Otitis Flashcards

1
Q

Describe the follicle type found in ears

A

In all but Cockers are simple follicles, Cockers hve complex follicles

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2
Q

Name the portions of the tympanic membrane

A
  • Pars flaccida

- Pars tensa

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3
Q

Name and define the types of ear disease that are possible

A
  • Pinnal disease: diseases affecting the ear flap
  • Otitis externa: inflammation of the outer ear
  • Otitis media: inflammation of the middle ear
  • Otitis interna: inflammation of the inner ear
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4
Q

What is pinnal disease typically a reflection of?

A

Otitis externa

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5
Q

Name the pruritic conditions that may affect the pinnal margins

A
  • Scabies
  • Neotrombiculosis
  • Rarely atopy
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6
Q

Name the non-pruritic diseases that may affect the pinnal margins

A
  • Vasculitis
  • Pinnal margin seborrhoea
  • Squamous cell carcinoma
  • Actinic dermatosis
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7
Q

Name the pruritic diseases that typically affect the pinnal surface

A
  • Atopic dermatitis
  • Food allergy
  • pemphigu foliaceous
  • Fleas (cats)
  • Contact irritant dermatitis
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8
Q

Name the non-pruritic diseases that typically affect the pinnal suface

A
  • Pemphigus foliaceous
  • Alopeciea in HAC or hypoT
  • Contact irritant dermatitis
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9
Q

Name the pruritic diseases that typically affect the pinnal body

A

Aural haematoma

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10
Q

Name the non-pruritic diseases that typically affect the pinnal body

A

Auricular chondritis

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11
Q

Which breed is predisposed to ear amrgin seborrhoea?

A

Dachshunds

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12
Q

Describe the appearance of ear margin seborrhoea

A
  • Adherent keratin on both sides of pinna lumpy, thickened area of scale felt around the edge, removal leads to ulceration
  • Follicular casts and plugs may trap hair
  • Rubbing produces ulcerations and erosions
  • Fissuring and secondary infection can occur
  • Pruritus variable
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13
Q

What condition can ear margin seborrhoea occur secondary to?

A

Hypothyroidism

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14
Q

What are the differential diagnoses for ear margin seborrhoea?

A
  • Early vasculitis
  • Early localised scabies
  • Many other seborrhoeic conditions if widespread
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15
Q

Describe the appearance of pinnal margin vasculitis

A

Notch in the end of the ear

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16
Q

Describe the treatment for ear margin seborrhoea

A
  • Emolient rinses, vaseline, propylene glycol

- Surgery to trim end of ear off, will not be recognisable once hair regrows

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17
Q

Describe the normal physiology of the ear

A
  • Temp: 28.2-28.4degreesC
  • 88.5% humidity
  • pH 6.1-6.2
  • Sebaceous and ceruminous glands present
  • Cerumen present
  • Normal flora
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18
Q

What is cerumen made up of?

A

LIpids and sloughed keratinocytes

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19
Q

Describe the function of cerumen

A
  • Traps small foreign bodies
  • Anti-bacterial, anti-yeast properties
  • Removal of pathogens and foreign bodies via epithelial migration from tympanic membrane to the external space
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20
Q

What factors disturb epithelial migration?

A
  • Inflammation
  • Wetness
  • Hyperplasia
  • Physical blockage
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21
Q

Describe the normal flora of the ear canal

A
  • Gram +ve cocci predominate
  • Some dogs have no growth
  • Similar to those found on skin e.g.
  • Micrococcus spp.
  • Coagulase negative staphylococci: Staph. schleiferi, pseudintermedius, aureus
  • Streptococcus spp.
  • Malassezia
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22
Q

What is the most important factor in otic disease?

A

Humidity - changes epithelial defences, microbiological proliferation, treatment

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23
Q

Identify the broad groups of causes of otitis externa

A
  • Predisposing causes
  • Primary causes
  • Secondary disease
  • Perpetuating factors
  • Disease progression
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24
Q

List the predisposing causes of otitis externa

A
  • Conformation
  • excessive moisture
  • Obstructive ear disease
  • Primary otitis media
  • Treatment effects
  • General immunosuppression due to catabolic states, debilitation etc.
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25
Q

Give examples of how conformation can be a predisposing cause of otitis externa

A
  • Excessive hair growth in canals (e.g. poodle) leads to wax accumulation and secondary infection
  • Hair concave pinnae e.g. Cocker, produce occlusive blanket around head
  • Pendulous pinnae e.g. Bassett hound, long canal and long pinna covering it increases humidity
  • Stenotic canals e.g. Shar Pei
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26
Q

