Ï.ÍÓíä ÌÇÓã L.2 Diseases of the external ear
A. Diseases of the auricle:The diseases or abnormalities that affect the auricle are divided
into:
a. .Congenital b. traumatic c. inflammatory d. neoplastic diseases.
a. .Congenital diseases:
1. .Anotia: it’s a complete absence of the auricle, it occurs due to acongenital defect in the auricle patches.
2. .Microtia: the auricle is smaller than normal.
3. .Bat ear:
4. .Accessory auricles:
These defects could be unilateral (common) or bilateral (rare). If the
condition is unilateral it does not require treatment, but in bilateral
(conductive deafness) cases & the patient is below (8 yr.) the defect should be
corrected by hearing aids at first & then by surgery, because the patient cannot
learn to speak after this age. The other indication for surgery is cosmetic.
b. .Traumatic diseases:
1. .Hematoma:
It’s the most common traumatic condition of the auricle resulting
from close injury to the auricle like a blow or any blunt injury (not
laceration). Then the blood will accumulate under the skin of the auricle &
above the cartilage & a gradual swelling appear which have a reddish blue color
in the affected area.
Clinical features:
- -Painful swelling under the skin.
- -Conductive deafness if the swelling is near the EAC.
- -Necrosis of the cartilage of the pinna, which end with fibrosis & deformity,
called cowliflower deformity.
- -Perichondritis which is inflammation of the perichondrium.
Treatment:
Urgent evacuation of the hematoma & pressure dressing with heavy antibiotics
to control the infection & prevent reaccumulation.
2. Laceration of the auricle:
Usually caused by crush injury leading to laceration of the auricle,
it’s treated by excision of the affected area repair of the edges together.
c. .Inflammatory diseases:
Perichondritis:
It means inflammation of the perichondrium of any cartilage in the body
e.g.(larynx, nasal septum).
Etiology:
1- -Septic surgery.
2- -Hematoma.
3- -Trauma.
4- -Insect bite.
Organism: G+ve bacteria, occasionally G-ve bacteria specially pseudomonas.
Clinical features:
1- -Painful swelling, redness, tenderness of the auricle except the lobule of
the auricle.
2- -It’s a self-limited disease, but it may be complicated by abscess
formation, which require urgent drainage.
Treatment: of uncomplicated cases is by heavy antibiotics.
d. .Tumors:
It arises from the skin & it includes SCC, basal CC & melanoma.
Treatment:
· ·Surgical excision of the tumor (wedged shape) & approximation of the tow
edges together.
· ·Skin graft may be needed if the skin loss is large.
· ·Radiotherapy may be needed.
B. Diseases of the external auditory canal:
a. Congenital:
Stenosis: is narrowing of the canalAtrasia: is complete or partial absence of the canal.
b. .Traumatic:
1. .Self-induced: when the patient tries to clean or scratch the EAC by a roughobject as a pen or a key.
2. .Iatrogenic: by rough removal of FB by untrained persons.
3. .Foreign body:
Traumatic injury to the EAC may be induced by FB usually in children
by themselves or may be done by a child to another child as part of their
playing together, the common age group is (2-4) yr. these FB can cause trauma &
secondary infection &/or secondary conductive deafness.
Generally FB can be classified as follows:
- -Inorganic FB (non-vegetable):
It’s considered, as inert material (does not induce tissue
reaction), not irritable, but it may cause trauma or obstruction e.g. (chalk,
plastic substances, metals).
Treatment: is by ear wash, suction or by special instruments.
- -Organic FB (vegetable):
These FB (e.g. beans, seeds) are irritable to the skin due to
certain chemical components causing inflammatory reaction & fluid secretion from
the skin, this fluid is absorbed by these FB causing its enlargement & further
obstruction & may lead to otitis externa.
The child may complain from pain, irritability & hearing
disturbances.treatment is the same as inorganic FB but these FB should be dealt
with as early as possible to reduce the inflammatory reaction.
- -Insects FB:
This condition is common in farmers when they get sleep
in the fields & in children with chronic ear discharge because the insects
prefer dark & humid areas (EAC). In chronic ear discharge the pus has a bad
odour that attract flies to lay down their eggs & then hatching to larvae
causing what is called: Maggots of the ear.
Treatment is by ear syringing, but if the insect is alive
it must be killed by application of few drops of alcohol or antiseptic
preparation & then examination of the ear for any trauma.
c. Inflammatory: (otitis externa)
Its either: viral (herpes simplex), bacterial (G-ve as pseudomonas
aeroginosa, G+ve as staph. aurius), or fungal (candida albicans, aspergillus
niger).
