List I - Core Conditions

Question 1

What is otitis externa?

Answer 1

• Inflammation of the external ear canal

Question 2

How can otitis externa be further catagorised?

Answer 2

• Localised otitis externa
• Diffuse otitis externa
• Acute
• Chronic
• Malignant

Question 3

What is localised otitis externa?

Answer 3

• Folliculitis (infection of a hair follicle) that can progress to become a furuncle (boil) in the ear canal

Question 4

What is diffuse otitis externa (aka swimmers ear or tropical ear)?

Answer 4

• Widespread inflammation of the skin and sub-dermis of the external ear canal which can extend to the external ear and the tympanic membrane

Question 5

When is otitis externa classed as acute?

Answer 5

• If it has lasted for 3 weeks or less

Question 6

When is otitis externa classed as chronic?

Answer 6

• If it has lasted for longer than 3 months

Question 7

What is malignant otitis externa?

Answer 7

• Aggressive infection that predominantly affects people who are immunocompromised or have DBM or the elderly
• Otitis externa spreads into the bone surrounding the ear canal (the mastoid and temporal bones - known as necrotising otitis

Question 8

What are the causes of acute diffuse otitis externa?

Answer 8

• Bacterial infection
• Most common with pseudomonas aeruginosa or staphylococcus aureus
• Fungal infections
• Superficial - aspergillus species or candida albicans
• Deep (of the stratum corneum) due to - epidermophyton, trichophyton or microsporum genera
• Seborrhoeic dermatitis
• Contact dermatitis
• Trauma - scratching, aggressive cleaning, ear synringing, foreign objects in the ear, use of cotton buds, hearing aids or ear plugs
• Environmental factors - high temperature and/or high humidity, perspiration, swimming (especially in polluted water)

Question 9

What are the causes of chronic diffuse otitis externa?

Answer 9

• Allergic contact dermatitis
• Irritant contact dermatitis
• Seborrhoeic dermatitis
• Fungal infection
• Bacterial infection
• Localised otitis externa - usually caused by infection of a hair root by staphylococcus aureus
• Idiopathic

Question 10

What are the risk factors for malignant otitis externa?

Answer 10

• Diabetes mellitus - present in most cases of malignant otitis
• Compromised immunity such as from HIV/AIDS, chemotherapy or CKD
• Radiotherapy to the head or the neck
• Aural irrigation with tap water, especially in people with other risk factors

Question 11

What are the possible complications of otitis externa?

Answer 11

• Abscess
• Chronic otitis externa
• Regional dissemination of infection with auricular cellulitis, chondritis, parotitis, spreading cellulitis
• Fibrosis, leading to stenosis of the ear canal and conductive deafness
• Myringitis (inflammation of the tympanic membrane)
• Tympanic membrane perforation
• Malignant otitis (complications of this include):
• Facial nerve paralysis
• Meningitis

Question 12

What is the prognosis for acute diffuse otitis externa?

Answer 12

• Symptoms of acute otitis externa usually improve within 48 - 72 hours of initiation treatment
• Between 65-90% of patients with uncomplicated diffuse otitis externa have clinical resolution within 7 to 10 days, regardless of the topical medicine used

Question 13

What is the prognosis of localised otitis externa?

Answer 13

• Folliculitis may heal on its own after an initial period of itching and pain or
• It may develop into a pustule (i.e. furuncle) with increasing discomfort, which, without treatment, will burst, drain and finally heal

Question 14

What is the prognosis of chronic otitis externa?

Answer 14

• Lumen of the ear canal progressively narrows, and after several years, may become completely stenosed, resulting in deafness in the affected ear

Question 15

What is the prognosis of malignant otitis?

Answer 15

• Without treatment, this can be a fatal condition - osteomyelitis will progressively involve the mastoid, temporal, and basal skull bones and the infection will spread to the CSF causing meningitis

Question 16

Who is otitis externa more common in?

Answer 16

• Can affect all ages

* Incidence peaks at 7 - 12 years and declines in those aged over 50

Question 17

What are the signs of otitis externa?

Answer 17

• Ear canal or external ear, or both, are red, swollen, or eczematous with shedding of the scaly skin.
• Swelling in the ear canal is typical of an early presentation of localized otitis externa; later the swelling has a white or yellow centre filled with pus; occasionally this progresses and the swelling eventually completely occludes the ear canal.
• Discharge (serous or purulent) may be present in the ear canal.
• Inflamed eardrum, which may be difficult to visualize if the ear canal is narrowed or filled with debris

Question 18

What are the symptoms of otitis externa?

