sash : pyoderma malodourous malassezia and fecund fleas by dr linda vogelnest

Pesky Pyoderma, Malodourous Malassezia, & Fecund FleasLinda Vogelnest BVSc MACVSc FACVScSpecialist Veterinary DermatologistAssociate Lecture University of Sydney

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Bacterial Pyoderma• Superficial &/or Deep

• 2° to

– Allergies – AD (can markedly pruritus)

– Systemic immune suppression

• Immuno-suppressive therapies (e.g. pred)

• Disease (e.g. neoplasia, FIV)

– Hormonal – hypoT, hyperA (can cause pruritus)

– Keratinisation defects - primary seborrhoea, sebaceous adenitis

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Bacterial Pyoderma• Superficial &/or Deep - 2° disease

• Problems

– Diagnosis – variable presentations

– Treatment

• Clear current infection - duration key

– New antibiotic resistance – drugs + duration

• Manage 1° disease – AD common, difficult

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Bacterial Pyoderma• Historical clues

– Species/breed/age

• Dogs – any skin disease, age, breed

• Cats – young (allergies); aged

– Pruritus – absent to severe

– Poor/loss of steroid-responsiveness

– Recent illness, immuno-suppressive drugs

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Bacterial Pyoderma

• Clinical clues

– Lesions - superficial

• Pustules, papules;

epidermal collarettes

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Bacterial Pyoderma

• Clinical clues


• Pustules, papules; epidermal collarettes

• Alopecia – well-demarcated to patchy diffuse

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Bacterial Pyoderma

• Clinical clues



• Alopecia – well-demarcated (to patchy diffuse)

• Non-specific – erythema, erosions, scaling, crusting,

lichenification, hyperpigmentation

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Bacterial Pyoderma• Clinical clues




• Non-specific – erythema, scaling, crusting, lich/hyperpigmentation

• Regional forms:

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Bacterial Pyoderma

• Clinical clues

– Lesions

• Pustules, papules; epidermal

collarettes

• Alopecia – well-demarcated (to

patchy diffuse)

• Non-specific – erythema, scaling,

crusting, lich/hyper

• Regional forms

• Other forms

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Bacterial Pyoderma

• Clinical clues




• Non-specific – erythema, scaling, crusting, lich/hyper

• Regional forms

• Other forms

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Bacterial Pyoderma

• Clinical clues

– Lesions – superficial

– Lesions – deep

• Nodules, draining tracts

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Bacterial Pyoderma

• Clinical clues



• Pseudomonas deep pyoderma

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Bacterial Pyoderma

• Clinical clues



• Solar deep pyoderma

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Malassezia dermatitis

• 2° to

– Allergies – AD (can markedly pruritus)

– Systemic immune suppression

• Immuno-suppressive therapies (e.g. pred)

• Disease (e.g. neoplasia, FIV)

– Hormonal – hypoT, hyperA (can cause pruritus)

– Keratinisation defects - primary seborrhoea, sebaceous adenitis

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Malassezia Dermatitis

• Historical clues

– Breeds - WHWT, Basset, Cocker, Shih Tzu, Dachshund;

Devon Rex

– Pruritus - often severe

– +/- Odour

– Poor/loss of steroid-responsiveness

– Concurrent illness, immuno-suppressive drugs

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Malassezia Dermatitis

• Clinical clues– Lesions

• Erythema, scaling; brown nails

• Lichenification, hyperpigmentation, odour

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Diagnosis• Skin cytology

– Adhesive tape impression (all lesions)

• Diff-Quik stain (no fixative)

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Diagnosis

• Skin cytology– Adhesive tape impression (all

lesions)– Glass slide impression (moist

lesions)

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Tape Impression - Normal skin - 4X lens (40x magnification)Keratinocytes dominate; normal flora very sparse

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Tape Impression – Pyoderma 4X lens (40x magnification)Clumped keratinocytes; Neutrophil rims/clusters

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4X lens (40x magnification)

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Degenerate neutrophils with intracellular cocci – oif (1000x)

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Neutrophils with intracellular & colonising cocci – oif (1000x)

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Keratinocytes with melanin granules – oif (1000x)

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Tape Impression – MD 4X lens (40x magnification)

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MD – oil lens (1000X)Dx = >1 yeast per oif

