Disorders of the External Ear Flashcards
What does Congenital mean?
Present at birth
What does Acquired mean?
not present at birth
What is the relation between the branchial arches and the structures in embryology?
Each branchial arches develop into a specific structure (muscle, skeletal, nerve and artery). If there is a problem during development, it can cause congenital disorders like otosclerosis.
Which part of the outer ear develops at week 4-6-8 of gestation?
4: EAC
6: Hillocks of His distinct
8: Pinna structures identifiable
Which part of the outer ear develops at week 18-20-28 of gestation?
18: Auricle adult form
20: EAC plug disintegrates
28: EAC fully open
What are the sensory innervation of the External ear?
Sensory innervation: CN V, VII, IX, X, and great auricular nerve (C2, C3)
What are the arteries that supply blood to the OE? (2)
superficial temporal and posterior auricular arteries
What can we say about the OE and lymphatic system?
OE contains Lymphatic parotid and cervical nodes (immune system)
Infections and inflammatory conditions of the EAC (& ear) can present with enlarged lymph nodes
What is Darwin’s tubercule?
Unique congenital prominence that may be found on the posterior helix of the ear
What are prominent ears?
Ears that stick out more than 2 cm from the side of the head are considered to be prominent or protruding
What is Cryptotia?
Ear cartilage framework that is partially buried beneath the skin on the side of the head.
What is Cup/Lop ear?
Ear deformity where the rim of the ear can be folded forward slightly, giving the appearance of a cup, or more severely, with the entire outer ear appearing as a roll
What is Stahl Ear?
consists of an extra cartilage fold in the scapha portion of the ear.
What is Microtia?
Absent or underdeveloped external ear.
What are preauricular pits?
little dimple in front of the ear
What is a preauricular skin tag?
Bump of skin next to ear
What is auricular hematoma?
Mass of blood in the OE
What can Auricular hematoma cause?
Can have CHL
EAC swelling
Hemotympanum (blood in middle ear)
Ossicular injury/discontinuity
How do you treat auricular hematoma?
incision and drainage
What causes cauliflower ear?
- Occurs secondary to hematoma
- Auricular trauma - auricular hematoma - cauliflower ear (if hematoma left untreated)
- Hematoma disrupts blood supply to auricular cartilage which leads to cartilage necrosis (death) and neocartilage formation
What is Cellulitis?
Cellulitis = inflammation/infection of skin
Pain (on touch)
Warmth
Erythema (redness)
Edema (swelling)
Pruritus (itching)
Weeping & crusting
What is Chondritis?
Chondritis = inflammation/infection of cartilage
(lobule is sparred)
What is perichondritis?
Inflammation of skin over the cartilage (perichondrium)
What can cause Cellulitis, Perichondritis, and Chondritis? (4)
Trauma (usually penetrating)
Piercings
Ear surgery (iatrogenic)
Underlying conditions (eg diabetes, immunosuppression)
How do we treat Cellulitis, Perichondritis, and Chondritis? (2)
Antibiotic treatment
Incision and drainage for abscess
Can Cellulitis, Perichondritis, and Chondritis cause hearing loss?
CHL possible but rare
What can cause weather-related injuries?
Frostbite
Sunburn
What are the susceptible factors of weather-related injuries? (4)
Malnutrition
Dehydration
Prolonged exposure
Poor hygiene
What can frostbite cause?
Superficial ->Deep
Erythema (light skin) or gray color (dark skin)
Tingling, stinging sensation
Numb, yellow, waxy/shiny, gray color
Feels cold, stiff, woody
Blisters
Black necrosis (tissue death)
What can cause sunburn?
Winter -> Summer
Fair skin, light hair (red hair)
Exposed skin areas
Snow can reflect sunlight
UV light
Major risk factor for skin cancer
What is 1st degree sunburn?
Superficial: red, tender, slightly swollen
What is 2nd degree sunburn?
Superficial: very red, swollen
What is 3rd degree sunburn?
Mid-level: severe blisters, peeling skin, nerve damage (no pain)
What is 4th degree sunburn?
Deep: death of soft tissue, muscle, cartilage, bone
How do you treat sunburn on ears?
1st degree burn-no referral needed (heals in 1 wk)
Other burns requires urgent treatment
Do frostbite and sunburn cause hearing loss?
Very rare, it must swell or obstruct the canal to some degree
- Ear canal swells
- Secondary infection
- Physical damage to pinna
- Tympanic membrane involvement
What are Dermatological Conditions?
Skin conditions that can affect the auricle and/or ear canal
What Seborrheic Dermatitis?
Dermatological Conditions where there is an inflammatory skin
- Eczema like condition
- Scaly, flaky, itchy, and red skin
- Affects sebaceous gland rich areas
- May affect postauricular regions and EAC
What is Actinic Keratosis?