Answer 18

• Itch (typical).
• Severe ear pain, disproportionate to the size of the lesion (typical).
• Pain made worse when the tragus or pinna is moved, or when an otoscope is inserted (typical).
• Tenderness on moving the jaw.
• Tender regional lymphadenitis — may be present (less common).
• Sudden relief of pain if the furuncle in localized otitis externa bursts (rare).
• Loss of hearing if there is sufficient swelling to occlude the ear canal (rare)

Question 19

What are the signs and symptoms of chronic otitis externa?

Answer 19

• Signs
• Lack of earwax in the external ear canal
• Dry hypertrophic skin which varies in thickness but often results in at least partial canal stenosis
• Pain on manipulation of the external ear canal and auricle
• Symptoms
• Constant itch in the ear
• Mild discomfort
• Pain, if present, is usually mild

Question 20

What are the signs and symptoms of malignant otitis externa?

Answer 20

• Signs:
• Granulation tissue at bone–cartilage junction of ear canal; exposed bone in the ear canal.
• Facial nerve palsy (drooping face on the side of the lesion).
• Temperature over 39°C.
• Symptoms:
• Pain and headache, more severe than clinical signs would suggest.
• Vertigo.
• Profound hearing loss

Question 21

What are the alternative diagnoses for otitis externa?

Answer 21

• AMO
• Foreign body in the ear
• Impacted ear wax
• Cholesteatoma
• Mastoiditis
• Malignant otitis
• Neoplasm
• Referred pain
• Ramsay Hunt syndrome
• Barotrauma
• Skin conditions

Question 22

How should a person with localised otitis externa be managed?

Answer 22

• Treat the pain if present
• Analgesic and local heat
• Treat infection if necessary
• Only consider an oral antibiotic for people with severe infection, or at high risk for severe infection for example:
• Furunculosis or cellulitis spreads beyond the ear canal to the pinna, neck or face
• Signs of systemic infection such as fever
• The person has a medical condition which is associated with increased risk of severe infection (DBM or compromised immunity)
• If oral anti-biotic is required consider a 7 day course of flucloxacillin or clarithromycin if the person is allergic to penicillin
• Drain the pus if necessary - if causing severe pain and swelling

Question 23

How should a person with acute diffuse otitis externa be assessed?

Answer 23

• Assess severity of symptoms
• Itch
• Hearing loss
• Ear discharge
• Severity of inflammation (more likely to be severe if any of the following are present)
• Fever
• Cellulitis spreading beyond the ear
• Regional lymphadenopathy
• Discharge (serous or purulent)
• Hearing loss (conductive)
• Red, oedematous ear canal narrowed and obscured by debris
• Examine the ear canal, tympanic membrane, the aurical and cervical nodes
• Can be difficult to adequately visualise the tympanic membrane in people with otitis externa, perforation can be assumed if the person has had a tympanostomy tube inserted in the past 12 months and there is no documentation of extrusion and closure of the tympanic membrane
• Can blow air out of the ear when the nose is pinched or
• Can taste medication placed in the ear
• Consider taking an ear swab to determine the causative organism

Question 24

When should an ear swab be taken for a person with otitis externa?

Answer 24

• To determine the causative organism if:
• Treatment fails
• Otitis externa is recurrent or chronic
• Topical treatment cannot be delivered effectively (for example if the ear canal is occluded due to swelling or debris)
• Infection has spread beyond the external auditory canal
• Condition is severe enough to require oral antibiotics

Question 25

How should a swab be taken from a person with otitis externa?

Answer 25

• Take a swab from the medial aspect of the ear canal under visualisation to reduce contamination

Question 26

How should a person with acute otitis externa be managed?

Answer 26

• Manage any aggravating or precipitating factors
• Consider cleaning the external auditory canal of earwax or debris obstructs the application of topical medication (this may require referral to an ENT specialist)
• Prescribe analgesic for symptomatic relief if required - paracetamol or ibuprofen, codeine can be added for severe pain
• Consider prescribing a topical antibiotic with or without a topical coticosteroid
• Use for a minimum up to a maximum of 14 days
• Topical acetic acid spray 2% is safe and effective can be used for mild cases
• Be aware of amino-glycoside induced ototoxicity in people with a perforated TM

Question 27

Although oral antibiotics are rarely indicated for acute otitis externa, when are they considered?

Answer 27

• Cellulitis extending beyond the external ear canal
• When the ear canal is occluded by swelling and debris and a wick cannot be inserted
• People with DBM or compromised immunity for severe infection for example with pseudomonas aeruginosa
• For these presentations consider prescribing a 7 day course of flucloxacillin or clarithromycin (if penicillin allergic)

Question 28

How should a person with chronic otitis externa be assessed?

