Campbell Derm Fall 2009

Front 1

what do keratinophilic fungal organisms "feed on"?

Back 1

stratum corneum, nails, and anagen hair

Front 2

what facilitates dermatophye invasion?

Back 2

disruption of skin barrier or trauma

Front 3

where do hyphae proliferate?

what do they do there?

Back 3

on hair surface-->keratolytic enzymes-->penetration of the hair cutivle-->migrate down hairshaft until reacy keratogenous zone (Adamson's fringe)

Front 4

explain dermatophytosis pathogenesis

Back 4

dermatophytes produce toxins-->inflammation (clinical signs)-->CMI activated

Front 5

what would contribute to a persistent/recurrent dermatophyte (i.e. ringworm (infection)?

Back 5

substances produced-->CMI supression

Front 6

name 3 conditions that may contribute to dermatophyte infections

Back 6

-hot, humid environment
-transmission via contact w/ infected hair, scales, or fungal elements
-hair shafts in environment infectious for months

Front 7

classic dermatophyte lesion

Back 7

annular area of peripherally, expanding alopecia, scale, crust, papules, and pustules

-face, limbs, paws, and tail

Front 8

dermatophyte lesion types: dogs

Back 8

-nasal folliculitis and furunculosis
-generalized seborrhea-like infection
-dermatophytic kerion
-onchyomycosis (nail infection)

Front 9

is really a _______, but is actually at dermatophytosis

Back 9

hot spots, acne

Front 10

feline dermatophytosis lesions

Back 10

generalized more common

-alopecia, erythema, scales, crust, papules, deneralized seborrhea-like eruption

local types: alopecia, may mimic chin acne or "stud tail", onychomycosis, dermatophte kerion, dermatophyte pseudomycetoma

Front 11

what commonly causes milliary dermatitis in cats?

Back 11

fleas

Front 12

what are the 4 strains of microsporum that fluoresce under a wood's lamp?

Back 12

canis, audouinni, distortum, schoenieinii

505 of canis fluoresce so good screening test

Front 13

dermatophytosis Dx

Back 13

-woods light
-microscopic exam. (KOH or chlorphenolac to clear keratin)
-fungal culture (most reliable)
-DTM (don't rely on color changes, must use microscopy)
-RSM

Front 14

Dermatophytosis treatment

Back 14

-spontaneous (usually only if localized)
-correct underlying problem
-reduce contagion
-hasten infection resolution

Front 15

DTM:

Dermatophytes utilize ________ in the media leading to __________ metabolites changing the color to _________.

Back 15

protein; alkaline; red

Front 16

Lime sulfur

Back 16

antifungal, antipuritic, drying

odor, stains

Can also use Miconazole/Chlorhex but more expensive and less effective

Front 17

How long do you continue Tx for dermatophytosis

Back 17

Until 3 neg cultures

Front 18

Who gets systemic Tx for dermatophytosis?

Back 18

multifocal, long haired, CATS, not responding to topicals in 2-4 wks

Front 19

*Griseofulvin

Back 19

can lead to bone marrow suppression

Front 20

*Ketoconazole and Itraconazole

Back 20

Hepatotoxic. Give with food (needs acidic environment)

Front 21

*Terbinafine

Back 21

Cheap

Front 22

*Lufeneron

Back 22

minimal efficacy

Front 23

Vaccines

Back 23

little efficacy for dermatophytes

Front 24

*Fluconazole

Back 24

doesn't seem to be absorbed well

Front 25

How do you clean the environment of dermatophytes?

Back 25

0.5% bleach and hot water. get rid of bedding etc.

-clean, transitioning, and infected cat rooms in catteries

Front 26

When to do Sx with dermatophytosis?

Back 26

to remove mycetomas and pseudomyecetomas

Front 27

Sporotrichosis

Back 27

Mucocutaneous fungi

"rose bush dermatitis"
-assoc w/ innoculation via plant thorns or seeds

-elongated intracellular yeast organisms present in histo

-Wear gloves --> zoonotic

Front 28

Sporotrichosis Tx?