Dermatological Conditions, Pre-malignant lesion caused by sun exposure
- Thick, crusty patches of skin
- Can progress to SCC
- Early removal is recommended (surgery, laser, liquid nitrogen)
What is Cutaneous Horn?
Dermatological Conditions, Conical projection above skin surface
Resembles a “horn”
Composed of compacted keratin
Base may be malignant
Requires surgical excision
What is Staphylococcal Dermatitis?
Bacterial skin infection caused by staph aureus
Can be associated with hearing aid molds and poor hygiene
What can cause skin cancer?
Sun exposure (UV light)
Skin type
Immunosuppression
Chronic inflammation
Genetic predisposition
What is the most common human skin cancer?
Basal Cell Carcinoma
20% of all cancers in men
10-15% of all cancers in women
85% of all BCC occur in _______ & _______
85% of all BCC occur in head & neck
85% of all BCC occur in _______ & _______
85% of all BCC occur in head & neck
What is squamous cell carcinoma?
- More aggressive than BCC
- Higher incidence of metastasis
- Often a progression from sun-damaged areas (eg actinic keratosis
- Erythematous, crusting, ulcerated lesion with friable base
What is the most aggressive type of skin cancer?
Melanoma
- 75% of deaths caused by skin cancers
- Derived from melanocytes (produce melanin)
What are the features of melanoma? (ABCDE)
- Asymmetry
- Borders (irregular)
- Colour (variegated)
- Diameter
- Evolving over time
What are features of the EAC?
Outer 40% is cartilaginous
Inner 60% is bony
Skin overlying bony canal
Skin, hair, and sebaceous glands overlying cartilaginous canal
Sebaceous glands produce wax for protection
Narrowest point at bony-cartilaginous junction (isthmus
How do you remove excessive cerumen?
- Small amount and not obscuring view-leave alone
- Irrigation/flushing (TM must be intact)
- Ear drops (oils, acetic acid, cerumenex; TM must be intact)
What is Aural Atresia and stenosis?
Atresia-complete absence of EAC (no connection to middle ear)
Stenosis-narrowing of EAC
Congenital cause of CHL
What is Otomycosis?
- Fungal infection of the EAC
- Fungal elements visible
- Aspergillus fumigatus, Aspergillus niger, Candida albicans are most common forms
What is Otitis Externa?
Inflammation/infection of the EAC
Bacteria induced
Most common condition that affect the EAC
Acute and chronic types
What is Otitis Externa?
Inflammation/infection of the EAC
Bacteria induced
Most common condition that affect the EAC
Acute and chronic types
What can cause Otitis Externa?
- Ear canal skin is injured by trauma/humidity exposure
- Normal protective wax layer is disrupted
- Bacteria
What is Acute otitis Externa?
- Acute Infection of the EAC by Pseudomonas auriginosa (most commonly)
- Causes
Spontaneous/idiopathic
Local trauma
Frequent swimming
Chronic OE
What is Acute otitis Externa?
- Acute Infection of the EAC by Pseudomonas auriginosa (most commonly)
- Causes
Spontaneous/idiopathic
Local trauma
Frequent swimming
Chronic OE
What can Otitis Externa cause? (3)
Otalgia (severe) with ear movement
Otorrhea
Pruritis
EAC swelling and collection of debris/discharge
CHL
How can you treat Acute Otitis Externa?
Analgesics
Antibiotic/anti-inflammatory drops
Aural toilet (refer to ENT)
Counseling for prevention
What is Necrotizing Externa Otitis?
- Aka malignant external otitis
- Infection of the temporal bone
- Osteomyelitis - Mostly affects elderly with diabetes
- Immunosuppressed - Often preceded by EAC trauma or OE
What are features of Necrotizing Externa Otitis? (3)
Severe otalgia
Otorrhea
Graulation tissue
Cranial nerve weakness
- Facial palsy
Intracranial complications
May be lethal
What foreign bodies are common with children in the External ear canal?
Toys and Bugs
What is Exostosis?
Bony growths in the EAC (multiple)
Frequently bilateral
Arises near the annulus/TM
Associated with prolonged cold water exposure
May cause CHL
What is Exostosis?
Bony growths in the EAC (multiple)
Location
Frequently bilateral
Arises near the annulus/TM
Radiographic appearance
Broad base
Solid
Associated with prolonged cold water exposure
May cause CHL
What is Osteoma?
Bony growths in the EAC (solitary)
Unilateral
Lateral EAC
Radiographic appearance
Not solid
Pedunculated (on a stalk)
No association with cold water exposure
Typically no CHL
What is Osteoma?
Bony growths in the EAC (solitary)
Location
Unilateral
Lateral EAC
Radiographic appearance
Not solid
Pedunculated (on a stalk)
No association with cold water exposure
Typically no CHL