Answer 28

• Assess in the same way as for people with acute otitis externa, in addition, assess for:
• Severity of itching (usually the most prominent symptom) and signs of scratching.
• Signs of fungal infection in the ear canal — whitish cotton-like strands of Candida, or small black or white balls of Aspergillus.
• Signs of generalized dermatitis — mild erythema and lichenification (thickening of the skin) in the ear canal, and signs of underlying disease elsewhere (for example seborrhoeic dermatitis, psoriasis).
• Evidence of contact allergy or sensitivity — use of ear plugs, hearing aid, earrings, sensitizing medications (topical and systemic).
• Evidence of a source for an id (auto eczematization) reaction — id reactions can result from an infection or inflammatory skin condition
• Fungal infection elsewhere in the body for example skin, nails, vagina) can cause a secondary inflammatory process in the external ear canal (presents as an itchy rash with blisters or vesciles)

Question 29

How should a person with chronic otitis externa be managed?

Answer 29

• May be challenging and may require more than one strategy
• If fungal infection is suspected (signs of fungal growth in the ear canal):
• Prescribe a topical anti-fungal preparation
• Mild to moderate and uncomplicated infections consider one of the following options:
• Clotrimazole 1% solution
• Acetic acid 2% spray
• Clioquinol and a corticosteroid (e.g. Locorten-Vioform)
• If the cause is:
• Irritant or allergic dermatitis - advise the person to avoid contact with the irritant or allergen and prescribe a topical corticosteroid
• Seborrhoeic dermatitis - treat topically with an antifungal/corticosteroid combination
• If no cause is evident:
• Prescribe a 7 day course of a topical preparation containing only a corticosteroid without anti-biotic (consider co-prescribing an acetic acid spray)
• If there is an adequate response, continue the corticosteroid treatment however reduce the potency of the corticosteroid and/or the frequency of the application to the minimum required to maintain control - if the course is inadequate, consider a trial of a topical anti-fungal preparation
• If treatment needs to be continued beyond 2 or 3 months, seek specialist advice

Question 30

What self care advice should be given for someone with acute diffuse otitis externa?

Answer 30

• To aid recovery and reduce the risk of future infection:
• Avoid damage to the external ear canal - avoid using cotton wool buds or other objects to clean the ear canal
• Keep the ears clean and dry by using ear plugs and or a tight fitting cap when swimming
• People with otitis externa should abstain from water sports for at least 7 to 10 days
• Using a hair dryer (at the lowest setting) to dry the ear canal after hair washing, bathing or swimming
• Keep shampoo, soap and water out of the ear when bathing and showering
• Ensure skin conditions that are associated with the development of otitis externa are well controlled
• Consider using acidifying ear drops or spray (such as Ear Calm) shortly before swimming, after swimming and at bedtime

Question 31

What is earwax?

Answer 31

• A normal physiological substance that protects the ear canal
• Earwax is a combination of sheets of desquamated keratin squames (the dead flattened cells on the outer layers of the skin), cerumen (a wax like substance produced by ceruminous glands which are modified sweat glands), sebum (from sebaceous glands) and various foreign substances (for example cosmetics and dirt)

Question 32

What are the functions of earwax?

Answer 32

• Aids removal of keratin from the ear canal
• Cleans, lubricates and protects the lining of the ear canal, trapping dirt and repelling water, it is mildly acidic and has antibacterial properties

Question 33

How is earwax categorised?

Answer 33

• Wet wax
• Soft wet wax is moist and sticky and the sheets of keratin squames are small, more common in children
• Hard wet wax has a dry, dessicated constituency, and the sheets of keratin are large and dense, it is more common in adults, hard wax is more likely to become impacted
• Dry wax is dry, flaky and golden-yellow and is common in people from Asia

Question 34

What are the risk factors in people for impacted earwax developing?

Answer 34

• Have narrow or deformed ear canals.
• Have numerous hairs in their ear canals — cerumen impaction is more prevalent in older males as they tend to have more hair present in the ear canal.
• Have benign bony growths in the external auditory canal (osteomata).
• Have a dermatological disease of the peri-auricular area or scalp.
• Produce hard or drier wax, as this is more likely to become impacted.
• Are elderly, because as a person ages the cerumen glands atrophy causing the earwax to become drier.
• Have a history of recurrent impacted wax.
• Have learning disabilities — the reason for this is not known.
• Have recurrent otitis externa.
• Have Down’s syndrome — people with Down’s syndrome tend to have small ear canals and dry, scaly wax
• Use of cotton buds as these push the earwax deeper into the canal
• Wear a hearing aid or ear plugs as this prevents the wax being excreted

Question 35

How common is earwax problems?

Answer 35

• Earwax removal is the most common ENT procedure performed in primary care with approximately 4 million ears irrigated annually in the UK

Question 36

What are the complications of earwax?

