Fungal Diseases Flashcards
What are fungi?
Eurkaroytic Unicellular or filamentous multicellular Most non-flagellate Nutritionally absorptive Cell walls contain chitin and beta-glucans Reproduce asexually or sexually
What is Malassezia?
A yeast: unicellular budding fungus
What are the clinical signs of dermatophytosis?
Variable Circular/annular lesions Scaling, crust, erythema, alopecia Diffuse scaling Nodules/ulceration Asymptomatic carriers
What can dermatophytosis in cats cause?
Folliculised furunculosis and progression into the deep dermis and subq tissues causing granulomatous reaction
How do you diagnose dermatophytosis?
Skin scraping/hair plucks
Wood’s lamp
Fungal culture
Skin biopsies
How do you test for dermatophytosis with Wood’s lamp?
Darkened room
Shine lamp over haircoat
Apple-green fluorescence on hair
Trichophyton spp. do not fluoresce
How do you culture for dermatophytosis?
Pluck hairs and pull off scales with forceps
Sabourand’s dextrose agar with chloramphenicol and cycloheximide
Incubate at 26C for 4 weeks
What is the therapy available for dermatophytosis?
Environmental decontamination Clipping haired skin Topical - Enilconazole (dog, cattle, horse) - Miconazole, Chlorhexidine or Lime Sulphur (cat) Systemic Itraconanazole Griseofulvin
Is there a vaccination for ringworm?
Yes - Bovillis Ringvac live attenuated T. verrucosum very effective but costly
What is the only Malassezia which will grow on dextrose agar?
Malassezia pachydermatitis as it is non lipid-dependent
What are the clinical signs of malassezia dermatitis?
Pruritus Erythema with/without papules Scaling Greasy exudation Hyperpigmentation Malodour
What diseases may Malassezia complicate?
Allergy
Ectoparasite infection
Keratinisation defects
May occur with staphylococcus in which case AB needed
Which breed of dog is predisposed to Malassezia?
Basset hound can have large numbers present without disease
How do you assess skin Malassezia populations?
Cytology
- Tape strip
- Direct impression
- Skin scraping
Culture
- Swab
- Contact plate
- Detergent scrub
How do you treat malassezia?
Topical
- Miconazole/Chlorhexidine (malaseb)
- Chlorhexidine (Pyohex)
Systemic
- Itraconazole