Back 28

Itraconazole

Front 29

Pythium and Lagendium

Back 29

-aquatic

-may go systemic (pythium-->GI; lagendium-->large vessel invasion)

-German Shepherds predisposed

-"swamp cancer"

-invasive, often fatal

-remember pic of shep's leg completely raw and disgusting

Front 30

Pythiun Dx and Tx

Back 30

Dx: biopsy (histo and culture) and serology

Tx: aggressive amputation, itraconazole+terbenafine

Tx 2 months and recheck titers

Front 31

Deep mycoses

Back 31

Blasto, histo, coccidio, crypto

Front 32

Blasto

Back 32

-N rich soil (bat and bird droppings) (MS and OH river valleys)

-nodular lesions, concurrent resp issues

Dx: cyt, bio, sero, radiographs

Tx: Itra, AmphoB, Keto (if can't afford itra)

-pic of cat with huge distal forelimb

Front 33

Histo

Back 33

-Eastern USA

-GI and resp more common than skin Dz

-Dx: same as for blasto but no rads
Tx: itra, amphoB

Front 34

Coccidio

Back 34

-sandy, alkaline soil, high env temp, low rain, low elevation, SW US, S and Central America

Canine: young males; cough, dyspnea, fever, anorex, lameness, eye Dz, papules, nodules, abscesses, draining tracts, ulcers, SKIN LESIONS OVER INFECTED BONE

Feline: rare, but same types of signs

Dx: Hx (esp. where traveled), cyt (spherical, but rarely found), bio

Tx: same as others

Front 35

Crypto

Back 35

-pigeon droppings

-common in CATS

-nodules, ulcers, draining tracts, nasal discharge, sneezing, blindness (if in eyes), neural involvenment

Dx: cyto, bio, sero

Tx: itra, fluconazole, flucytosine

Tx for 2 mos after clinically normal

Can to capsular Ag titer to monitor how well therapy working

Front 36

Malassezia Dermatits

how many species?
commensal or opportunistic?

Back 36

7 species: pachydermatits, furfur, globosa, obusa, restricta, sloofia, sympodialis

-opportunistic

-cats and dogs. majority of dogs who get it have allergies, keratinization disorders, or other skin Dz, dec immunity, genetic predisposition, etc.

Rex cats predisposed

Front 37

What do Malassezia spp. like to grow on?

Back 37

lipids

Front 38

DOG Malassezia dermatitis lesions

Back 38

VERY itchy, generalized (greasy, smelly, scaly, crusty, lichenification, alopecia, hyperpig.)

Lips, muzzle, interdig. spaces, ventral neck, medial thighs, groin, axilla, intertriginous areas, paronychia

*40% have concurrent pyoderma*

look like rhinos, and nails have dark color on them that can be scraped off

Front 39

CATS Malassezia dermatitis

Back 39

not as common as in dogs

localized: otitis, chin acne, paronychia (discolored nails-->can scrape off)

generalized: erythema, scaly, way dermatitis

Front 40

Malassezia dermatitis Dx and Tx

Back 40

cyto (impression, swab, skin scraping, acetate prep, tape) --> round to oval budding yeast "peanut shape"

bio with histo --> cyto BETTER for this

culture (add oil)

xenoDx

Tx: *ID and ADDRESS underlying causes! and Tx concurrent staph pyoderma

topicals, systemics itra or keto (Griseofulvin doesn't work)

Front 41

Name the important flea species

Back 41

Ctenocephalides felis
Ctenocephalides canis
Echidnophaga gallinacea
Pulex sp. (i.e. irritans)

Front 42

What's another name for Echidnophaga gallinacea?

who has it and who gets it?