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Pyoderma & MD - Diagnosis• Surface cytology

– Most important

– Not 100% sensitive (esp. pyoderma)

• Clinical appearance

– May be suggestive (papular lesions; follicular moth-eaten alopecia; nodules/discharge)

• Consider treatment trial

– Antibiotics or antifungals alone (3wks min - superficial)

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Pyoderma & MD - Treatment1. Treat the infection first (underlying dz 2nd)

Systemic most reliable (min. 3wk course)

MD

Itraconazole 5-10mg/kg SID

Terbinafine 30mg/kg SID

Pulse tx: 2 consecutive days/wk

Pyoderma

Cephalexin, amoxyclav

Doxycycline, TMS, clindamycin

Rifampicin, chloramphenicol, enrofloxacin

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Pyoderma & MD - Treatment

1. Treat the infection first (underlying dz 2nd) Systemic most reliable (min. 3wk course) Topicals can be useful MD - Enilconazole rinse, miconazole/terbinafine

cream Pyoderma - Mupirocin, fusidic acid, silver

sulphadiazine Both - Chlorhexidine solution (2-3%) sid-bid

Shampoos – adjunctive only (limited residual effect)Chlorhexidine, miconazolePiroctone olamine, econazole

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1. Treat the infection first (underlying dz 2nd)

• Systemics &/or topicals

• NO concurrent steroids

– Incomplete/delayed resolution of infections

– Encourages antimicrobial resistance

– Pruritus markedly reduced in 24-48 hours without steroids

DON’T use pred & 5-10 days antibiotics !!

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Pyoderma & MD - TreatmentDiagnosis uncertain?

– Options1. Antibiotic or antifungal treatment trial

(3wks; no steroids) – Pruritic: pruritus & lesions should

improve by 5-7d– Non-pruritic: lesions should resolve by

2-3wks2. Steroid-treatment trial (2-7 days; no

antibiotics/antifungals)– Pruritic: pruritus and lesions should

improve notably by 7d– Non-pruritic: not indicated!

3. Referral?DON’T use pred & 5-10 days antibiotics !!

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1. Treat the infection first – systemics &/or topicals (no steroids)

2. Address the underlying dz next – if possible!

3. Options for recurrent pyoderma/MD (e.g. immune suppression; AD)1. Pulse antimicrobials – encourage development of resistance2. Intensive topical therapies

» Chlorhexidine/piroctone olamine/azole shampoo 1-2 times wkly» Bleach baths (0.005%) = 50ppm [6% bleach: 1ml per 1.2L]» Chlorhex 2.5% spray, Resichlor® or Pyohex Leave on Lotion® -

SID?3. Maximise Skin health

» Skin Barrier Repair – moisturising; fatty acids» Balance Diets – fatty acids» Shampoos – appropriate, non-drying

4. More aggressive disease control – cyclosporine for AD

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Methicillin-Resistant Pyoderma

= Resistance to• β-Lactam Ab’s - Cephalexin, amoxyclav• Often several other drug classes: MDR

–World Trends for S. pseudintermedius• ~98% sensitive to cephalexin, amoxyclav for >20yrs• First methicillin resistance (MRSP) – 1999 (Dogs: Illinois, USA)• Increasing MRSP 2006 (healthy dogs + skin dz)#

– ~7% many countries – Canada, Europe, parts USA– 10% Spain, 17% Korea– 27-38% parts USA, 30-66% Japan

# van Duijkeren E, Catry B, Greko C et al. Review on methicillin-resistant Staphylococcus pseudintermedius. J Antimicrob Chemoth 2011;66:2705-2714.

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= Resistance to• β-Lactam Ab’s - Cephalexin, amoxyclav• Often several other drug classes: MDR

–World Trends for S. pseudintermedius• Worldwide – 7-60% MRSP (more dogs than cats)• Sydney, Australia

– 27 cases (Aug 2010-Sep 2012; no Ab’s previous 2wks)#» 24 S. pseudintermeudius; 3 S. schleiferi » 1 (4%) – MRSP + MDR; 26 (96%) sensitive cephalexin, amoxyclav

– 55 cases (Nov 2012-Jul 2013; no Ab withdrawal)» 6 (20%) of 29 dogs – MRSP + MDR

# Ravens et al. Canine superficial bacterial pyoderma: screening for antimicrobial resistance in causal Staphylococcus isolates, and comparison of culture sampling methods; AVJ in press.