Explain how excessive moisture in the ear may occur

A
  • Environment (head and humidity)

- Water (Swimmer’s ear, grooming, cleaners)

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27
Q

Give examples of how obstructive ear disease may occur as a predisposing cause of otitis externa

A
  • Feline apocrine cystadenomatosis (common old cat problem)
  • Neoplasia
  • Polyps
  • Wax blockage
  • Trauma e.g. bite across canal
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28
Q

Give examples of how primary otitis media can be a predisposing cause otitis externa

A
  • Primary secretory otitis media (PSOM) in CKCS
  • Tumour
  • Sepsis
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29
Q

Give examples of how treatment effects can be predisposing causes for otitis externa

A
  • Altered microflora e.g. inappropriate cleaner

- Trauma from cleaning or plucking

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30
Q

List primary causes of otitis externa

A
  • Parasites
  • Foreign bodies
  • Hypersensitivity
  • Keratinisation disorders
  • Glandular disorders
  • Miscellaneous
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31
Q

Identify parasites that may act as a primary cause for otitis externa

A
  • Otodectes cynotis common cause
  • Demodex
  • Scabies
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32
Q

Describe the treatment of Otodectes cynotis

A
  • Most ear creams are effective with localised disease: Selamectin or moxidectin spot on enough for single cat
  • May also need cleaner +/- steroids
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33
Q

Give an example of a very common foreign body that can act as a primary cause of otitis externa

A

Grass seeds

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34
Q

Give examples of hypersensitivities that may act as primary causes of otitis externa

A
  • Atopic dermatitis
  • Food hypersensitivity
  • Medications
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35
Q

Discuss the importance of otitis externa as a complication of hypersensitivity

A
  • Common complication of AD and CAFR
  • Primary otitis often not recognised and inadequately treated
  • Presented when there is secondary infection
  • Recurrence common before hypersensitivity is recognised
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36
Q

Give examples of keratinisation disorders that may act as primary causes of otitis externa

A
  • Primary idiopathic seborrhoea

- Hypothyroidism

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37
Q

Explain how glandular disorders can act as primary causes of otitis externa

A

Cockers, English Springers and Labrador retrievers have increased ceruminous glands so produce lots of wax, can be difficult to remove and lead to accumulation of debris/pathogens adn cause inflammation

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38
Q

Give an example of a primary cause of otitis externa in kittens

A

Feline proliferative and nectrotising otitis externa

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39
Q

Identify the secondary diseases that can cause otitis externa

A
  • Bacteria
  • Yeast
  • Fungi
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40
Q

Compare acute and chronic bacterial disease as secondary disease causing otitis external

A
  • Acute: Gram +ve bacteria e.g. Staph spp. Strep spp. Corynebacerium spp.
  • Chronic disease: iterventions contribute to changes in ear flora. Gram +ve e.g. Enterococcus, and Gram -ve e.g. Pseudomonas spp, Proteus spp, Eschericia coli spp.
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41
Q

Describe yeast infections as a secondary disease that can cause otitis externa

A
  • Malassezia common
  • Hypersensitivity component, can mean some yeasts are very inflammatory in the ear
  • Lipid dependent Malassezia also
  • Candida spp. also (uncommon)
42
Q

Give an example of a fungal infection that can act as a secondary disease leading to otitis externa

A

Aspergillus spp, very uncommon

43
Q

List perpetuating factors in otitis externa

A
  • Pathological changes in external ear canal
  • e.g. changes in canal wall
  • Changes in glandular tissue
  • Changes in tympanum
  • Otitis media
44
Q

Describe pathological changes (acute and chronic) in the canal wall as a perpetuating factor in otitis externa

A
  • Inflammation causing failure of epithelial migration
  • Acute change: oedema, hyperplasia
  • Chronic change: proliferative change, canal stenosis, calcification of pericartiaginous fibrous tissue
45
Q

Explain how pathological changes of the glandular tissue in the external ear can act as perpetuating factors for otitis externa

A
  • Hyperplasia of ceruminous and sebaceous glands, hidradenitis
  • Produce more watery substance in ear, will not reduce bacterial numbers
  • Then will become more cellular and diverted emulsion - sticky, wet wax with neutrophils = pus
46
Q

What is hidradenitis?