Answer 36

• Impacted earwax may cause conductive hearing loss - there may be conductive hearing loss of up to 40-50 decibels
• If wax is in contact with the tympanic membrane it may cause discomfort and occasionally vertigo
• Hearing loss due to impacted wax may cause frustration, stress, social isolation, paranoia and depression
• Infection may sometimes occur as a result of wax impaction

Question 37

What is the prognosis of earwax?

Answer 37

• Problems due to earwax often recur

Question 38

How is impacted earwax diagnosed?

Answer 38

• Many people will self diagnose particularly if they have a history of recurrence
• People may also complain of:
• Blocked ears
• Ear discomfort
• Feeling of fullness in the ear
• Earache
• Tinnitus (noises in the ear)
• Itchiness
• Vertigo
• Cough
• May be a history of water exposure as this causes expansion of the earwax and may cause complete blockage of the ear canal
• Children may present with yellow, waxy discharge, this is less common in adults
• Ask about previous removal of impacted earwax, previous tympanic membrane perforation, recurrent or chronic ear problems, hearing aid use and other co-morbidities

Question 39

How should I examine a person with earwax?

Answer 39

• Examine both ears with an otoscope
• Sit at the same level as the person
• Examine the pinna, outer meatus and scalp for signs of previous surgery, discharge, swelling, signs of infection or skin lesions
• Palpate the tragus to assess for pain - if pain is present proceed gently
• Pull the pinna upwards and outwards (downwards and backwards in children) to straighten the external auditory meatus
• Check for foreign bodies, localised infection or inflammation
• Hold the persons head steady and insert the speculum into the meatus
• Note whether wax is present, and whether it appears to be impacted
• Whilst wax occluding the whole meatus may cause hearing loss it is more likely to cause a loss when adherent to the tympanic membrane
• It may not be possible to view the tympanic membrane of wax is present

Question 40

What are the differential diagnoses for impacted earwax?

Answer 40

• Otitis externa
• Foreign bodies
• Keratosis obturans
• Polyp of the ear canal
• Osteoma of the ear canal

Question 41

When should earwax be removed?

Answer 41

• If the earwax is totally occluding the ear canal and any of the following are present:
• Hearing loss
• Earache
• Tinnitus
• Vertigo
• Cough suspected to be due to earwax
• If the tympanic membrane is obscured by wax but needs to be viewed to establish a diagnosis
• If the person wears a hearing aid, wax is present and an impression needs to be taken of the ear canal for a mould, or if wax is causing the hearing aid to whistle

Question 42

How should earwax be removed?

Answer 42

• Explain that removal of earwax may not relieve the symptoms
• Prescribe ear drops for 3-5 days initially to soften wax and aid removal
• Olive oil, or almond oil drops can be used 3-4 times per day for 3-5 days
• Sodium chloride 0.9% is not available as a proprietary ear drop product - off label 0.9% sodium chloride nasal drops can be used in the ear
• Do not prescribe drops if you suspect the person has perforated tympanic membrane
• Warn the person that instilling ear drops may cause transient hearing loss, discomfort, dizziness and irritation of the skin
• If symptoms persist, consider ear irrigation, providing that there are no contraindications
• If ear irrigation is unsuccessful, there are 3 options:
• Advise the person to use ear drops for a further 3-5 days and then return for further irrigation
• Instill water into the ear after 15 minutes irrigate the ear again
• Refer to an ENT specialist for removal of the wax

Question 43

What are the contraindications for ear irrigation?

Answer 43

• Do not use ear irrigation to remove wax for people with:
• Previous problems with irrigation (pain, perforation, severe vertigo)
• Current perforation of the tympanic membrane
• History of perforation of the TM in the last 12 months
• Grommets in place
• History of any ear surgery (except extruded grommets within the last 18 months with subsequent discharge from an ENT department
• Mucus discharge from the ear within the last 12 months
• History of a middle ear infection in the previous 6 weeks
• Cleft palate, whether repaired or not
• Acute otitis externa with an oedematous ear canal and painful pinna
• Presence of a foreign body, including vegetable matter in the ear
• Hearing in only one ear if it is to be treated in that ear
• Confusion or agitation and they may be unable to sit still
• Inability to cooperate, for example young children and some people with learning difficulties
• Use ear irrigation with caution in people with:
• Vertigo, as this may indicate the presence of middle ear disease with perforation of the tympanic membrane
• Recurrent otitis media with or without documented tympanic membrane perforation, as thin scars on the tympanic membrane can easily be perforated
• Immunocompromised state
• Careful instrumentation should be employed in people who are taking anticoagulants due to increased bleeding risk
• Warn people with a history of recurrent otitis externa or tinnitus that ear irrigation may aggravate their symptoms

Question 44

How should ear irrigation be performed?

