important to remember that the most common reason an ear is injured
from a foreign object is because of inadvertent damage occurring during
removal of the object.
Insects or bugs may also become
trapped in the ear. Small gnats may become caught in the wax and cannot
fly out. They can
often be washed out with warm water. Larger insects or bugs may not be able
to turn around in the narrow canal. If the insect or bug is still alive,
first kill it by filling the ear with mineral oil. This will suffocate the
insect, then see your doctor to have it removed.
External otitis, or swimmer’s
ear, is an infection of the outer ear canal skin and can occur in acute
and chronic forms.
Excessive water exposure and
frequent instrumentation (usually Q-tips) of the ear canal are important
Itchy ears, a feeling of fullness,
swelling, drainage, and pain are early symptoms.
Antibiotic ear drops and avoidance
of water are frequently necessary for treatment.
Proper ear care can avoid
1. Mild OE
Canal skin may be red with exudate; you may perceive narrowing of the
2. Moderate OE
The canal lumen is narrowed, and can be swollen shut. Skin is
erythematous. Exudate may be present.
3. Complicated OE
The pinna/periauricular soft tissues are erythematous and swollen as
4. Chronic OE
The skin of the canal/pinna is thickened, scaly, and may be erythematous.
Diagnostic Pearl: How to Differentiate Otitis Media from Otitis Externa
Pulling on the pinna (ie: to examine with an otoscope) is extremely
painful in otitis externa, but is usually tolerated in patients with otitis
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Necrotizing (Malignant or Diabetic) Otitis Externa
Key Points in the History:
This is typically associated with elderly diabetics or other
immunocompromised patients. Patients complain of otalgia and otorrhea
persisting more than a month, unresponsive to medical therapy.
Key Physical Signs:
Look for granulation tissue on the floor of the external auditory canal
in the presence of purulent otorrhea. In advanced cases, you'll see cranial
neuropathy, most commonly CN VII, X, or XI.
Key Diagnostic Tests:
CT of temporal bones: shows mastoid clouding, bony destruction
Gallium-67 scan: shows an acute infective focus: will revert to normal
with resolution of infection
Technetium-99 scan: shows osteoblastic activity; will revert to normal
many months after clinical resolution
MRI: monitors cerebral, vascular involvement
Key Therapeutic Options:
As in moderate otitis externa: frequent debridements, topical
antipseudomonal antibiotics, combined with IV antipseudomonals:
Ciprofloxacin, Gentamicin, Tobramycin, etc. Treatment continues for 6 weeks
to 6 months (can switch to oral antibiotics from IV). Diabetic management should be
optimized if applicable. Surgical debridement of necrotic bone is reserved