Back 42

"face flea" or "stick tight flea"

POULTRY flea that DOGS can get
(lay eggs in burrow on host-->larvae drop to ground)

Front 43

FLEA LIFE CYCLE

Back 43

Eggs: NOT sticky, laid on host-->fall-->hatch 1-10 days (or die)

Larvae: nonparasitic (dried blood), don't geotactic, photophobic, 3 molts in larval stage, 5-11 days

Pupae: sticky cocoon, resist desiccation, PEAK emergence 8-9 days (depends on temp and physical pressure)

Adult: attracted to host by mvmt, warmth, CO2, entire life on host, females lay eggs after blood meal (13-35 eggs/day)

Front 44

Flea facts

Back 44

poor survival at high altitudes

idea environment: 65-80 F and 75-80% RH

Front 45

Flea bite hypersensitivity pathogenesis

Back 45

Predisposure: atopics, intermittent exp. to FAD (cont. exp-->tolerance)

H- and LMW antigens in flea saliva cause the immune response

Front 46

Types of flea bite hypersensitivity

Back 46

I, IV, cutaneous basophil, and late phase IgE

Front 47

Type I

Back 47

immediate

Front 48

Type IV

Back 48

delayed/cell mediated

72h after bite

Front 49

Cutaneous basophil

Back 49

basophils have histamine, heparin, etc. in granules

18h after bite

Front 50

Late phase IgE

Back 50

6-8 h after bite

Front 51

Where will you find sensitivity reactions on body?

Back 51

DOGS: caudal 1/3 --> pruitis, papules, crusts, pyotraumatic dermatitis, and if chronic (alopecia, lichenification, hyperpig.)

CATS: caudal 1/3 of body and also on neck --> miliary dermatits, symm alopecia w/ NO lesions, eosinophilic granular complex

Front 52

DDX for flea allergies

Back 52

other hypersensitivities, bact. folliculitis, Cheyletiellosis, Sarcoptic mange, Malassexia dematitis, dermatophytes (esp. cats), and less commonly mycosis fungoides, and Rx rxns

Front 53

Dx and Tx

Back 53

Hx, PE, IDST, histo, xeno

test times depend on type of hypersensitivity caused

Tx: FLEA CONTROL, anti-itch, antibiotics

Front 54

Is immunotherapy effective for flea hypersensitivities?

Back 54

NO b/c basically mimics intermittent exposure-->no tolerance

Front 55

What other problems do fleas cause?

Back 55

-plague vectors
-int. host for D. caninum
-anemia
-irritating to host

Front 56

External and Internal env control

Back 56

Outside: restrict pets from trouble spots, keep grass short, remove organic debris, nematodes to kill larvae and pupae (if don't want to use insecticide), clean the car

Inside: Tx all animals, vacuum, mop, wash bedding, insecticides (adult IGRs recommended), borate cmpds (professionals, carpet)

Front 57

Organophosphates

Back 57

Cholinesterase inhibitors --> potent, good residual effect

Carbamates -->safer than OPs but don't work as well as more current products

TOXIC to cats

Front 58

Pyrethrins

Back 58

from Chrysanthemum flower

mem depol.

inact by UV

rapid kill, low resid effect, piperonyl butoxide often added

some cats allergic (add to allergy tests)

Front 59

Permethrins

Back 59

synthetic pyrethrins-->mem depol

more UV stable

FLEAS and TICKS!

Toxic to cats

Front 60

What cmpd in maj. of OTC spot ons?

Back 60

permethrins

Front 61

IGRs --> doesn't kill adults

Back 61

juvenile hormone analogs

kills LARVAE and EGGS

long resid effect (esp. pyriproxifen)

Front 62

what's in many OTC spot ons for CATS?

Back 62

IGRs

Front 63

Lufernuron (Program, Sentinel) --> doesn't kill adults

where is it stored?

Back 63

Chitin syth inhib (FLEAS and TICKS)

stored in body fat

slow acting

not effective for FAD patients

Front 64

Fipronyl (Frontline) --> needs q 1 mo to q2-3wk application

affinity for?

Back 64

phenylpyrazole

GABA receptor ANTAGonist (FLEAS and TICKS)

affinity for sebaceous secretions

can bathe animal

q 1mo for FAD patients

Front 65

Fiprinyl + S-Methoprene (Frontline Plus)

can you bathe the animal?

Back 65

GABA receptor antag + IGR --> prevents emergence of a fipronyl-resistant flea pop.

reg. bathing dec. efficiency

Front 66

Imidacloprid (Advantage)

Back 66

chloronicotinyl cmpd--> q 1 mo

post-syn nicotinic receptors

FLEAS

bathing dec efficacy

Front 67

Imidacloprid + Permethrin (Advantix)

Can you use it on cats?