Answer 44

• Use an electric ear irrigator - should have a variable pressure control so that irrigation can begin at the minimum pressure
• Prepare equipment as per local guidelines and manufacturers instructions - fresh speculum and jet tip for each person
• Ensure the person is sitting comfortably and that you are sitting at the same level - young children should sit on an adults knee with their head held in place, use a good light source, preferably with a head lamp or head mirror throughout the procedure
• Ensure that the temperature of the water used for irrigation is around body temperature
• Pull the pinna upwards and outwards (downwards and backwards for children) to straighten the ear canal
• Angle the jet tip so that the flow of the water is along the top of the posterior wall - compare the perimeter of the canal to a clock face - for the left ear direct the fluid towards 1 o’clock and for the right ear direct the fluid towards 11 o’clock
• Inspect the ear canal periodically with an auriscope to check that the wax had been removed and the tympanic membrane is intact, look for healed perforations, inspect the canal for otitis externa
• Seek immediate advice from an ENT specialist if severe pain, deafness or vertigo occur during or after irrigation or if a perforation is seen following the procedure

Question 45

What are the potential complications of ear irrigation?

Answer 45

• Failure of wax removal
• Otitis externa
• Perforation of the tympanic membrane
• Damage to the external auditory meatus
• Necrotising (malignant) external otitis is a rare infection, occurring primarily in immunocompromised people, especially older people with diabetes mellitus and is often initiated by iatrogenic trauma to the external auditory canal
• Pain
• Vertigo
• Otitis media due to water entering the middle ear when there is a previous perforation
• Exacerbation of pre-existing tinnitus
• Serious injury to the middle and inner ear
• Bleeding
• Nausea, vomiting and vertigo may result from temperature variations of the irrigating fluid

Question 46

When should follow up be arranged for earwax removal?

Answer 46

• Advise anyone who has had earwax removed to return if they develop earache or significant itching of the ear, discharge from the ear (otorrhoea) or swelling of the external auditory meatus, as this may indicate infection

Question 47

What is deafness?

Answer 47

• Disabiling hearing loss refers to hearing loss greater than 40 decibels (dB) in the better hearing ear in adults and a hearing loss greater than 30 dB in the better hearing ear in children (WHO)
• Deaf people mostly have profound hearing loss which implies very little or no hearing - they often use sign language for communication

Question 48

What is hearing loss?

Answer 48

• Thresholds of 25 dB or better in both ears is said to have hearing loss (WHO)

Question 49

What are the preventable causes of childhood hearing loss?

Answer 49

• Infections - mumps, measles, rubella, meningitis, cytomegalovirus infections and chronic otitis media (31%)
• Birth complications such as birth asphyxia, low birth weight, prematurity and jaundice (17%)
• Use of ototoxic medicines in expecting mothers and babies (4%)
• Others (8%)

Question 50

Which strategies can be used to prevent hearing loss?

Answer 50

• Immunising children against childhood diseases, including measles, meningitis, rubella and mumps
• Immunising adolescent girls and women of reproductive age against rubella before pregnancy
• Preventing cytomegalovirus infections in expectant mothers through good hygiene, screen for and treat syphilis and other infections in pregnant women
• Strengthen maternal and child health programmes including promotion of safe child birth
• Follow healthy ear practices
• Reduce exposure (both occupational and recreational) to loud sounds by raising awareness about the risks; developing and enforcing relevant legislation and encouraging individuals to use personal protective devices such as ear plugs and noise cancelling earphones and head phones
• Screening of children for otitis media, followed by appropriate medical or surgical interventions
• Avoiding the use of particular drugs which may be harmful to hearing unless prescribed and monitored by a qualified physician
• Referring infants at high risk such as those with a family history of deafness or those born with low birth weight, birth asphyxia, jaundice or meningitis for early assessment of hearing, to ensure prompt diagnosis and appropriate management as required
• Implimenting the WHO-ITU global standard for personal audio systems and devices (mode 1 standard level for adults derived from 80 dBA for 40 hours per week, mode 2 standard level for sensitive users e.g. children derived from 75 dBA for 40 hours per week)
• Educating young people and population in general on hearing loss, its causes and prevention and identification

Question 51

What are the most common causes of hearing loss?

Answer 51

• Earwax
• Otitis media
• Otitis externa

Question 52

What is presbycusis and how can it lead to deafness?

Answer 52

• Describes age related sensorineural hearing loss
• Patients may describe difficulty following conversations
• Audiometry shows bilateral high frequency hearing loss

Question 53

What is otosclerosis and how can it lead to deafness?

Answer 53

• Autosomal dominant, replacement of normal bone by vascular spongy bone
• Onset is usually at 20-40 years - features include:
• Conductive deafness
• Tinnitus
• Tympanic membrane - 10% of patients may have a ‘flamingo tinge’ caused by hyperaemia
• Positive family history

Question 54

What is glue ear and how can it lead to deafness?

