Outer ear disorders Flashcards
a) . What are earwax?
b) . What are their functions?
a) . Earwax is a normal physiological substance that consists of dead cells (desquamated keratin), cerumen (wax-like substance), sebum, and various foreign substances such as cosmetics and dirt
b) . It cleans, lubricates, and protects the lining of the ear canal, trapping dirt, dust, and hair, and repelling water. It’s acidic so it inhibits the growth of bacteria and fungi
What is the pathophysiology of earwax impaction?
Normally, earwax is eliminated from the ear canal spontaneously through natural jaw movement. If the natural elimination mechanism is disrupted or inadequate, wax is retained in the canal and may become impacted
Earwax impaction is also caused by:
- Overproduction of earwax
- Obstruction due to variations in the anatomy of the ear canal
- Inadequate epithelial migration
- Cerumen glands become atrophied as you age, resulting in drier earwax, which is a lot harder to be transported by the epithelial migration. Also the process of epithelial migration is also slower as you age
- Cerumen phenotype
- Dry earwax (brittle and dry, often light/ brownish grey in colour) - predominent in Asian and American people
- Wet earwax (wet and sticky, often dark in colour) - predominent in African and European people
Give 5 risk factors for earwax impaction
Risk factors
Age > 50 yrs old
Men
Age < 5 yrs old
Narrow/ deformed ear canals
Down’s syndrome
Dermatological conditions - atopic eczema, psoriasis
Use of cotton buds (can push earwax deeper into the canal)
Repeated insertion of hearing aids or earplugs
Give 3 complications of earwax impaction
Hearing loss and earache
Infections
Affect work and school performance as it may affect hearing
Depression, social isolation
What are the clinical features of impacted earwax?
Presentations:
- Conductive hearing loss
- Ear ache or discomfort
- Blocked ears
- Feeling of fullness in the ear
- Tinnitus
- Vertigo
- Itchiness
- Cough (rare and it’s due to stimulation of the auricular branch of the vagus nerve by pressure from the impacted eareax)
Give 5 differential diagnoses of impacted earwax
Otitis externa
FB in ear canal (esp in children)
Polyp of the ear canal
Cholesteatoma
Osteoma of the ear canal (slow-growing and benign)
Fibrous dysplasia affecting the bony ear canal
What is the management of impacted earwax?
Mx:
- Note that in most cases, ear wax does NOT need to be removed as they are part of the physiological process of cleaning and protecting the ear canal. However, offer earwax removal if:
- Patient is symptomatic e.g. hearing loss, blocked ears, ear ache/ discomfort, tinnitus, vertigo
- The tympanic membrane is obscured by wax but needs to be viewed to establish a diagnosis
-
Ear drops (Sodium bicarbonate 5% ear drops, olive or almond oil drops) to soften wax and aid removal
- Advice:
- Advise to use the drops 3 times daily for 3-5 dailys initially
- Warn the person that ear drops may cause transient hearing loss, discomfort, dizziness, and skin irritation
- Advise that removal of earwax may not necessarily relieve the symptoms, for example, hearing loss maybe sensorineural loss and not due to impacted earwax
- Contraindications to ear drops:
- Perforated eardrum
- Grommets
- Active dermatitis
- Acute otitis externa
- Allergies (e.g. to almond)
- Advice:
- If symptoms persist after the use of ear drops:
-
Ear irrigation (also known as ‘ear syringing’), OR
- Same contraindications as above
- Microsuction
-
Ear irrigation (also known as ‘ear syringing’), OR
Give 3 contraindications of ear drops/ ear irrigation
Perforated eardrum
Grommets
Active dermatitis
Acute otitis externa
Allergies
Describe the sensory supply to the pinna
Sensory supply to the external ear:
- Auriculotemporal nerve (CNV3) - supplies upper lateral surface
- Greater auricular nerve (from cervical spinal roots C2-3) - supplies lower lateral surface and medial surface
- Lesser occipital nerve (C2-3) - supplies upper medial surface
- Auricular branch of vagus nerve (CN10) - supplies the EAM - if this is touched with a cotton wool bud it can elicit the gag reflex from the vagus nerve
What causes a pinna haematoma to form and why is it a medical emergency?
Blunt trauma (very common among boxers, rugby players, wrestlers) to the ear can cause a haematoma to form!
Normally, the cartilage obtains nutrients via diffusion from vessels in the overlying perichondrium. However, when bleeding occurs, the blood strips the perichondrium from the underlying cartilage and deprives the cartilage of oxygen. If left untreated, avascular necrosis of the cartilage occurs –> cauliflower ear
How do you manage a pinna haematoma?
Immediate hospital admission + same day assessment by ENT
*Urgent aspiration/ drainage of the haematoma + apply a firm pressure dressing for 24 hrs to prevent re-accumulation + re-examination of the ear
Haematomas often clot and cannot be aspirated. In such cases, the blood is curetted out after raising a skin flap, then pressure is applied for days and Abx are administered to prevent infection
How do you manage ear lacerations?
Mx:
- Clean the wound first and then close the skin with sutures
- Ensure that any exposed cartilage is covered with skin
- If significant skin loss where primary closure is not possible –> plastic input
How do you manage bites to the ear?
Mx:
- Bites to the ear carry a significant risk of infection from skin commensals, or oral commensals from the offending creature/ person, often resulting in perichondritis. Therefore, management includes leaving the wound open, thorough wound irrigation, Abx, and dressing the wound and delaying primary closure for 2-3 days
What are the causes of tympanic perforation?
What are the symptoms of tympanic membrane perforation?
Tympanic membrane perforation can be caused by direct or indirect trauma:
- Direct trauma e.g. head injury or cotton bud
- Indirect trauma e.g. barotrauma (scuba diving), infection (otitis media)
Presentations:
- Ear pain
- Conductive hearing loss
How do you manage tympanic membrane perforation?
Most perforations will heal by themselves –> conservative “watch and wait” approach + avoid water in ear
If the perforation does not heal by 6 months –> surgery (myringoplasty) to repair the eardrum