Etiology:
This type of infection occurs when there is a break in the skin because
healthy skin resists infection, so the infection must be preceded by some sort
of trauma as follows:
1. .Laceration.
2. .Scratching.
3. .Iatrogenic.
4. .Maceration by introduction of hot water (accidentally or iatrogenic) causing
sever type of otitis externa.
5. .Chronic ear discharge & pus goes to the EAC & induce infection.
Diffused bacterial otitis externa:
There is a diffused involvement of the EAC skin as in eczematous lesions.Clinical features:
1. .Pain in the ear especially during movement of the TM joint, swallowing &
eating.
2. .Blockages of the EAC in sever cases & the patient complains of partial or
complete conductive deafness.
3. .O/E sever tenderness on touching the auricle, signs of inflammation may be
seen (redness, swelling, tenderness & hotness).
4. .Pus is sometimes seen obscuring the TM.
5. .Pre-auricular lymph nodes may be enlarged & tender.
Treatment:
Systemic applications:
1. .Antibiotics: broad spectrum AB (penicillines, ampicilline) is needed to kill
both G+ve & G-ve bacteria, the dosage & rout of administration depend on the
severity of the condition.
2. .Analgesics: aspirin, paracetamole & voltarin. The type, dosage, route of
administration & frequency of application depend on the severity of the
condition.
Local measures:
1. .Suction clearance to clean the canal if possible.
2. .Dry mopping is another alternative.
3. .Gauze wick embedded in antiseptic, AB & steroid preparations.
Localized otitis externa (furunculosis or boil):
This type usually occurs in the cartilaginous part of the EAC (because it
contains skin appendages) usually due to infection of the hair follicles.
Organisms responsible for this type of infection are usually staph. aurius & the
usual predisposing factor is trauma.
Clinical features:
1. .Pain may spread to the jaw & side of the head & may extend to the neck &
shoulder.
2. .Hearing loss occur when there is obstruction of the EAC.
3. .O/E tenderness on the tragus(if the boil is anteriorly situated) or on the
mastoid area(if the boil is posteriorly situated), signs of inflammation may be
seen.
4. .The boil is seen as a bulge from the wall of the EAC, the TM is normal.if
left untreated an abscess is formed.
Treatment:
1. .Systemic AB & analgesics.
2. .Local measures as cleaning & packing with gauze wick.
3. .The abscess if formed it should be drained.
Malignant otitis externa:
It’s uncommon but aggressive and potentially fatal infection (10%
mortality) of the soft tissues of the external ear and surrounding structures,
quickly spreading to involve the periostium and bone of the skull base. It’s a
mixture of necrotizing external otitis and skull base osteomyelitis, and is the
end stage of a severe infection of the EAC which progresses through cellulitis,
chondritis, periostitis, osteitis and osteomyelitis.
Bacteriology:
Pseudomonas aeroginosa is the most common (95%) pathogen, rarely other
G-ve, G+ve, and aspergillus can cause the infection.
Predisposing factors:
1. Elderly.
2. Diabetes mellitus
3. Immunocomprised patients.
4. Histeocytosis or malignancy of the temporal bone.
Clinical features and diagnosis:
1. Pain: is usually severe but could be mild especially in diabetics.
2. Otorrhea.
3. Granulation tissue: usually in the posteroinferior part of the EAC at the
osteocartilagenous junction.
If the above three clinical features continue for more than 8-10 days of local
therapy, this is highly suggestive for the diagnosis.
4. Oedema of the EAC.
5. Culture of the exudates +ve for p.aeroginosa.
6. Cranial nerve palsy (mostly the VII cranial nerve).
7. +ve Technetium (Tc-99m) radionuclide bone scans, will detect bony
involvement even before high resolution CT scans.
8. CT scans of the temporal bone and skull base.
9. High ESR (more than 100) and C-reactive protein.
Spread:
The disease spread from the EAC to the parotid gland, temporomandibular joint,
and the soft tissue of the skull base.
Treatment:
1. Aural toilet: to control the granulations and improve local pain control.
2. Systemic antibiotics: ciprofloxacin with or without an aminoglycoside and\or
ceftazidime, then transition to oral therapy when the ESR and CRP start to fall.
3. Hyperbaric oxygen: in special centers.
4. Surgery in selected cases to remove sequestra, collections of pus and
debridment of necrotized and granulating tissues.
Otomycosis (fungal otitis externa):
It’s fungal infection of the skin of the EAC the organisms responsible
for this usually belong to the genus aspergillus (asp.niger) & to the genus
candida (cand.albicans or monillia).
Predisposing factors:
1. .The weather (common in summer than in winter).