A

Inflammation around ceruminous glands/sweat glands

47
Q

Describe pathological change in the tympanum that can act as perpetuating factors for otitis externa

A
  • Dilation, rupture, diverticulum formation
  • Diverticulum is false middle ear, cholesteatoma can form inside which balls up and becomes destructive to the containing part of the ear, grows gradually and can cause erosions, Can push M back so far that it appears to be missing
48
Q

Explain how otitis media (acute and chronic) can act as a perpetuating factor for otitis externa

A
  • Acute: foreign material, mucopurulent exudate

- Chronic: biofilm formation, granulation material, bony change in the bulla

49
Q

Outline the disease progression of otitis externa

A
  • Secondary disease follows primary cause
  • In many dogs and cats, Malassezia -> Staph. -> gram -ve rods
  • In many cases, Pseudomonas aeruginosa is endpoint if treatment inadequate
50
Q

List the progressive pathological changes that occur as a consequence of otitis externa over time

A
  • Epidermal hyperkeratosis and hyperplasia
  • Dermal oedema
  • Fibrosis
  • Ceruminal gland hyperplasia and dilation (sebaceous glands neither proliferate nor produce secretions)
  • Abnormal epithelial cell migration
  • Tympanic membrane alterations
  • Otitis media
51
Q

Give a rough idea of the proportion of acute and chronic otitis externa that progress to otitis media

A
  • 16% of acute

- 50-80% of chronic

52
Q

List the potential consequences of otitis media

A
  • Conductive deafness
  • Horner’s syndrome
  • Vestibular syndrome
53
Q

Describe the development of conductive deafness from otitis externa ormedia

A
  • Loss of drug
  • High pressure fluid/mucous in ear
  • Chronic OE or OM +/- cholesteatoma
54
Q

Describe the clinical signs of Horner’s syndrome

A
  • Ear and lip droop
  • Keratoconjunctivitis sicca, neurogenic dry nose
  • Anisocoria with ipsilateral muosis, ptosis of upper eyelid
  • Enophthalmos of affect side
  • Conjunctival hyperaemia on affected side
55
Q

Describe the classical presentation for Primary Secretory Otitis Media in the CKCS

A
  • Presented for deafness or neck pain
  • Marked mucoid build up in middle ear
  • Bulging middle ear noted on otoscopy, very obvious
  • May see neurological signs: ataxia, facial paralysis, nystagmus, head tilt, seizures
  • May see pruritus around th ears without OE
  • OE of varying degrees
  • Fatigue
56
Q

How is Primary Secretory Otitis Media treated?

A
  • Make hole in drum followed by repeated flushing and myringotomy (3-5 times)
  • Sputolysin (mucolytic) used by some
  • Steroids used to reduce mucous production
57
Q

How may otitis interna develop?

A
  • Extension of OM (majority)
  • Haematogenous and ascending infection via the auditory tube
  • Systemic infection
58
Q

Describe the clinical signs of otitis interna

A
  • Head tilt to affected side
  • Spontaneous or rotary nystagmus
  • Asymmetrical limb ataxia with preservation of strength
  • Falling
  • Vomiting and anorexia
59
Q

Describe the 2 main presentations of otitis externa

A

1: Lichenified, pruritic ear, common for alopecia and erythema to come onto cranial side of ear flap
2: Ceruminous otitis, may show less on pinna and meatus

60
Q

Describe the clinical signs of otitis externa

A
  • Aural pruritus or head shaking
  • Mild to marked exudate
  • Malodour
  • Head tilt
  • Deafness
61
Q

Describe the common physical findings in otitis externa

A
  • Erythema, swelling, scaling, discharge (otorrhoea), malodour, pain
  • Secondary changes: pinnal lesions due to pruritus, pyotraumatic dermatitis elsewhere on head/face (miss ear when scratch), haematoma ue to head shaking/trauma from scratching
62
Q

Describe the clinical signs of otitis media

A
  • Variable, often non-specific e.g. pain, inappetance
  • MOst often signs of concurrent OE are most obvious
  • Deafness
  • Pain on eating
  • Signs of otitis interna if progressing
63
Q

Outline the investigation of otitis media

A
  • Examine appearance of drum on otoscopy (may require flushing)
  • Sampling of middle ear for bacteriology, fungal culture and cytology (myringotomy or ruptured TM)
  • Palpation of granulation tissue in middle ear
  • BAER hearing test
  • Imaging (radiography, CT, MRI)
64
Q

Compare the normal findings on palpation of granulation tissue in the middle ear, with that of an ear with otitis media

A

Use probe with slight bend (and only in larger dogs) - should normally hear a tap, rather than a spongy sound

65
Q

Why is the BAER hearing test used in the investigation of otitis media? Give the full name

A
  • Brainstem auditory evoked response

- Can assess delay in conduction and differentiate conductive from central deafness

66
Q

Evaluate the role of radiography in the investigation of otitis media

A
  • Insensitive assessment of OM
  • Obvious changes only with severe disease
  • May see thickening of wall of bulla in chronic disease
  • Changes absent in many cases of OM
67
Q

When using radiography in the investigation of otitis media, which views are taken?

