Lecture: Dermatophytosis Flashcards Preview

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Flashcards in Lecture: Dermatophytosis Deck (31)
1

anamorph state

Dogs and Cats

  • microsporum canis
  • microsporum gypseum
  • trichophyton mentagrophytes
  • microsporum persicolor

2

anamorph state

horses

trychopyton equinum

3

anamorph state

cattle

trichophyton verrucosum

4

anamorph state

pigs

microsporum nanum

5

M. Canis

Reservoir

cats

6

M. gypseum

reservoir

soil

7

T. mentagrophytes

reservoir

rodents, rabbits, pocket pets

8

Dermatophytosis

Predisposing factors

  • lack/decreased grooming
  • presence of microtrauma
  • excessive hydration/maceration
  • warm temp and humidity
  • lack of sun exposure
  • strong cell-mediated immunity

9

Persians and himalayans

  • can be predisposed
  • asymptomatic carriers

10

Dermatophytosis

CS

  • variable
  • absent to moderate pruritus
  • muzzle and feets

11

alopecia in dermatophytosis

can be very well demarcated

12

Dermatophytosis horses

skin lesions around saddle and tack areas

pruritus

13

Dermatophytosis cattle

CS

  • severe scaling crusting
  • pain and pruritus variable

14

Kerion

  • Well circumscribed nodular mass
  • folliculitis to furunculotis
  • face, muzzle, feet

15

Dermatophytosis

DDX

  • parasitic diseases
  • allergies
  • pemphigus foliaceus
  • keratinization defects

16

Dermatophytosis

DX

  • Wood's lamp exam
  • trichogram evaluation
  • culture with microscopic ID

17

fungal culture

  • DTM
    • dermatophytes turn culture red in conjuction with growth
    • comtaminants do this too, but not in conjunction with growth

18

mackenzie technique

  • tooth brush entire animal (5 minutes....)
    • place tooth brush in medium

19

Dermatophytosis

TX considerations

  • eliminate infection from host
  • prevent dissemination
    • spores can persist in environment for 18 months
  • removal of spores from environment
  • dz is zoonotic
  • healthy animals can self-cure in 12-17 weeks

20

dermatophytosis

Therapeutic options

  • systemic therapy
  • topical therapy
  • environmental therapy
  • treat all animals in contact (just like scabies)

21

Dermatophytosis

topical therapy

  • ketaconazole
  • miconazole
  • chlorhexidine
  • lyme sulfur

*clipping hair vs not clipping hair

22

dermatophytosis

systemic therapy

  • ketaconazole
  • Itraconazole
  • Fluconazole
  • Terbinafine
  • Griseofulvin

23

griseofulvin

  • fungistatic
  • cheap
  • eat with fatty meal
  • only effective against dermatophytes (NOT YEAST)
  • Side effects
    • V/GI
    • bone marrow suppresion
    • viruses contraindicated (check FIV, FeLV)
    • teratogenic

24

ketoconazole

  • fungistatic
  • take with fatty meal
  • don't use with H2 antagonists
  • good efficacy against
    • M. canis
    • T. mentagrophytes
    • malassezia
  • Side effects
    • V/diarrhea
    • inc liver enzymes (not assoc with clinical signs)
    • intereferes with cytochrome P450
  • tolerated by dogs
  • probs not great in cats
  • Not in pregnant animals

25

Itraconazole

  • fungistatic (low doses)
  • fungicidal (high doses)
  • preferred for feline fungal infections
  • take with fattty meal
  • expensive
  • side effects
    • uncommon
  • not recommended with dogs with vasculitis or preggos

26

fluconazole

  • fungistatic
  • broad antimycotic spectrum
  • little hepatic metabolism
  • recommended in patients with liver disease

27

terbinafine

  • fungicidal
  • pulse therapy
  • few side effects
  • no P450 stuff

28

environmental decontamination

  • Swiffer/vacuum
  • Detergent
  • Bleach
  • Enilconazole

*wash everything twice

29

duration of therapy

  • no growth on two sequential weekly cultures
    • finalized after 14 days
  • or 2 negative cultures one month apart

30

Onychomycosis

(infection of the nails)

  • prognosis for cure is guarded (tx 6-12 months) if at all
  • Itraconazole and terbinafine are best agents
    • stay in keratinized tissue

31

Large animal therapy

  • Infections usually self limiting
  • exposure to sun helps
  • topical therapy
    • lyme sulfur (till 2 weeks past clinical cure)