Answer 54

• Also known as otitis media with effusion
• Peaks at 2 years of age
• Hearing loss is usually the presenting feature (glue ear is the commonest cause of conductive hearing loss and elective surgery in childhood)
• Secondary problems such as speech and language delay, behavioural or balance problems may also be seen

Question 55

What is Meniere’s disease and how can it lead to deafness?

Answer 55

• More common in middle aged adults
• Recurrent episodes of vertigo, tinnitus and hearing loss (sensorineural), vertigo is usually the prominent symptom
• Sensation of aural fullness or pressure is now recognised as being common
• Other features include nystagmus and a positive Romberg test
• Episodes last minutes to hours

Question 56

What is ototoxicity and how can it lead to deafness?

Answer 56

• Toxicity to hearing caused by drugs/toxins
• Examples include:
• Gentamicin
• Furosemide
• Aspirin
• Number of cytotoxic agents
• Cisplatin
• Venk-alkaloid

Question 57

How can noise damage lead to deafness?

Answer 57

• Workers in heavy industry are particularly at risk

* Hearing loss is bilateral and typically is worse at frequencies of 3000-6000 Hz

Question 58

What is an acoustic neuroma (more correctly called vestibular schwannomas) and how can it lead to deafness?

Answer 58

• Features can be predicted by the affected cranial nerves
• CN VIII - hearing loss, vertigo, tinnitus
• CN V - absent corneal reflex
• CN VII - facial palsy
• Bilateral acoustic neuromas are seen in neurofibromatosis type 2

Question 59

How is hearing loss categorised?

Answer 59

• Conductive
• Sensorineural
• Mixed

Question 60

What is conductive hearing loss?

Answer 60

• Occurs due to abnormalities of the outer or middle ear which impair conduction of sound waves from the external ear (pinna, ear canal or tympanic membrane) through the ossicles (malleus, incurs and stapes) in the middle ear to the cochlea in the inner ear

Question 61

What is sensorineural hearing loss?

Answer 61

• Occurs due to abnormalities in the cochlea, auditory nerve or other structures in the neural pathway leading from the inner ear to the auditory cortex

Question 62

What is mixed hearing loss?

Answer 62

• Occurs when abnormalities causing both conductive and sensorineural hearing loss are present

Question 63

How is hearing loss categorised?

Answer 63

• Mild (25-39 dB)
• Moderate (40-69 dB)
• Severe (70-94 dB)
• Profound (>95 dB)

Based on the quietest sound that can be heard measured in decibels (dB HL (decibel hearing level) on pure tone audiometry).

Question 64

What are the causes of conductive hearing loss?

Answer 64

• Impacted earwax (cerumen)
• Foreign bodies
• Tympanic membrane perforation
• Infection
• Cholesteatoma
• Middle ear effusion
• Otoslerosis - abnormal bony growth affecting the small bones of the ear (mainly the stapes)
• Neoplasm - SCC of the external ear and vascular glomus tumour behind the eardrum
• Exostoses - hard bony growths in the ear canal (associated with swimming in cold water)

Question 65

What are the causes of sensorineural hearing loss?

Answer 65

• Age related hearing loss (presbycusis) - most common
• Noise exposure
• Sudden sensorineural hearing loss (SSHL)
• Defined as sudden onset (within 72 hours) hearing loss of 30 dB HL or more which involves 3 frequencies and cannot be explained by outer or middle ear conditions
• In 90% of cases no underlying cause is identified and SSNHL is considered to be idiopathic
• Hearing loss can range from mild to profound and may be temporary or permanent
• Meniere’s disease
• Exposure to ototoxic substances - aminoglycosides, loop diuretics, NSAIDS, aspirin, anti-malarials (quinine and chloroquine) and cytotoxic drugs (cisplatin and bleomycin), pesticides, cigarette smoke and heavy metals e.g. mercury and lead
• Labyrinthitis
• Vestibular schwannoma (aka acoustic neuroma) - benign tumour causing hearing loss via compression of the cochlear nerve - may in some cases grow into the posterior cranial fossa and cause brain stem compression
• Neurological conditions such as MS or stroke
• Malignancy including nasopharyngeal cancer and intracranial tumours
• Trauma to the head or ear
• Systemic infections - CMV, toxoplasmosis, syphilis, meningitis, HIV measles, Lyme disease, herpes zoster, (Ramsay-Hunt syndrome)
• Autoimmune conditions such as RA, SLE, sarcoidosis, Wegners granuloma and auto immune inner ear disease
• Hereditary conditions such as Alports syndrome (genetic condition associated with progressive renal impairment and hearing loss)

Question 66

What is the prognosis of conductive hearing loss?