A

Lateral oblique and open mouth views

68
Q

Evaluate the use of MRI or CT in the investigation of otitis media

A
  • MRI much better appreciation of soft tissue structures

- CT can be useful cheaper alternative in many cases

69
Q

What is myringotomy?

A

Surgical incision into the ear drum, often to relieve presure

70
Q

List the infication for myringotomy

A
  • Bulging TM with pain or neurological signs
  • Tympanosclerosis (as an exploratory mryingotomy)
  • Radiographic MRI shows bulla changes and intact TM
  • Evidence of tissue or fluid behind the TM
  • Medially unresponsive vestibular disease with an intact TM
  • Chronic otitis cases longer than 6 months that have not responded to treatment for OE
71
Q

Briefly outline the method for myringotomy

A
  • Clean and dry external ear canal
  • Incision using 5-Frensh polypropylene catheter, Tomcat catheter or small wire swab
  • Pass through otoscope
  • Position on caudoventral aspect of pars tensa to avoid damaging tympanic germinal epithelium and the structure of the middle ear
  • Pass swabs, instill then withdraw small amount of sterile saline solution
  • Flush with saline +/- other agents depending on cytology
72
Q

List the differential diagnoses for otitis interna

A
  • Other peripheral vestibular disease
  • Idiopathic vestibular syndrome
  • Neoplasia (vestibulocochlear nerve)
  • Hypothyroidism
73
Q

Outline the method of diagnosis of otitis interna

A
  • Establish presence of systemic disease and/or localised disease (OE/OM)
  • Pruritus, headshaking and pain around TMJ are useful indicators of local disease
  • Complete neuro exaM
  • Otic examination +/- myringotomy
  • MRI, possibly CT
74
Q

Outline the key points in the treatment of otitis externa

A
  • Need to treat primary and secondary disease, predisposing factors and perpetuating factors
  • Ensure owner knows how to intervene early
  • Ensure no debris preventing penetration of treatment
75
Q

Outline the treatment of otitis interna

A
  • In absence of another cause, long term use of systemic antibiotics advocated
  • Based on culture of middle ear
76
Q

Describe the antibiotic, antifungal and steroid properties of Osurnia (florifenicol) ear treatment

A
  • Bacteriostatic antibiotic, inhibits protein synthesis, active vs Gram +ve and -ve
  • Active vs Staph. pseudintermedius
  • Terbinafine: active against Malassezia
  • Beta-methaasone acetate: GC absorbed systemically in first 2-4 days
77
Q

Describe the antibiotic, antigfungal and steroid properties of Aurizon ear treatment

A
  • Marbofloxacin, clotrimazole, dexamethasone
  • Marbo: active vs G+ve bacteria, G-ve bacteria
  • Clotrimazole broad spec
  • Dex: absorption over 14 days
78
Q

Describe the antibiotic, antifungal and steroid properties of Posatex ear treatment

A
  • Orbifloxacin: broad spec, active G+ve and G-ve
  • Mometasone furoate glucocorticoid, minial absorption
  • Posaconazole, active against Malassezia
79
Q

Describe the antibiotic, antifungal, anti-ectoparasitic and steroid properties of Surolan ear treatment

A
  • Polymyxin B: bactericidal, active against G-ve incl. Pseudomonas aeruginosa and E. coli
  • Miconazole nitrate: active against trichophyton, Microsporum, Malassezia, Candida
  • Active against Otodectes cynotis
  • Systemic absorptoin of prednisolone
80
Q

Describe the antibiotic, antifungal and steroid properties of Easotic/Otomax ear treatment, plus additional information

A
  • Gentamicin: mostly G-ve incl Pseudomonas, E coli, and G+ve Staph pseudintermedius
  • Hydrocortisone aceponate: short acting, low potency
  • Gentamicin is ototoxic so not for performated ear drums
  • Easotic contains miconazole nitrate, otomax contains clotrimazole
81
Q

Describe the antibiotic, antifungal and steroid properties of Canaural ear treatment

A
  • Fusidic acid (diethanolamine fusidate salt): high activity vs Staph
  • Framycetin sulphate broad spec. antibiotic, active against G-ve
  • Prednisolone glucocorticoid, systemic absorption
  • Contains nysatin antifungal
82
Q

What specific ear history points are important in the investigation o otitis externa or media?

