Diseases Of The Ear Flashcards
Otitis externa - definition and occurance
- Acute or chronic inflammation of the external ear canal
- Prevalence: 15-20% (dogs), 6-7% (cats)
- Affects one third of patients
What is the etiology of otitis externa?
- I. Primary factors
- II. Secondary factors
- III. Predisposing factors
- IV. Perpetuating factors
Primary factors
Diseases that cause OE directly, such as:
(90% due to allergy - skin covered tube!!)
• Atopy
• Food allergy
• Contact - hypersensitivity
• Parasites (otodectes, demodex, sarcoptes, etc)
• Foreign Bodies
• Disorders of keratinization
• Autoimmune disorders
• Endocrine disorders (hypothyroidisim)
• Tumors
Secundary factors
Do not cause problems in a healthy ear, but can cause problems in case of primary/predisposing factors (eg. Inflammation turn purulent)
• Bacteria
• Yeasts
• Irritative substances
• Overcleaning
–> Only treating these wont cure if underlying condition helping the overgrowth
Predisposing factors
Factors that alter the externa ear canal, thus make it susceptible for OE - preventing self cleaning!
• Pendulous/naturally narrowed (chow chow, pug) auditory canal
• Frequent bathing, swimming (humid - infection)
• Increased soft tissue content (glandular hyperplasia)
• Increased amount of hair within the ear canal (Blocking epith migration, incr temp)
Perpetuating factors
Consequences of OE that maintain inflammation - must treat to as they maintain!!!
• Skin edema, fibrosis (diameter)
• Reduced epithelial migration (Ear cells act like threadmill slowly tp everything outwards, If not poroper - debris build up)
• Ulceration, thickened skin
• Ceruminous gland dilatation and obstruction • Stricture
• Otitis Media (OM) (Eg pseudomonas migrate through tymp memb -> colonize in middle ear. Can also travel outwards)
What are the most important diagnostic steps of otitis externa?
For successful treatment all must be fullfilled!!!
• First: Precise diagnosis
• Signalment + History -> Primary and predisposing
factors (food, localization of scratching - systemic derm?, FB, other animal, behaviour)
•Thorough otoscope examination of the external ear canal to evaluate six key points (see on next card)
•Additional examinations to uncover actual problems (cytology!!!!, microbiology, histopathology)
What are the 6 points you have to assess during the otoscopic examination?
- Skin of concave surface of the pinna
- Width and length of ear canal
- Amount and quality of discharge
- Skin of ear canal
- Sensitivity and palpation of the ear canal (nonsensitive terrible looking irreversible, resection?)
- State of tympanic membrane (Obscured by hair, discharge etc
Good way to check intactness wo visualization - fill with water, no bubbles/leaking = Intact!)
Why is cleaning so important?
• Important to evaluate some of the former parameters
• Very useful in treatment (incr surface area for medication to work)
• First thing after/during examination of
the ear canal
• Client education (do it in front of owner!)
How do you clean?
•If a thorough cleaning is not possible without it, sedation is necessary - must schedule later appointment
•Mechanical cleaning -> Warm (lukewarm) saline infusion, tapwater in great quantities until all content is removed
- (cold touch TM -> caloric? Effect -> ataxia etc suddenly, traumatic for owner)
- avoid eyes!
- mostly work of the owner, regularily! (Weekly eg, all depending)
What do you use for cleaning when water/saline isnt enough?
- Cerumenolytics
- drying agents
- disinfectants
Cerumenolytics
- Mainly for waxy/lipid containing contents. Contain ingredients that emulgeate wax and lipids, such as Dioctil Sodium (DSS), Calcium Sulphosuccinate, squalene and glycerin
• SQUALENE - Not ototoxic, no worries if rupture of tymp - also not more expensive, less effective etc, so use it!!!
Drying agents
When very maceratied wet ears, drying out ear properly important!
Lower the pH of the ear, cause ceratolysis, and slight antimicrobial effect.
• Boric acid, salicylic acid, benzoic acid, acetic acid, lactic acid
Disinfectants
Damage of microbes - purulent ears important
They potentiate the effect of antimicrobials by destroying bacterial cell wall, lowering resistance, and dissolving biofilm.
• Chlorhexidine, tris EDTA
• Chlorhexidine is available in multiple concentrations. The higher the cc the more effective, and more irritative chlorhexidine is (Middle Ear!) use LOWER conc!!!!
What are the steps of approching otitis externa?