Back 67

FLEAS, TICKS, and repels mosquitoes

TOXIC to CATS

Front 68

Selemectin (Revolution)

Not stored well in dogs but good for cats

How does it work?

Back 68

FLEAS, TICKS (D. variablis), HW, sarcoptes, otodectes, and some nematodes (hooks, rounds in cats)

Cl channel activator

Delay b/f death, but rapid action to prevent flea feeding and egg prod.

Front 69

ProMeris and Promeris Duo

for who?

Back 69

DOGS only!

metaflumizone: Na channel blocker (delay b/f death)

Waterproof

Duo--> amitraz for TICKS (5 sp. prevents attachment), and may do mites too

Front 70

Advantage Multi/Advocate

Back 70

imidacloprid and moxidectin

FLEAS, HW, T. cati and leoni, Unicinaria stenocephala, Otodectes cynotis

Imidacloprid washes off

Front 71

Spinosad (Comfortis)

Back 71

chewable 1 1mo

DOGS only

Nicatinoid insectacide (nicotinic Ach receptor AGONIST)

rapid flea kill (100% by 4h)

be careful if animal has seizure Hx-->may lower seizure threshold

Front 72

Vetra 3D

Back 72

dinotefuran, permethrin, pyriproxifen

DOGS only!

Neonicotinoid-->flea rapid kill

Permethrin--> repellant that kills fleas, ticks, and CATS!

Pyriproxifen is an insect GH analog

Front 73

Nitenpyram (Capstar)

Back 73

Flea adulticide only

PO, no resid activity, so can give often (elim. in 24 h)

Front 74

Citrus oils

Back 74

disrupt flea exoskeleton

in many OTC shampoos-->can be irritating and have other side effects, esp in cats

Front 75

Peduculosis --> lice (insects)

Back 75

host-specific

anoplura=sucking
malophaga=biting

winter

acetate tape

control w/ flea contol products

Front 76

Fly bite dermatitis (from stomoxys calcitrans)

Back 76

face and ear pinnae (erythema and hemorrhagic crusts)

use fly repellents, keep inside, topical Abx/seroid creams

Front 77

Mosquito bite hypersensitivity

who?--> CATS

Back 77

bridge of nose, ears, paws

crusting, errosive dermatitis --> resolves w/ removal of mosquito exposure

may mimic autoimmune Dz

Front 78

Myiasis

Back 78

eggs deposited onto wet, warm, skin of debilitated animals

lesions: punched out holes (can coalesce)

Tx: address underlying problem (tx shock, clip, clean, debride, Abx)

Front 79

Cuterebra

Back 79

eggs laid near nests or burrows

lesions: head, neck, trunk

SQ nodule w/ fistula

Tx: Sx removal (don't crush grub!), Tx like an abscess

Front 80

Hymenoptera (bees, wasps, hornets)

Back 80

local erythema, edema, inflammation

+/- urticaria and angioedema

Tx anaphylaxis

Front 81

Ants (Solenopsis invicta = "fire ant")

Back 81

venom cytotoxic and hemolytic

erythema, pain, pruitis w/in 15 min (subsides w/i 48 h)

Front 82

3 types of canine demodicosis

Back 82

follicular MITES!

Demodex. canis, injai (long body), and corneii (short body)

Front 83

Where are follicular mites found?

Back 83

NORMAL FLORA of canine hair follicle! Dz only when proliferate out of control (dysfxn Tcells, hereditary predis (spay/neuter!), role of immune supression

non-contagious

4 life stages: egg, larva, nymph, adult

Front 84

Demodicosis Dz categories

Back 84

Juvenile (<18mos) --> localized or generalized

-->red patches of alopecia on face and forelegs

Adult --> localized, generalized (pustular, squamous, pododemodicosis)

Front 85

Why distinguish localized vs. generalized demodicosis?

Back 85

affects Tx

local = <6 lesions
general= 12+ lesions OR on both feet OR envolves entire body region