A
  • Unilateral or bilateral?
  • Pruritus/head shaking/scratching
  • Smell
  • Head tilt
  • Signs of facial paralysis
83
Q

What should you look out for in particular during the clinical examination of an animal presented for ear disease?

A
  • Other skin disease
  • Neurological problems
  • Ear carriage
  • Pinna and outer meatus and upper vertical canal
  • Smell
84
Q

What might be required prior to otoscopy of a diseased ear?

A
  • Treat for short period with corticosteroids, then reassess

- Or chemical restraint if emergency e.g. grass seed suspected

85
Q

What should be considered during examination of the ear canal?

A
  • Surface of the epithelium: smooth? Papillarae? Cystic bumps?
  • Surface of canal: red? Inflamed? Pus?
  • Lumen: open and consistently so? Size of lumen?
  • Nature of discharge
  • Eptihelial migration demonstrated by wax spread up and coming towards opening in a discrete way
86
Q

Describe changes that may be observed on the tympanic membrane with otic disease

A
  • Present or absent?
  • Ruptured or pushed back
  • Changes in colour
  • Bulging
87
Q

What pathogen is often associated with otic discharge similar to dry coffee grounds?

A

Otodectes cynotis

88
Q

What pathogens are often associated with moist brown exudate otic discharge?

A

Staphylococcus spp. , Malassezia

89
Q

Describe the type of otic discharge commonly associated with Gram-ve bacteria, especially Pseudomonas spp.

A

Purulent yellow/green exudates (malodorous), can also be tarry black. Biofilm produced, feels like snot

90
Q

What underlying cause is ceruminous discharge with little smell often indicative of?

A
  • Allergy
  • Endocrine (esp, hypoT)
  • Keratinisation defects
  • Bacteroides spp.
91
Q

Outline the importanve of wax and cytology examination in the investigation of otic disease

A
  • Usually possible even when otoscopy is not
  • Best to perform in all cases
  • Affected by treatments which are often oily
  • Good to have baseline
  • Swabs kept in charcoal for reference
  • Consider taking bacteriology swab with cytology then submit, store or dispose
92
Q

Describe the staining of otic wax samples

A
  • Poor stickiness so use staining rack

- Apply methylene blue only and a coverslip (stain 3 of DiffQuik)

93
Q

Describe the staining of purulent otic wax samples

A
  • Stain as for cytology

- For eosinophilic staining use last 2 stains of DiffQuik alone, squeeze out excess using coverslip

94
Q

Give examples of factors that may prevent sampling of a representative population from an ear

A
  • Wax or cream blockage can prevent swab getting deeper into the ear to sample the true population of pathogens causing disease
  • If ear drum heals over, cannot sample middle ear for the true population causing disease
95
Q

Discuss the advantages and disadvantages of bacteriology in the investigation of otic disease

A
  • Confirms and/or identifies bacteria present in ear canal
  • Presence of bacteria does not equal disease
  • Common affected by previous antibiotic ear creams and previous cleaners
  • Provides susceptibility data, but flawed when considering topical treatment
96
Q

Explain why MIC data is not reliable when considering ear treatments

A
  • MIC data relates to oral or parenteral antibiotics
  • Much higher doses reach ear when used topically, so MIC achieved more easily in area where it is needed
  • Bacteria likely to be susceptible to higher doses so cannot reply on MIC
97
Q

Explain the diagnostic value of flushing the ears

A
  • See epithelium of ear canal more clearly and assess for hyperplasia, ulceration, masses and defects
  • Check integrity of the drum, very difficult to assess correct level of drum in many dogs
98
Q

Explain the therapeutic value of flushing the ears

A
  • Dilutes and removes bacteria, yeasts and inflamm. mediators
  • If add appropriate cleaners has anti-microbial effects
  • Removes pus which may inactivate antibiotics
  • Removes old treatments
  • Removal of debris which can act as a nidus for infection
99
Q

List the otic flushing solutions that are available

A
  • Normal saline
  • Dilute povidone iodine
  • Chlorhexidine
  • Others: cerumolytics, aqueous solutions, drying agents
100
Q

Which of the flushing solutions are safest?

A

Saline and TRIZChlor