Diseases of external ear Flashcards
Congenital auricular appendages and aural fistula location and aetiology
found anterior to the auricle
They are due to incomplete closure of the first branchial groove or an incomplete fusion of auricular hillocks
The different types of apppendages
simple skin tags to complex structures containing cartilage
Dangers of excision of aural fistulae
danger of damage to the facial nerve or parotid gland.
Congenital atresia of the external auditory canal: definition
This is complete closure of the external auditory canal, which is caused by a failure of canalisation of the epithelial plug portion of the first branchial cleft
The type of atresia in Congenital atresia of the external auditory canal
The atresia is bony in most cases, and less often membranous
Clinical features of congenital atresia of the external auditory canal
malformation of the middle and/or inner ear
Ossicular malformations
atresia or aplasia of the external auditory canal may occur as an isolated malformation
conductive hearing loss
sensorineural hearing loss
Diagnosis of Congenital atresia of the external auditory canal
At birth, when a malformed auricle or atretic canal is noticed in a newborn.
An audiological assessment is carried out to rule out hearing impairment in the infant.
Imaging of the temporal bone is necessary for accurate diagnosis and in decision making in therapy.
CT scanning
(BAHA)
First line of treatment Congenital atresia of the external auditory canal
In patients with bilateral abnormalities
Acute otitis externa
It is an infection of the hair follicles, most often caused by Staphylococcus aureus, which may progress to form an abscess or furuncle.
Acute otitis externa Clinical features
Severe pain in the ear elicited by moving or putting pressure on the auricle is characteristic
Treatemnt of Acute otitis externa
Topical antibiotics or local antiinflammatory drugs can be used. A localised abscess should be treated by incision and drainage and oral or local antibiotics.
Acute otitis externa – diffuse
Otitis externa or “Swimmer’s ear” is a bacterial infection of the external ear canal, with an incidence of 4/1000 children and adults per year; 80% of cases occur in summer
Acute otitis externa – diffuse
aetiology
It is caused by an abrogation of the protective lipid film of the external canal, which exposes the epithelium to water and other contaminants
Predusposing factors to Acute otitis externa – diffuse
heat, humidity, frequent swimming, anatomic obstruction of the ear canal (stenosis, exostosis, impacted cerumen), hearing aids, ear plugs, foreign bodies, and middle ear discharge
Most common;y isolated dorganisms in Acute otitis externa – diffuse
Pseudomonas aeruginosa,
Proteus mirabilis and
S. aureus
Clinical featuress of Acute otitis externa – diffuse
pain, itching, aural fullness, decreased hearing, and otorrhoea.
A typical sign is pain elicited by tragal pressure or by pulling on the auricle.
The lumen of the external auditory canal is narrowed by oedema and debris from the thickened and irritated skin
Treatment of Acute otitis externa – diffuse
e careful atraumatic cleaning of the external ear canal using a microscope,
drying of the ear canal,
frequent inspection,
and control of pain
Necrotising (malignant) otitis externa
Malignant otitis externa is a very aggressive form of otitis externa, typically seen in elderly people and people with diabetes. It is a potentially lethal infection of the auditory canal, surrounding tissue and skull base.
Most common pathogen in Necrotising (malignant) otitis externa
Pseudomonas aeruginosa.
Necrotising (malignant) otitis externa clinical features
severe otalgia, granulation tissue in the meatus, and facial nerve paralysis.
Treatment of Necrotising (malignant) otitis externa
hospitalisation, treatment of diabetes, use of high-dose intravenous antibiotics specific for Pseudomonas, and sometimes surgery
Cellulitis of ear
Cellulitis of the auricle is a bacterial infection; it often follows an ear piercing or laceration.
Clinical features of cellulitis
Symptoms are pain with a red and swollen auricle.
Treatment of cellulitis
consists of oral or intravenous antibiotic and wound care
Perichondritis def
Perichondritis or chondritis is an infection of the perichondrium or cartilage of the auricle
Aetiology of Perichondritis an causative pathogen
It usually arises from improper treatment of cellulitis or otitis externa. The most common pathogen is Pseudomonas sp
Clinical features of Perichondritis
The affected ear is oedematous,
and painful, with
serous or purulent exudates
treatment of Perichondritis
aural cleaning, local and oral antibiotics (fluoroquinolones) and, in severe cases, hospitalisation and intravenous antibiotics
Complictions of Haematoma of the auricle
disruption of a perichondrial blood vessel,
accumulation of blood in the subperichondrial space,
and separation of the perichondrium from the cartilage
Treatment of Haematoma of the auricle
evacuation of the haematoma; the method of choice is adequate incision and drainage, followed by compression dressing and antibiotics
Frost bite of auricle
severe and prolonged vasoconstriction of the capillary walls, resulting in damage to these walls
red, swollen and tender
Treatment of auricle frostbite
antibiotics and analgesics should be used. Rewarming with sterile dressings is usually successful; debridement of gangrenous tissue may be required
What leads to perichondritis if untreated
Burns
Where is cerumen produced?
produced in the outer third of the cartilaginous portion of the ear canal.
The primary components of cerumen are
desquamated layers of skin, with 60% of the cerumen consisting of keratin, 12–20% saturated and unsaturated long-chain fatty acids, alcohols, and squalene, and 6–9% cholesterol
Functions of cerumen
Cerumen protects the skin, assists in lubrication, and also provides some protection from bacteria, fungi, insects and water
Usuaul Foreign bodies in the external auditory canal
Food (nuts, beans), stones, little toys and other small objects, and cotton from cotton swabs in adults are common