Step by step
- : History
- : Examining the ear
- : Otoscopic examination
- : Cleaning
- : Repeated otoscopic examination, evaluating cleaning, further cleaning if necessary
- : Sampling
- : Sending the patient home with preliminary treatment
- : Modifying treatment based on progress (Control)
Treatment of otitis externa - overview of possibilities
• Cleaning is enough on its own • Specific treatment - Antibiotics - Antimicotics - Antiparasitics • Anti-inflammatory drugs • Diet (allergy - atopic dermatitis)
Sampling
- cytology is best sample, shows everything we need to know!!
- microbio may be misleading - normal flora of ear
- problem - treat, no problem - dont treat!
Topical or systemic treatment?
- Topical: Very beneficial in case of non ototoxic materials, as topical concentration is a lot higher(!!!), and can break through antibiotic resistance. Available drugs choice is limited in case of a perforated TM.
- Systemic: Beneficial in middle ear involvement, but reaches the ear in very low concentration + side effects (Not always possible - dog wont let you do it - systemic sometimes only option)
- Decision should be on a case by case basis
What happens with an untreated OE?
OE IS A PROGESSIVE DISEASE!
• Untreated acute otitis externa (OE) can progress into chronic OE
- Sebaceous gland hyperplasia
- Epithel hyperplasia
- Hyperkeratosis
- Ceruminous gland hyperplasia
- Follicular hyperplasia
- Ceruminous glands dilate > Cerumen production increases > Increased humidity and pH, lowered lipid concentration of cerumen
- Long term effect: Apocrine gland rupture, sebaceous gland degeneration, auditory canal fibrosis, stricture, calcification
–> may turn irreversible - resection surgery!
Name the 5 most common causes of OE
90% of cases its one of these! • Bacterial otitis externa • Malesseziosis • Parasitic otitis externa • Foreign bodies • Masses
Bacterial OE
Secondary, requiring primary: - Allergy - Foreign body or predisposing factors: - Too much hair - Water in the ear
Bacterial OE agents
🔺Part of flora - can mult fast if predisposing, already there!
• Staphylococci: Part of the flora of the healthy ear canal
• Streptococci: Also part of healthy ear flora, except for ß hemolyzing
🔺Not in flora:
• Pseudomonas (Not part of ear flora in this climate - tropical!)
Hard to rid of, multires, but on its own we can treat eventually. From ground dog can scratch into ear.
Cononizers, rare:
• Escherichia Coli
• Enterobacteriaceae
• Proteus
Bacterial anamnesis/ how can you recognize bacterial OE?
- Patient shows signs of OE (pain, scratching)
- Ear starts to stink, unique smell
- Purulent discharge in neglected cases
- Common in dogs, extremely rare in cats (if pus in cat, probably polyp!)
How can we recognize the staphylococcus OE
Inflamed, white discharge
- CONCAVE SURFACE OF THE EAR(ext): Erythematous, in certain cases, dried pus at the entrance of the ear canal (Hyperkeratotic apperance)
- WIDTH AND LENGTH OF EAR: Mild narrowing
- QUALITY AND AMOUNT OF DISCHARGE: Medium – large amount of white, creamy purulent content
- SKIN OF THE EAR: Erythematous inflammation, reddened, bleeding, smooth
- SENSITIVITY: Increased, painful
- TM: Intact
How can we recognize the pseudomonas aerginosa OE
Purulent ulcurative!!
- CONCAVE SURFACE OF THE EAR: Slightly reddened, dry, elastic brownish contents, wet leaf smell
- WIDTH AND LENGTH OF THE EAR: Usually mild narrowing, depending on skin edema
- AMOUNT AND QUALITY OF DISCHARGE: (small-)large usually! amount - can fill the whole ear!, creamy purulent, brownish contents
- SKIN OF THE EAR: Inflamed, bleeding ulcers, glands appear as micro-abscesses (gland sealed by inflamm, bacteria access, growth, rupture, ulcer)
- SENSITIVITY: Increased, painful
- TM: Intact, but pseudomonas can migrate through - dull not shiny indicate otitis media!
Cytology
• Large amount of coccoid/rod shaped bacteria, even bacteria clouds. (As some bacteria/fungi in flora, if we see 5-10 cocci its okey)
- cocci: staph, strept (G+)
- rods: psudomonas (G-)
• WBC+Phagocyted bacteria indicates there is a problem.
(Swab smear, diff quick stain)
When should we OE microbiology?
