Lecture: Dermatophytosis Flashcards
anamorph state
Dogs and Cats
- microsporum canis
- microsporum gypseum
- trichophyton mentagrophytes
- microsporum persicolor
anamorph state
horses
trychopyton equinum
anamorph state
cattle
trichophyton verrucosum
anamorph state
pigs
microsporum nanum
M. Canis
Reservoir
cats
M. gypseum
reservoir
soil
T. mentagrophytes
reservoir
rodents, rabbits, pocket pets
Dermatophytosis
Predisposing factors
- lack/decreased grooming
- presence of microtrauma
- excessive hydration/maceration
- warm temp and humidity
- lack of sun exposure
- strong cell-mediated immunity
Persians and himalayans
- can be predisposed
- asymptomatic carriers
Dermatophytosis
CS
- variable
- absent to moderate pruritus
- muzzle and feets
alopecia in dermatophytosis
can be very well demarcated
Dermatophytosis horses
skin lesions around saddle and tack areas
pruritus
Dermatophytosis cattle
CS
- severe scaling crusting
- pain and pruritus variable
Kerion
- Well circumscribed nodular mass
- folliculitis to furunculotis
- face, muzzle, feet
Dermatophytosis
DDX
- parasitic diseases
- allergies
- pemphigus foliaceus
- keratinization defects
Dermatophytosis
DX
- Wood’s lamp exam
- trichogram evaluation
- culture with microscopic ID
fungal culture
- DTM
- dermatophytes turn culture red in conjuction with growth
- comtaminants do this too, but not in conjunction with growth
mackenzie technique
- tooth brush entire animal (5 minutes….)
- place tooth brush in medium
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
dermatophytosis
Therapeutic options
- systemic therapy
- topical therapy
- environmental therapy
- treat all animals in contact (just like scabies)
Dermatophytosis
topical therapy
- ketaconazole
- miconazole
- chlorhexidine
- lyme sulfur
*clipping hair vs not clipping hair
dermatophytosis
systemic therapy
- ketaconazole
- Itraconazole
- Fluconazole
- Terbinafine
- Griseofulvin
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
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
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
fluconazole
- fungistatic
- broad antimycotic spectrum
- little hepatic metabolism
- recommended in patients with liver disease
terbinafine
- fungicidal
- pulse therapy
- few side effects
- no P450 stuff
environmental decontamination
- Swiffer/vacuum
- Detergent
- Bleach
- Enilconazole
*wash everything twice
duration of therapy
- no growth on two sequential weekly cultures
- finalized after 14 days
- or 2 negative cultures one month apart
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
Large animal therapy
- Infections usually self limiting
- exposure to sun helps
- topical therapy
- lyme sulfur (till 2 weeks past clinical cure)