2. .Topical application of antibiotic preparations.
3. .Simple contamination of the EAC skin by fungus after scratching the canal.
Clinical features:
1. .Itching is the main symptom of the disease.
2. .Sometimes moderate to sever pain.
3. .Conductive deafness if the EAC is obstructed by the debris.
4. .Tenderness may occur.
5. .Debris in the EAC characteristic of the disease called: wet newspaper (which
is accumulation of gray or brown debris with exfoliation of the skin forming
black spots.
Treatment:
1. .Removing of the debris by mopping or by vacuum sucker.
2. .Application of antifungal drugs as ear drops or cream e.g. nystatine or
clotrimazol.
3. .Keratolytics e.g. salicylic acid solution.
4. .Non-organic iodide & alcohol may be used.
Herpes zoster oticus(Viral infection of the EAC ):
Is an important viral infection of the EAC, it causes eruptions of the
skin with small size vesicles, the condition is very painful because it affect
the nerve ganglia(usually the cell body is affected not the axons) mainly that
of the facial nerve & somatic nerves of the skin.
The main complain is what is called: Ramsy hunt syndrome
(vesicles+facial nerve paralysis+deafness & vertigo).
Treatment:
Local &/or systemic steroids, antiviral agent (acyclover) orally or
systemically, analgesics to alleviate the pain & finally gentle cleaning with
mild antiseptic solution.
c. .Tumors 0f the EAC:
Benign tumors:· ·Sequamous epithelial tumors (papilloma or skin warts).
· ·Cartilaginous tumors (chondromas) a rare tumors.
· ·Bone tumors (ostioma, exostoses).
These tumors can be removed surgically without consequences by excisional
biopsy & send for histopathological study(bony tumors removed by drilling).
Malignant tumors:
· ·Sequamous cell carcinoma (the commonest type).
· ·Basal cell carcinoma.
· ·Melanoma or melanosarcoma (this tumor arise from the melanocytes of the
epidermis & it’s a very serious tumor, but is fortunately rare.
The S.C.C is presented as an ulcer in the floor of the proximal part of the
canal causing sever earache & sometimes show a bloody discharge & if its large
it may cause conductive deafness.
The diagnosis is by history (usually there is a long history of chronic
suppurative otitis media), examination & investigations.
Treatment: by surgical excision with a safety margin. Sometimes the surgery is
followed by radiotherapy, in cases of lymph node metastases neck dissection is
included & finally chemotherapy in advanced cases.
Wax of the EAC
This is a very common condition in the community, the cerumen is secreted
from the ceruminous glands (modified sebaceous gland) in the EAC & when itssecreted its pale –yellow in color & then changes to dark-yellow to
light-brown & then to dark-brown in color at last (due to hemosidirin oxidation
by air).
The cerumen is mixed with sequamous epithelia & after that it is expelled
laterally outside the EAC in the form of flacks, if this mechanism is disturbed
wax will accumulate closing the canal & causing conductive deafness.
Functions of the cerumen:
· ·Act as a lubricant.
· ·Protect the skin from infection by its acidic & antimicrobial
(lysosomal)activity.
· ·Protect the skin from trauma.
Etiology of wax impaction:
· ·Narrow canal.
· ·Mostly due to the attempt of a person to clean the EAC by
cotton buds which causes inward movement of the wax reaching to tympanic
membrane.
Signs & symptoms:
Mild to moderate conductive deafness, tinnitus, itching, vertigo &
discomfort.
The deafness begins mild but if the condition is neglected & the person
induces water in the ear as in bathing or swimming the wax will absorb water
because of its hydrophilic property & causes swelling of the wax & further
obstruction.
O/E there is a brown mass in the EAC obscuring the tympanic membrane.
Treatment:
The wax is usually removed by earwashing (syringing), but if the wax is hard
it should be softened by the use of lubricants (e.g. 5% sodium bicarbonate,
glycerin, olive oil) then removed by earwashing.
Technique of ear syringing:
The instrument used is 50 cc syringe, kidney dish to collect the debris. The
syringe is filled with sterile solution(normal saline, boiled water, water with
chlorine or antiseptic solution)at body temperature(37 c)to prevent stimulation
of the labyrinth & consequent vertigo(caloric stimulation).
The syringe should be directed postero-superiorly in the EAC with the other
hand pulling the pinna outward, backward & superiorly. The syringe should not
touch the EAC skin to prevent trauma & the irrigation should be gentle.
Earwash is contraindicated in the following:
1. .Chronic ear infection.
2. .History of ear surgery.
3. .Signs & symptoms of acute infection (pain, tenderness, fever).