Antifungal Drugs & Fungal Skin Infections

Question 1

Define a:

Single cell, spherical or elliptical fungi

If it reproduces by budding it is a?
If the bud stays attached it forms?

Answer 1

Yeast

Blastoconidia

Pseudohyphae

Question 2

Defina a multicellular fungi.

If forms thread like filaments called?

Answer 2

Mold

Hyphae

Question 3

A mass of hyphae

Answer 3

Mycelium

Question 4

Fungi that has both yeas and mold form is?

Answer 4

Dimorphic fungi

Mold - Cold (environment)
Yeast - Heat (body)

Question 5

Produced from sexual reproduction

Produced from asexual reproduction

Answer 5

Spore

Conidia

Question 6

Hyphae on parasitic fungi

Answer 6

Haustoria

Question 7

What anti fungal is used for invasive systemic fungal infections in immunocompramized patients?

It is active against yeast and molds

Answer 7

Poleyens: Amphotericin B and Nystatin (topical)

Question 8

What is the mechanism of action of the polyenes?

Answer 8

Bind to ergosterol

Fungicidal

Question 9

What antifungals are nephrotoxic?

Answer 9

Amphotericin B

Question 10

What anti fungal is most widely used and the spectrum varies by agent?

Answer 10

Azoles: Fluconazole, Itraconazole, Ketoconazole

DO NOT CONFUSE with metronidazole (antibacterial)

Question 11

What is the mechanism of action of the Azoles?

Answer 11

Binds fungal P450 enzymes (ERG11), blocks production of ergosterol, causes accumulation of Ianosterol

Fungistatic

Question 12

What antifungals to avoid during pregnancy

Answer 12

Azoles

Griseofulvin

Question 13

What antifungals are hepatotoxic?

Answer 13

Azoles

Question 14

What antifungals are neurotoxic?

Answer 14

Azoles

Question 15

What antifungals are used on dermatophytes?

Answer 15

Allylamines - Terbinafine (lamisil) (Topical)

Griseofulvin

Question 16

What is the mechanism of the allylamines?

Answer 16

Terbinafine (Lamisil)

Inhibits squalene epoxidase, accumulation of toxic squalene

Fungicidal

Question 17

What antifungals interact with drugs which are broken down by CYP2D6 enzymes

Answer 17

Allylamines - Terbinafine (lamisil)

Question 18

What anti fungal is used to treat Yeasts including Candida albicans and Cryptococcus?

Answer 18

Flucytosine (5-FC)

Question 19

What is the mechanism of 5-FC

Answer 19

Flucytosine

Nucleic Acid Synthesis Inhibitor

Converted to 5-Fluorouracil in fungi - inhibits both RNA and DNA synthesis

Fungistatic

Question 20

What anti fungal can lead to bone marrow suppression

Answer 20

5-FC

Question 21

What two antifungals are used together to reduce resistance and and increase uptake?

Answer 21

Flucytosine (5-FC) and Amphotericin B

Question 22

What is the mechanism of action of Griseofulvin?

Answer 22

Binds microtubules and inhibits spindle leading to multinucleate cells.. Fungistatic

Question 23

What anti fungal is teratogenic?

Answer 23

Griseofulvin

Question 24

What anti fungal is used to treat Candida Albicans?

Answer 24

Echinocandins - Caspofungin

Question 25

What is the mechanism of action of Caspofungin?

Answer 25

Cell wall inhibitor - blocks synthesis of beta flu can polysaccharide Fungicidal in candida Fungistatic in Aspergillus

Question 26

What antifungals do not cross the CNS barrier?

Answer 26

Azoles (fluconazole, Itraconazole, Ketoconazole) Echinocandins (caspofungin)

Question 27

Fungus that grows on or in the individual

Answer 27

Mycosis

Question 28

Poisoning from toxins made by a fungus

Answer 28

Mycotoxicoses

Question 29

What fungi cause hypersensitivity reactions?

Answer 29

Molds or spores

Question 30

What fungi cause cutaneous fungal infections?

Answer 30

Malassezia (tinea versicolor) Dermatophytes - Microsporum, Epidermophyton, Trichophyton

Question 31

What causes subcutaneous fungal infections? (Infection through the skin that is followed by a subcutaneous and/or lymphatic spread

Answer 31

Sporothrix

Question 32

What type of individuals are infected by fungi? What is most commonly the culprit in these individuals?

Answer 32

Immunocompramised. Fungi are opportunistic. Candida

Question 33

Common method to diagnose fungal infections of the skin?

Answer 33

Collect sample (skin, nail, hair) Dissolve in 10% KOH and stain View under 40X microscope

Question 34

What is a UV-A light which some Fungi fluoresce called?

Answer 34

Woods Lamp PCR and Culture

Question 35

What is the microbe and the disease in which hypo pigmentation or hyper pigmentation occurs in areas of high lipid content (sebaceous glands) in individuals 15-24 years old?

Answer 35

Tinea Versicolor Microbe is Malassezia Furfur Yeast is part of normal flora but is converted to the mold form in the disease

Question 36

What is fungi associated with seborreic dermatitis, scaly (cradle cap) and Tinea Versicolor?

Answer 36

Malassezia "spagetti and meatblass" under scope Treatment for seborreic dermatitis is topical therapy - selenium sulfide or ketoconazole shampoo

Question 37

What are the fungi associated with dermatophytoses - ringworm, tinea, jock itch, althetes foot?

Answer 37

Trichophyton Microsporum Epidermophyton Treat with topical antifungals or oral if nail infection

Question 38

What are the following bodily areas: ``` Capitis Barbae Axillaris Corporis Cruris Pedis Unguium Onychomycosis ```

Answer 38

``` Tinea capitis - Skull Tinea barbae - Beard Tinea axillaris - Armpit Tinea corporis - Body Tinea cruris - Groin Tinea pedis - Foot Tinea unguium - Nail (onychomycosis) ```

Question 39

Infection that most commonly causes tinea pedis - serpentine lesion with central clearing (anthropholic) occurs on moist areas of skin and carried on clothing (fomite transmission)

Answer 39

Trichophyton Rubum

Question 40

What fungi can cause hair and skin infections and fluoresces blue-green under a Woods Lamp? If transferred zoophilically it is? Geophilically?

Answer 40

Microsporum Canis Microsporum Fulvum