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= Resistance to

• Β-Lactam Ab’s - Cephalexin, amoxyclav

• Often several other drug classes: MDR

–World Trends for S. pseudintermedius

• Worldwide ~ 7-60% MRSP (more dogs than cats)

• Sydney, Australia ~20% (dogs)

• Small no. MRSP clones disseminated worldwide

– Prior Ab use; hospitalisation; urban areas = risk factors

» DON’T use pred & 5-10 days antibiotics !!

– Vet Hospital hygiene important to limit spread

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1. Culture Samples

1. Pustules – 25g needle, dry swab sample

2. Other lesions – dry swab rubbed vigorously 5 sec

– Dry swab, saline-moistened swab, skin scraping similar#

» Minor variation in isolates with method (6/29 dogs)

» Interpret with care; in relation to skin cytology

» Repeat samples?

• # Ravens et al. Canine superficial bacterial pyoderma: screening for antimicrobial resistance in causal Staphylococcus isolates, and comparison of culture sampling methods; AVJ in press.

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1. Culture Samples

1. Pustules – 25g needle, dry swab sample

2. Other lesions – dry swab rubbed vigorously 5 sec

2. Sensitivity testing SP isolates Sydney#(27 dogs; 227 isolates)

• Cephalexin, amoxyclav, TMS (96%)

• Enrofloxacin, chloramphenicol (96%)

– Less to doxycycline (78%), clindamycin (88%), cefovecin (90%)

• # Ravens et al. Canine superficial bacterial pyoderma: screening for antimicrobial resistance in causal Staphylococcus isolates, and comparison of culture sampling methods; AVJ in press.

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Pyoderma & MDQUESTIONS?

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Flea Allergy/Flea Control

• Flea problems common – cats, dogs– Diagnosis of Allergy – sometimes missed– Treatment – sometimes challenging

• Historical clues for Flea Allergy– Signalment

• No breed predilections• Age of onset - typically 3-5yrs

– Pattern of pruritus• Severe; intermittent, suddenly flaring• Typically seasonal - late summer/autumn worst

– Flea control history• Regular monthly flea prevention• No evidence fleas/flea dirt (more likely with regular control)

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Clinical Lesions - Dogs

• Lesions

– Acute

• Papules

• Self-trauma – alopecia, excoriations

• “Hot spots”

– Chronic

• Lichenification

• Hyperpigmentation

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Clinical Lesions - Dogs

Distribution

– Caudal ½ of body

• Dorsal lumbosacral area

• Flanks

• Caudomedial hindlimbs

• Ventral abdomen

• Umbilical area

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Clinical Lesions - Cats

• Lesions - variable– Self trauma - mild to severe

• Alopecia, excoriations, crusting, ulcers– Non-inflammatory alopecia– Miliary dermatitis– EGC lesions

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Clinical Lesions - Cats

Distribution

– Caudal ½ of body

• Dorsal lumbosacral area

• Caudomedial hindlimbs

• Ventral abdomen

– Neck/shoulders

– Lips

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Flea Allergy Diagnosis

Response to flea treatment trial (4wks)

1. Affected pets - control

2. In-contact pets - regular control

3. Environment - IGR treatment

marked reduction in pruritus/clinical signs by 4wks

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– Product Choice - consider– Product efficacy– Coat length/density– Frequency of bathing, swimming– Ability of owner to apply effectively– Cost


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• Flea Life Cycle– Adults

• Feed <5min• Mate 8-24hrs; lay eggs by 24-36hrs (40-50/day)• Only 8-15% adults move to other hosts

– Eggs• Fall off pet into resting areas• Hatch 1-6d - RH>50%; 4-35°C

– Larvae• Motile – “down, into dark” (moist, cool sites)• Pupate in 8-14d – temp & food dependent (faeces, eggs)

– Pupae• Very resistant• Adult emergence in 2wks-6mnth- vibration, warmth

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Flea Allergy/Flea Control– Flea control for flea allergy

• Adults – feed 5min; eggs by 24-36hrs1. Quick reduction in flea numbers2. Reduced flea feeding times– Adulticides – kill rates/speed of kill/duration effect

• Nitenpyram - 100% kill by 3hrs (dogs), 4hrs (cats); 92% by 72hr

– Sig. less flea feeding within ≤ 15mins• Spinosad - 100% kill by 24hrs; 85-100% kill + 100% less eggs

by 30d– >90% kill by 2hrs (cats); 81-100% by 4hrs (dogs)– 95-96% dogs flea free by 3mnth cf. 64% selamectin

cf. 38% fipronil#– IVERMECTIN toxicity… beware!