Answer 66

• Many can be treated with full return to usual hearing (for example uncomplicated infections of the outer or middle ear and wax impaction)
• Some causes of conductive hearing loss such as necrotising otitis externa can be life threatening if not identified and treated early

Question 67

What is the prognosis of sensorineural hearing loss?

Answer 67

• Hearing loss associated with age and excessive noise is usually slowly progressive and permanent
• Sudden sensorineural hearing loss has a variable prognosis - early intervention with steroids is the mainstay of treatment

Question 68

What are the adverse affects of hearing loss?

Answer 68

Can adversely affect:

• Relationships with family and friends due to communication difficulties
• Social engagement and participation in leisure activities which may lead to social withdrawal, isolation and loneliness
• Risk of unemployment and lower income
• Reduced quality of life and ability to function independently
• Increased risk of developing depression and anxiety

Question 69

Which questions are important to ask regarding the history of a patient with hearing loss?

Answer 69

• Onset and progression - sudden (over 72 hours), rapidly progressive (within 90 days), slowly progressive or fluctuating
• Bilateral or unilateral
• Associated features:
• Tinnitus
• Vertigo
• Otorrhoea (discharge) or otalgia (ear pain)
• Sensation of fullness or pressure in the ear
• Head/neck trauma, pain or swelling
• Neurological symptoms
• Past medical history
• Previous chronic ear infections or hearing loss
• ENT surgery of head trauma
• Exposure to noise (including occupational)
• Chronic disease
• Medication including use of ototoxic drugs
• Occupation including exposure to environmental toxins
• Family history of hearing loss
• Impact of hearing loss on communication, relationships, function (at home, in work/education and socially) quality of life and mood

Question 70

How should a person with hearing loss be examined?

Answer 70

• The pinna and surrounding skin looking for signs of inflammation, infection or abnormal lesions.
• The ear canal and tympanic membrane (using an otoscope) to identify clinical features suggestive of conductive hearing loss.
• If full visualisation is not possible due to earwax arrange wax removal and review to reassess.
• Weber and Rinne tuning fork tests to help distinguish between conductive and sensorineural hearing loss.
• Cranial nerves and cerebellar function to exclude focal neurology.
• The head and neck for lymphadenopathy or other masses.
• For clinical features of underlying systemic causes such as infective, autoimmune, metabolic or neurological conditions

Question 71

How is the turning fork test performed?

Answer 71

• Hold a 512 Hz tuning fork by its stem and strike one side (two thirds of the way from the base) on a padded surface or the ball of the hand

For the Weber test

• Place the vibrating tuning fork on the person’s forehead (alternatively it can be placed on the vertex, bridge of the nose or chin) and hold in place for up to 4 seconds.
• Ask the person where the tone is heard — in both ears, centrally, in the head or towards the left or right. If sound is heard:
• Centrally this suggests symmetrical hearing or a symmetrical hearing loss.
• In the poorer/affected ear this suggests an asymmetrical conductive hearing loss.
• In the better/unaffected ear this suggests an asymmetrical sensorineural hearing loss.
• The Weber test can be complicated by the presence of a unilateral or asymmetrical conductive hearing loss, where the tone can be heard on the conductive side or the side with the greater conductive loss

For the Rinne test

• Start with the ear that the Weber test lateralised to (if applicable).
• Hold the vibrating tuning fork approximately 25mm from the entrance to the ear canal for about 2 seconds then without touching the tines press the footplate of the tuning fork firmly over the mastoid and hold the tuning fork in place for 2 seconds.
• Ask the person if the tone is louder next to the ear or behind the ear. If sound is heard:
• Better/louder by air conduction (next to the ear canal) this is ‘Rinne positive’ suggestive of a sensorineural hearing loss or normal hearing.
• Better/louder by bone conduction (held on the mastoid) this is ‘Rinne negative’ suggestive of conductive hearing loss in that ear

Question 72

What are the potential differential diagnoses for hearing loss?

Answer 72

• Dementia

* Depression

Question 73

When should a person with hearing loss be referred to secondary care urgently for assessment within 24 hours by ENT or an emergency department?

Answer 73

• Sudden onset (over 3 days or less) unilateral or bilateral hearing loss which has occurred within the past 30 days and cannot be explained by external or middle ear causes
• Unilateral hearing loss associated with focal neurology such as altered sensation or facial droop - if stroke is suspected follow the stroke referral pathway
• Hearing loss associated with head or neck injury
• Hearing loss associated with severe infection such as necrotising otitis externa or Ramsay Hunt
• Otalgia and otorrhoea that has not responded to treatment within 72 hours in a person who is immuno-compromised is suggestive of necrotising otitis externa

Question 74

When should a person with hearing loss be referred to secondary care urgently for assessment within 2 weeks by ENT or an emergency department?

