Dermatophytosis Flashcards
Dermatophytes invade what type of tissue?
Non-viable, keratinized tissue
What stage of hair growth do dermatophytes invade?
Anagen
What are the clinical features associated with dermatophytosis?
- Alopecic areas
- Erythema
- Crusts
- Scaling
- Hyperpigmentation
- Broken hairs
- Mild to moderate pruritus
What is furunculosis?
Open, draining tracts with serosanguinous fluid
What are the 3 most common causes of furunculosis?
- Bacteria
- Demodex
- Dermatophytes
What is the most definitive, sensitive test for dermatophytosis?
Fungal culture
What are your systemic therapy options for dermatophytosis?
- Azoles
- Griseofulvin
- Lufenuron
- Terbinafine
What are the potential side effects of griseofulvin?
- Teratogenesis
- GI disturbance
- Anorexia
- Bone marrow suppression
What is the mechanism of action of the azoles?
Inhibit lanosterol-14 alpha-demthylase, which is responsible for forming ergosterol, a component of the fungal cell wall.
What are the potential side effects associated with Ketoconazole?
- Anorexia
- Diarrhea
- Weight loss
- Increased hepatic enzyme concentrations
- Alopecia
Why does Ketoconazole have a lot of adverse interactions with other drugs?
It inhibits the P-glycoprotein efflux pump (brain, liver, GI)
True or False: Ketoconazoles penetrates readily into areas such as the CNS, eyes, and prostate.
FALSE - they penetrate these areas poorly
Which of these drugs is best given with a meal to increase absorption: Ketoconazole or Griseofulvin?
BOTH
What is the mechanism of action of Itraconazole?
Inhibits ergosterol synthesis
Is Itraconazole fungistatic or fungicidal?
Fungistatic
What are the adverse effects associated with Itraconazole?
- Vomiting
- Anorexia
- Increased hepatic enzyme concentrations
Which of the following should be avoided in pregnant animals: Ketoconazole, Griseofulvin, or Itraconazole?
Griseofulvin & Itraconazole
Which of the following is classified as a triazole: Ketoconazole, Itraconazole, Griseofulvin, or Fluconazole?
Itraconazole & Fluconazole
Which of the following is the best for penetration into tissues such as the CSF, eye, and claws: Ketoconazole, Itraconazole, Griseofulvin, or Fluconazole?
Fluconazole
What are the adverse effects associated with Fluconazole?
- Increased hepatic enzymes
2. Teratogenesis
Is Terbinafine fungistatic or fungicidal?
Fungicidal
What is the mechanism of action of Terbinafine?
Inhibits squalene epoxidase necessary for ergosterol synthesis.
What are the side effects associated with Terbinafine?
Relatively few side effects: elevated ALT concentration in 1/3 of cats treated.
Is Dermatophytosis contagious?
YES
Is Dermatophytosis infectious?
YES
Is Dermatophytosis zoonotic?
YES
