Micro - Fungal

Question 1

Define Dimorphic

Answer 1

Yeast at 37 C (body temp), mold at room temp

Question 2

Define DermatoPHYtoses

Answer 2

infect skin, hair, and nails

Question 3

Define DermatoMYCoses

Answer 3

Invasive fungal infections of the skin. Includes primary and secondary colonizations

Question 4

Define Dematiaceous fungi

Answer 4

Hyphae and/or spores darkly pigmented

Question 5

Malassezia species Mycosis

Answer 5

Pityriasis versicolor

Superficial fungi

Question 6

Hortaea werneckii Mycosis:

Answer 6

Tinea nigra

Superficial fungi

Question 7

Trichosporon spp Mycosis:

Answer 7

White piedra

Superficial fungi

Question 8

Piedraia hortae Mycosis:

Answer 8

Black Piedra

Superficial fungi

Question 9

Malassezia furfur/Pityriasis versicolor lab tests

Answer 9

Dimorphic, Lipophilic (grow on solid media overlaid with olive oil)
Requires LONG-chain fatty acids for growth

Question 10

Oval scaly macules/papules. Hypo/Hyper pigmentation
Patches where sebaceous glands present
Fluoresces bright yellow with wood lamp
Short, unbranched hyphae with round spores (KOH)
“Spaghetti and meatballs”

Answer 10

Malassezia furfur aka Pityriasis versicolor

Question 11

Branched septate hyphae and budding yeast cells with melanized cell walls. A Dermatiaceous fungus.
Brownish to grey patches on palms or soles

Answer 11

Hortae (Exophialia) werneckii

Question 12

Soft (ish) white nodules on hair (hyphae when crushed)

Urease positive

Answer 12

Trichosporon spp - White piedra

Question 13

Ectotrhix

Answer 13

Stone-like formation on scalp and facial hair (NOT genital) - Piedraia hortae - BLack piedra

Question 14

Cutaneous fungi (Microsporum spp, TrichoPHYton spp, and Epidermophyton floccosum) all cause:

Answer 14

Dermatophytosis (ring worm)

Question 15

Virulence factor of Tineas

Answer 15

Keratinases

Question 16

Tinea corporis: Location

Answer 16

Nonhairy, smooth skin, Trunk

Question 17

Tinea corporis: Clinical features

Answer 17

Circular patches with advancing red, vesiculated border and central scaling, pruritic

Question 18

Fungi responsible for Tinea corporis

Answer 18

T. Rubrum *

E. Floccosum

Question 19

Tinea Pedis: Location

Answer 19

Interdigital spaces on feet

Question 20

Tiena pedis: Clinical features

Answer 20

Acute: Itching, red, vesicular
Chronic: itching, scaling fissures
“Athletes foot” - men, wearing shoes

Question 21

Fungi responsible for Tinea pedis

Answer 21

*T. Rubrum
T. Mentagrophytes
E. Floccosum

Question 22

Tinea cruis: location

Answer 22

Groid

Question 23

Tinea cruis: Clinical

Answer 23

Erythematous scaling lesion in intertriginous areas, pruritic

Question 24

Tinea cruis: Fungi responsible

Answer 24

*T. Rubrum
T. Mentagrophytes
E. Floccosum

Question 25

Tinea cruris differential: Erythrasma

Answer 25

Caused by Corynebacterium minutissimum

Fluoresces coral red (T. cruis does NOT fluoresce)

Question 26

Tiena cruris differential: Candida

Answer 26

Affects skin ON scrotum and thick

T. cruis begins on skin opposite of scrotum - not ON the scrotum itself

Question 27

Tinea infections - Hyphae location (histo level)

Answer 27

Stratum corneum

Question 28

Tinea capitis: Location, clinical features, Fungi responsible

Answer 28

Scalp hair
Circular bald patches w/short hair stubs or broken hair w/I hair follicles
Most common in US: T. Tonsurans (T. Mentagrophytes, M. Canis)

Question 29

Tinea Barbae: Location, Clinical, Fungi responsible

Answer 29

Beard Hair
Edematous, erythematous lesions
T. Mentagrophytes

Question 30

Tinea Unguium “Onychomycosis”

Location, Clinical features, Fungi responsible

Answer 30

Nail
Nails thickened or crumbling distally, discolored, lusterless
T. rubrum, T. mentagrophytes, E. Floccosum

Question 31

Dermtophytid “id Reaction”

Location, Clinical features, Fungi responsible

Answer 31

Usually sides and flexor aspects of fingers
Pruritic vesicular to bullous lesions; Most commonly associated with tinea pedis
Fungi responsible: NO fungi in lesion

Question 32

Which cause of tinea capitis fluoresce under Wood’s Lamp

Answer 32

Microsporum (Trichophyton does NOT)

Question 33

What is a Kerion?

Answer 33

Intense, painful, boggy, suppurative reaction associated with cervical lymphadenopathy.
Found at the nape of the neck

Question 34

What is needed to control Candida

Answer 34

T-cell response

Question 35

Sprothrix schenckii. Mycosis =?

Answer 35

Sporotrichosis

Question 36

Phialophora Verrucosa

Fonsecaea pedrosoi. Mycosis =?

Answer 36

Chromoblastomycosis

Question 37

Pseudallescheria boydii

Madurella mycetomatis Mycosis =?

Answer 37

Mycetoma

Question 38

Exophiala
Bisporais Mycosis = ?
Exserohilum

Answer 38

Phaeohyphomycosis

Question 39

“Drunken rose gardener’s disease”
Initial lesion = papule
Follows LYMPHATICS - CHAIN OF NODULES

Answer 39

Sporothrix schenkii

Dimorphic fungus

Question 40

Local swelling

Interconnecting sinuses that contain granules (granules = microcolonies of the agent embedded in tissue)

Answer 40

Mycetoma

Question 41

Mycetoma colors and significance

Answer 41

White: P. boydii
Black: M. grisea, E. jeanselmei
Dark red - black: M. mycetomatis

Question 42

Tropics
Feet exposed to infected soil
Warty, friable granuloma on leg
“Cauliflower like”
Starts as smooth papule, then becomes verrucous lesion
Pustules may contain pigmented fungal cells (MEDLAR BODIES)

Answer 42

Chromoblastomycosis