Answer 74

• Sudden onset over 3 days
• Rapidly progressive hearing loss over 4-90 days
• Suspected head and neck malignancy

Question 75

How should a person with hearing loss be managed in primary care?

Answer 75

• If the person presents for the first time with hearing loss and there are no indications for referral to ENT or the emergency department
• Exclude or treat the causes of hearing loss such as impacted wax, acute ear infection and middle ear effusion due to acute upper respiratory tract infection
• Discuss with/refer to ENT if after initial treatment for earwax or acute infection:
• Eardrum cannot be examined because of partial or complete obstruction of ear canal
• Pain in or around the ear persists for more than one week and has not responded to first line treatment
• Discharge from either ear has not resolved with treatment or is recurrent
• Abnormalities of the outer ear or eardrum are visible
• Middle ear effusion which is not associated with or persists after upper respiratory tract infection is suspected
• Arrange for audiology assessment:
• If sensorineural hearing loss is confirmed and no underlying cause suspected, hearing aids will be considered
• If hearing aids are fitted, face to face follow up (after 6-12 weeks) should be arranged by audiology
• Bilateral hearing aids should be offered to people with aidable hearing loss in both ears as this can improve sound quality and make speech easier ti understand against background noise
• Provide information and support

Question 76

How to hearing aids work?

Answer 76

• Consist of a microphone, a battery powered amplifier, a receiver and a means to route amplified sound into the ear canal
• As hearing aids cannot improve deficits in frequency, temporal and spatial resolution (which are often associated with age related and noise induced hearing loss) the person may continue to have some hearing difficulties, even when wearing hearing aids
• Use of bilateral hearing aids improves intelligibility of speech in background noise, sound localisation and sound quality
• If only one hearing aid is used over time, deficits may develop in the unaided ear due to reduced stimulation in that ear

Question 77

What are active listening devices?

Answer 77

• ALD’s can improve hearing in situations with background noise by amplifying sound from a specific source such as a person speaking or a television and sending it straight to the ears
• Other ALD’s such as doorbell sensors, baby alarms and smoke detectors alert the person to environmental sounds through flashing lights, vibration or loud sounds

Question 78

What are implantable devices?

Answer 78

• Such as cochlear implants or bone conducting hearing implants may be appropriate for people whose sensorineural hearing loss is too severe for hearing aids - these require referral to ENT for surgical intervention

Question 79

What is (viral) labyrinthitis?

Answer 79

• Inflammatory disorder of the membranous labyrinth, affecting both the vestibular and cochlear end organs
• Labyrinthitis can be viral, bacterial or associated with systemic diseases
• Viral labyrinthitis is the most common form of labyrinthitis

Question 80

What is the difference between labyrinthitis and vestibular neuritis?

Answer 80

• Vestibular neuritis is used to define cases in which only the vestibular nerve is involved, hence there is no hearing impairment
• Labyrinthitis is used when both vestibular nerve and the labyrinth are involved, usually resulting in both vertigo and hearing impairment

Question 81

What age is labyrinthitis more common in?

Answer 81

• 40-70 years

Question 82

How do patients with labyrinthitis typically present?

Answer 82

• Acute onset of:
• Vertigo - not triggered by movement but exacerbated by movement
• Nausea and vomiting
• Hearing loss - may be unilateral or bilateral, with varying severity
• Tinnitus
• Preceding or concurrent symptoms of upper respiratory tract infection

Question 83

What are the signs of labyrinthitis?

Answer 83

• Spontaneous unidirectional horizontal nystagmus towards the unaffected side
• Sensorineural hearing loss - shown by Rinnes and Webers test
• Abnormal head impulse test signifies an impaired vestibulo-cular reflex
• Gait disturbance - patient may fall towards the affected side
• Normal skew test
• Abnormality on inspection of the external ear canal and the tympanic membrane e.g. vesicles in herpes simplex infection

Question 84

What investigations can be done for labyrinthitis?

Answer 84

• Diagnosis is largely based on history and examination
• Glucose is helpful in excluding hypoglycaemia
• In most patients with suspected viral labyrinthitis, no other investigation is necessary

Question 85

What investigations can be considered if the diagnosis of labyrinthitis is unclear?

Answer 85

• Pure tone audiometry can be done to assess hearing loss
• FBC and blood culture if systemic infection is suspected
• Culture and sensitivity testing if any middle ear effusion
• Temporal bone CT scan - indicated if suspecting mastoiditis or cholesteatoma
• MRI scan - helpful to rule out causes such as suppurative labyrinthitis or central causes of vertigo
• Vestibular function testing may be helpful in difficult cases and/or determining prognosis