As bacteria etc are part of the flora, it is important to only use the results for:
• In case of plannig per os treatment
• In case of middle ear involvement
—- and NOT to check if the microbes are the cause of the OE! Microscopy is used for that.
What are the main points of the OE treatment?
- cleaning
- specific treatment of cause
- anti-inflammatory drugs
- diet (allergy! Ask about it)
Define the use of different cleaning strategies in practice
After cleaning prescribe these IF they are indicated:
• Disinfectants: Recommended
• Cerumenolytics: Occasionally (mixed infection)
• Drying agents: In case of severe! maceration
Describe the practical use of specific treatment of the cause
• Antibiotics: Based on resistance (OM) or in case of topical use, can be used ‚blindly’. Not always required to achieve a healthy ear - cleaning may be enough!
• Chloramfenicol, Florfenicol: Staphilococcus, Streptococcus
- Good for cocci!
Not intended for hu use so good in case of resistance
Most products cont these made for long term - owner doesnt have to admin a lot bc works onger time
• Marbofloxacin, Ciprofloxacin: Pseudomonas (Also used in hu - always confirm pseudomonas infection in case of use)
Describe the practical use of anti-inflammatories
Glucocorticoids in
case of severe dermatitis and ulcers.
Malesseziosis occurance
- Responsible for 99% of mycotic otitis (Candida, aspergillus rarely)
- Part of physiological flora
- Bowling pin shaped/shoe print, unicellular, microscopic fungi
- Increased humidity promotes their growth
- Casues very itchy, proliferative otitis
Malessezia pachydermatis – Anamnesis
- Sudden onset of uni/bilateral scratching that comes together with pain
- Swimming is part of anamnesis
- Symptoms of food allregy (scratching on full body)
- Ear reminds of Yeast but worse..
- Common in dogs, extremely rare in cats
Malessezia pachydermatis – Physical examination
Wrinkling, pattern - dark muddy disch
1. CONCAVE SURFACE OF THE EAR: Thickened, forming wrinkles, slightly reddend, dark brown, porous discharge
2. WIDTH AND LENGTH OF THE EAR: Mild-severe stricture
3. AMOUNT AND QUALITY OF DISCHARGE: small-large amount, brown, smelly, mudlike discharge
4. SKIN OF THE EAR:
Inflamed, cobblestone pattern!!, proliferation
5. SENSITIVITY: Increased, painful
6. TM: Intact, difficult to evaluate beacuse of discharge
Cytology of malessezia
Bowling pin shaped fungi in large amounts!
Treatment of melassazia
🔺Removing this large amount of mud like wax very helpful!
•Cerumenolytics: Thick, ceruminous, lipid rich content makes these the optimal choice
•Disinfectants: Only in case of mixed infections
•Drying agents: Reducing humidity helps treatment
🔺Antimycotics: Based in microbiology. Not necessary for a successful treatment in most cases.
🔺Anti-inflammatory drugs: depending on level of dermatitis, glucocorticoids can be recommended for the inflamed glands - pattern wrinkling
Parasitic Otitis Externa occurance
- Ear mites – otodectes cynotis are the most common
- Demodicosis (but if they pose a problem, the ear is not the first site)
- rarely ticks can be present
Otodectes Cynotis
Ear mites!
• More common in cats, but can cause problems in dogs as well
• Can be present at any age, but mainly young animals are affected
• Contact infection, can live outside of the ear canal
• Zoonosis! Gloves!!!
Otodectes Cynotis – Anamnesis
•Intensive scratching, shaking •Black, crust contents in the
environment from ears (in case of cats) •„Adopted Kitten” syndrome
Otodectes Cynotis – findings on Physical exam
We see them moving around with the otoscope!
1) CONCAVE SURFACE OF THE EAR – Sometimes looks like intact, but black, crustous contents in case of cats
2) WIDTH AND LENGTH OF THE EAR – usually normal, though the black crust may obstruc!
3) SKIN OF THE EAR – reddened, inflamed
4) AMOUNT AND QUALITY OF DISCHARGE – Black-brown, coffeelike, filling the ear canal
5) SENSITIVITY OF THE EAR – very painful
6) TM - intact
Otodectes Cynotis – Citology
.. contrast slide of the brown crusty bits..
Treatment of ear mites?
• Cleaning (Rids of most of mites and contents! Incr effectivity of tratment!)
