Chapter 5: Diseases of the External Ear Flashcards
Auricle/Pinna (Portion)
Cartilaginous portion (outer 1/3) MOBILE Bony portion (inner 2/3)
External ear (Function)
- Collect and funnel sound waves to the middle ear structures
- Protects the TM from injury
External auditory canal (length)
- 2.5 cm long
2. Extending from the anterior lip of the concha to the TM
Narrowest area of the canal
Bone-cartilage junction
Upon inserting otoscope, the auricle should pull…
Posterolateral
Susceptible to infection
Epithelium-line pouch (can trap moisture)
Skin lining of cartilaginous portion
- Thicker than the bony portion
2. Contains hair follicle
- The only place in the body where there is skin directly overlying bone with no subcutaneous tissue
- Extremely sensitive and any swelling is very painful (no room for expansion)
Bony external auditory canal
Provides protection through formation of cerumen or ear wax
External ear
Location of glandular structures, sebaceous and apocrine glands that produce cerumen
Cartilaginous portion
Provides a protective, water-repellent coating to the canal
Cerumen + exfoliated cells of the stratum corneum
pH of cerumen
6 (acidic)
Provides a cleansing mechanism form the TM outward
Migration of desquamated epithelial cells
Ear canal infections are more common in a…
Warm, humid environment
More common presenting symptoms of conditions involving the auricle and external auditory canal
- Pain (otalgia)
- Itching
- Swelling
- Bleeding
- Blocked sensation
Product of both sebaceous and apocrine glands which are located in the cartilaginous portion of EAC
Cerumen
Types of cerumen
- Wet (dominant)
2. Dry
Has bactericidal properties
Cerumen
Acts as a vehicle for the removal of epithelial debris and contaminants away from the TM
Cerumen
Provides lubrication and prevents desiccation of the epidermis with its associated fissuring
Cerumen
Components of cerumen that are believed to be inhibitory or bactericidal
- Fatty acids
- Lysozyme
- Immunoglobulin
Drier in older individuals because of…
- Atrophy of the apocrine gland
2. Lessening of the sweat component of the cerumen
May present as a keratin plug occluding the EAC
- Keratosis obturans
2. Cholesteatoma
Bilateral and may present with bronchiectasis and chronic sinusitis
Keratosis obturans
Patients presents with pain and hearing loss
Keratosis obturans
- Widening of external canal
- Hyperplasia
- Inflammation of the epithelium and subthelium
- No bony erosion
Keratosis obturans
Postulated theory of keratosis obturans
- Overproduction of squamous epithelium and squamous plugs
2. Faulty migration of the epithelium
Management of keratosis obturans
- Plug removal
2. Treatment of inflammatory process
Usually unilateral and patients present with dull pain and intermittent otorrhea due to bony erosion and secondary infection
Cholesteatoma
Postulated theory of cholesteatoma
- Circumscribed periostitis
2. Faulty epithelial migration
Management of cholesteatoma
- Debridement of the bone or canalplasty
2. Tympanomastoidectomy
External Otitis: Predisposing factors
- Change from the normally acid pH of canal skin
- Increased temperature and humidity
- Trauma (excessive swimming or cleaning of the ear)
Management of external otitis
- Careful cleaning of the canal
- Evaluation of discharge, canal wall edema and TM
- Selection of local medication
AKA Furunculosis
Otitis External Circumscripta
Furunculosis begins in a…
Pilosebaceous follicle
Furunculosis is confined to the…
Fibrocartilaginous portion of the external auditory meatus
Furunculosis is usually caused by…
Staphylococcus aureus or Staphylococcus albus
AKA swimmer’s ear
Diffuse otitis externa
Swimmer’s ear is caused predominantly by…
Pseudomonas group
Less:
Staphylococcus albus
Escherichia coli
Enterobacter aerogenes
Diagnostic features of Diffuse otitis externa
- Tragal tenderness
- Severe pain
- Canal wall swelling
- Scanty discharge
- Normal or slightly diminished hearing
- Absence of obvious fungal particles
- Possible presence of tender regional adenopathy
Most common caused of Otomycosis
- Pityrosporum
2. Aspergillus
AKA Herpes zoster oticus
Ramsay hunt disease
Facial paralysis accompanied by otalgia and a herpetic eruption involving portions of the external ear
Herpes zoster oticus
Develops when trauma or inflammation cause an effusion of serum or pus between the layer of perichondrium and the cartilage of external ear
Perichondritis
Diagnostic features of Perichondritis
- Red
- Warm
- Tender
Lesion that involves the external canal and adjacent portions of the meatus and concha
Characterized by redness, itching, swelling and stage of water exudation followed by crusting
Eczematous dermatitis
Management of eczematous dermatitis
Wet dressing using a solution (Burow’s) for 24-48 hours + fluorinated steroid ointment and solution
Severe infection involving the temporal bone and soft tissue of the ear
Necrotizing external otitis
Necrotizing external otitis is caused by…
Paeudomonas aeroginosa
Necrotizing external otitis is generally found in…
Elderly diabetics
Necrotizing external otitis is considered more common in…
Warm climates
Should evaluated carefully for other symptoms indicating necrotizing external otitis
Patients with recalcitrant external otitis of more than 2 weeks duration
Favored mode of treatment of Necrotizing external otitis
Extended mastoidectomy
First line of therapy in Necrotizing external otitis
Systemic antibiotic intervention
Surgery of Necrotizing external otitis be limited to the..
- Removal of sequestra
- Drainage of abscesses
- Local debridement of granulation tissue
Recommended drug therapy in Necrotizing external otitis
Aminoglycoside + anti-Pseudomonas beta-lactam antibiotic
Prolonged therapy of at least 6 weeks is recommended
Disease of unknown etiology leads to inflammation and destruction of cartilage
Generalized disorder of cartilage, involvement of the nose and ears (80-90%)
Relapsing polychondritis
Relapsing polychondritis may also involved
Larynx
Trachea
Bronchi
May present as hoarseness even death due to collapse of laryngotracheal and bronchial walls
Most common cause of lacerations
Digging in an ear with a finger or using an instrument
Management of ear lacerations
Keep the ear dry
Management of frostbite
Rapid rewarming in water between 100 and 108F
Injury due to frostbite is due to…
- Direct cellular damage
- Microvascular insult
Leading to local ischemia
Untreated hematoma of the ear may result in the so-called…
Cauliflower ear
Management of ear hematoma
I and D of collected blood under sterile conditions followed by the application of a pressure dressing
Most common auricular deformity
Lop-ear deformity
Types of 1st branchial cleft abnormalities
Type I: ectodermal tissue only, free of cartilage, 1st cleft origin only
Type II: epithelium of 1st cleft origin and cartilage from 1stand 2nd arches
Benign tumor of the external canal wall which presents as a single, firm, rounded growth attached by a small bony pedicle to the inner third of the canal wall
Osteoma
More common and which consists of a rounded protuberance of hypertrophic canal bone (multiple and bilateral)
Exostosis
Management of osteoma
Chiseled from the canal wall with the aid of the operating microscope
Most common malignancy of the EAC
Squamous cell carcinoma
Nodules involving the helix may represent localized areas of chondritis
Chondrodermatitis nodularis chronicis helicis (painful nodule)