#Dryden Vet Parasitol 2012

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Flea Allergy/Flea Control• Flea control for flea allergy

1. Quick reduction in flea numbers2. Reduced flea feeding times– Adults – feed 5min; eggs by 24-36hrs– Adulticides – kill rates/speed/duration effect


• Spinosad - 100% kill by 4-24hrs; 85-100% + 100% less eggs by 30d

• Imidacloprid - 95-100% kill by 8-12hrs; 95% by 30d– 83% kill by 8hrs (cats)– Reduced flea feeding by 3-5mins (cf 60min

fip/sel) – d7, d14– Lower flea kill rates Advantix® vs Advantage®#

McCall, Int J Applied Research in Vet Med 2004

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• Imidacloprid - 95-100% kill by 8-12hrs; 95% by 30d• Fipronil - 98-100% kill by 12-18hrs; 93-95% by 30d

– 63% kill (cats), 47% kill (dogs) by 8hrs– 38% flea free by 3 mnths (cf. 64% selamectin;

95% spinosad)#• Selamectin - >98% kill by 36-42hrs; 95% by 28d

– 74% kill by 8hrs#Dryden Vet Parasitol 2012

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• Imidacloprid - 95-100% kill by 8-12hrs; 95% by 30d• Fipronil - 98-100% kill by 12-18hrs; 93-95% by 30d• Selamectin - >98% by 36-42hrs; 95% by 28d• Permethrin (dogs only) - data? – repellant action• Indoxacarb (Activyl®) - 98% kill by 7d; 95+% by 30-45d

– Cf. fipronil/methoprene 85% kill by 7d; 50% by 30d#– 100% less eggs (cats) by 72hrs*

Dryden; Parasites and Vectors #Dec 2013; *Mar 2013

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• Flea Allergy Control1. Quick reduction in flea numbers2. Reduced flea feeding times– Adults – feed 5min; egg by 24-36hrs– Adulticides – kill rates/speed/duration effect

• Multiple options 95-100% kill without environ. tx by 60-90d (Florida)#

– Fipronil, Imidacloprid, Lufenuron (+pyrethrin or nitenpyram), Selamectin

• New Options?– Imidacloprid/flumethrin collar (Seresto®) – 95% kill

x 7-8mnth (d&c)» 99.5-100% kill by 24hrs cf 73% for

fipronil/methoprene cf 66-83% for …..– Deltamethrin collar (Scalibor®) – up to 6mnth flea– Dinotefuran/Permethrin/Pyriproxyfen (Vectra®)

» 87% kill by 7d; 99% kill by 48hrs#Dryden et al Vet Parasitol 2011; 182, 281-286

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marked reduction in pruritus/clinical signs by 4wks

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Product Choice - consider Product efficacy Coat length/density Frequency of bathing, swimming Ability of owner to apply effectively Cost

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1. Affected pets• Spot-on or spray - every 2wks

• Imidacloprid (Advantage®) • Fipronil (Frontline®) spray

• Oral• Nitenpyram (Capstar®) - daily• Spinosad (Comfortis®/Panoramis®) -

fortnightly• Topical rinses

• Permethrin (Permoxin®) 1-2 times wkly with Capstar® (DOGS ONLY!)

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1. Affected pets2. In-contact pets

Similar products – monthly Aim to prevent large burdens

3. Environment - all pet resting/laying/sleeping/travelling areas

• Vacuuming– Remove ~90% eggs/50% larvae– Stimulates pupal emergence

• IGR treatment - Raid, Mortein, Baygon “egg killer”sprays– Methoprene (UV-degraded)– Pyriproxyfen, Fenoxycarb (UV-stable)

Flea Control

Questions?

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Level 1, 1 Richardson Place, North Ryde 2113, Sydney, NSW

sash : pyoderma malodourous malassezia and fecund fleas by dr linda vogelnest

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