- Cerumenolytics are more effective than disinfectants
• Specific treatment
- More possibilities, topical Tiabendazol is the best!! Ear drops
- Systemic treatment: spot-on, tablets. 80-85% efficacy… good for prevention not treatment.
–> Selamectin, Imidacloprid/moxidectin, Ivermectin(!)
Occurance of foreign body as cause of OE
• Most common (99%): grass awn
• Seasonal, usually in outdoor pets
• Can be predisposing factor for bacteria and fungi
(Fox tail, childrens toy pieces)
Anamnesis of foreign body as cause of OE
• Very painful, sudden onset, unilateral
• Shaking, head tilt, ear scratching
• Owner can sometimes see the foxtail going into the ear
(May be hard to see the FB - sedation may be a good idea!)
Foreign bodies – Physical examination
- CONCAVE SURFACE OF THE EAR: Intact
- WIDTH AND LENGTH OF THE EAR: Normal
- AMOUNT AND QUALITY OF DISCHARGE: Blood, debris, pus
- SKIN OF THE EAR:
Intact/damaged/inflam ed - SENSITIVITY: Increased, painful
- TM: Depending on the location of the foreign body
How can we differentiate the FB from hair?
May be hair! How to diff from FB?
Foxtain/awn - straight, small ridges eg like spider legs, backwards hairs
Should we do any cytology/microbiology in FB?
Yes! We dont know what microbes entered with the FB! Or irritation of flora - out of balance
Treatment of FB in ear
- Removal of foreign body = Best solution (Important not to push the FB thrpugh the TM -> iatrogenic perforation!!!)
- Cleaning – very carefully (Gentre water pressure, dont push anything into ear)
- Protocol should be followed after foreign body removal. - schedule a check up!
Masses general occurance
- Huge differences between cats and dogs
- Dogs: Papilloma are most common, then adenocarcinomas. Polyps are rare.
- Cats: Polyps are the most common
Masses - dogs occurance
- Older age
- Rare
- Unilateral
- Viral papilloma are often seen, but can be frequently mixed with proliferative inflammations
- If it is not a papilloma it is usually a malignant tumor
Masses – Dogs – Anamnesis
- Chronic, the problem is not responding to treatment
- Smelly, bloody discharge
- Severe middle ear symptoms
Masses – Dogs – Physical examination
- CONCAVE SURFACE OF THE EAR: Intact, or visible mass
- WIDTH AND LENGTH OF THE EAR: Narrowed
- AMOUNT AND QUALITY OF DISCHARGE: Blood, debris, pus
- SKIN OF THE EAR:
Inflamed, irregular - SENSITIVITY: Increased, painful
- TM: usually not visible
Can we use additional examinations for masses?
Not really..
• Cytology/Microbiology:
- Usually not specific, however sometimes signs of secondary
infection is visible, which can distort the doverall impression
• Histopathology
- Rarely representative due to difficulties of sampling.
Masses - how to treat
• CT (Cant know extent of mass! Operable or not? Well localized eg good to remove)
• Total ear canal ablation (Ventral
bulla osteotomy (TECA+VBO) based on CT)
• Hard laser
Polyps
• Usually young-middle aged cats (Main coon, Norwegian forest cat!)
• French bulldogs and pugs
• Uni-bilateral
• Respiratory symptoms
• Can be asymptomatic
(Small angiofibroblast growths orig in middle ear
Growth - into .. tube into nasopharynx and or into ext ear.
Polyps – Anamnesis
- Usually after 6 months, head tilt, ear scratching
- Sometimes stridor
- Large amount of smelly discharge
- Horner’s syndrome
Polyps – Physical examination
Polyp embedded in white smelly discharge
1. CONCAVE SURFACE OF THE EAR: Intact, large amount of discharge or visible polyp
2. WIDTH AND LENGTH OF THE EAR: obstructed
3. AMOUNT AND QUALITY OF DISCHARGE: White, smelly discharge
4. SKIN OF THE EAR:
Inflamed, irregular
5. SENSITIVITY: Increased, painful, itchy
6. TM: usually not visible;
Early cases can se exiting the TM! Usually the TM is just gone…
Polyp - Additional examinations
- Cytology: Usually not specific, rods can be present
- Microbiology: E. coli
- Histopathology: Since a large piece can be removed, it is always a good idea to take a sample
Treatment of polyps
- Traction removal (Grasp and pull out (GA). Twist like they did in the practice month?)
- Glucocorticoids (prednisolone) 1mg/kg/d for two weeks
- If remission/inadequate response: VBO
