Superficial Fungi part 1

Question 1

conidia

Answer 1

asexual nonmotile spores - reproductive structures
microconidia - trichophyton
macroconidia - microsporum, epidermophyton

Question 2

sporangia

Answer 2

spores produced in a sac

Question 3

chlamydoconidia

Answer 3

thick walled round cell

Question 4

blastoconidia

Answer 4

formed by budding

Question 5

arthroconidia

Answer 5

formed by fragmentation of hyphae

Question 6

tinea nigra organism & presentation

Answer 6

hortaea/exophiala werneckii
black yeast-like hyphomycete
hot humid environment
confined to SC (looks like lentigo on foot)

Question 7

tinea nigra dx and txt

Answer 7

golden brown hyphae on KOH (melanin)
older colonies grayish & filamentous
Rx: keratolytics (whitfield’s ointment), imidazoles

Question 8

black piedra organism? presentation? location?

Answer 8

piedra hortae
firmly adherent black nodules on hair
tropics, south america

Question 9

white piedra organism? presentation? culture?

Answer 9

trichosporon beigelii and T. inkin (pubic)
opportunistic - immunosuppressed
tan/white loosely adherent nodules along hair shafts

Question 10

trichosporanosis organism? presentation?

Answer 10

trichosporon asahii
systemic in immunocompromised
papulovesicular and purpuric lesions w/ necrosis

Question 11

tinea versicolor organism? cause of depigmentation? dx?

Answer 11

malassezia furfur (pityrosporum orbiculare is yeast phase)
dicarboxylic acid causes depigmentation
KOH: spaghetti and meatballs
wood’s light: yellow-green

Question 12

malassezia implicated in what neonatal skin condition

Answer 12

neonatal cephalic pustulosis (neonatal acne)

Question 13

pityrosporum folliculitis

Answer 13

wood’s light: yellow-green
KOH: only yeast seen
monomorphic follicular papules and pustules, often during acne txt (tetracycline casues overgrowth)
women, neck face & trunk
M. furfur and M globosa
fluconazole 400 mg x1 and 2.5% selenium sulfide

Question 14

how do dermatophytes escape immune system?

Answer 14

mannans

Question 15

how do dermatophytes infect SC, hair, nails

Answer 15

keratinases

Question 16

geophilic dermatophytes

Answer 16

mod-severe inflammation
Gypspies are Terrible F'ing Cooks
M. gypseum (tinea corporis, capitis)
T. terrestre
M. fulvum
M. cookei

Question 17

dermatophyte nutritional requirements

Answer 17

thiamine (tonsurans, violaceum, verrucosum)
histidine (megninii)
niacin (equinum)
inositol and thiamine (verrucosum)
olive oil (m. furfur)

Question 17

trichophyton

Answer 17

endothrix, no fluorescence

Question 17

trichophyton

Answer 17

endothrix, no fluorescence

Question 18

microsporum

Answer 18

ectothrix, +/- fluorescence

Question 18

microsporum

Answer 18

ectothrix, +/- fluorescence

Question 19

T. tonsurans

Answer 19

tinea capitis, tinea corporis
granular powdery front and mahogany reverse
pencil shaped swollen microconidia of varying size
cx: need thiamine

Question 19

T. rubrum

Answer 19

tinea unguium, corporis, capitis
powder puff front, red wine reverse
microconidia lined up like birds on a wire or plucked grape stem

Question 20

T. tonsurans

Answer 20

tinea capitis, tinea corporis
pencil shaped swollen microconidia of varying size
cx: need thiamine

Question 20

t. mentagorophytes

Answer 20

``` zoophilic white wooly front & orange reverse spiral (curly fry) hyphae urease + potato dextrose + hair perforation test + (t. rubrum -) ```

Question 21

t. soudanense

Answer 21

right-angle branching hyphae | ...39

Question 21

t. violaceum

Answer 21

...38

Question 21

t. soudanense

Answer 21

right-angle branching hyphae | ...39

Question 21

t. violaceum

Answer 21

...38

Question 22

T. rubrum

Answer 22

tinea unguium, corporis, capitis | microconidia lined up like birds on a wire or plucked grape stem

Question 23

t. verrucosum

Answer 23

cattle...40

Question 23

t. verrucosum

Answer 23

cattle...40

Question 24

t. concentricum

Answer 24

tinea imbricata pacific islands 'balloon shaped' chlamydoconidia and antler-like hyphae

Question 25

t. mentagorophytes

Answer 25

``` zoophilic spiral (curly fry) hyphae urease + potato dextrose + hair perforation test + (t. rubrum -) ```

Question 26

t. shoenleinii

Answer 26

``` tinea capitis (favus) endothrix favic chandeliers ```

Question 27

45

Answer 27

45

Question 28

m. canis

Answer 28

'dogs tail'

Question 29

m. audouinii

Answer 29

grey-tan front, orange salmon reverse. mouse fur | ...

Question 30

tinea capitis types

Answer 30

gray-patch ringworm - microsporum, endothrix black-dot ringworm - t. tonsurans & t. violaceum, endothrix. do not fluoresce kerion - m. canis & t. tonsurans. abscess, scarring alopecia, LAD favus - t. schoenleinii. scutulae sulfur yellow crusts. KOH w/ arthroconidia and airspaces within hair shaft

Question 31

m. nanum

Answer 31

pigs...

Question 32

m. gallinae

Answer 32

chickens..

Question 33

e. floccosum

Answer 33

tinea pedis, cruris khaki-colored colony w/ orange-brown reverse club-shaped macroconidia - NO microconidia (also macrosporum)

Question 34

dermatophyte test medium

Answer 34

dermatophytes produce alkaline = red | nondermatophytes produce acid = yellow

Question 35

wood's lamp

Answer 35

365 nm (lost in the woods for a year)

Question 36

Fluorescent positive infections

Answer 36

Cats And Dogs Fight and Growl Sometimes

Question 37

tinea capitis organism? presentation?

Answer 37

all trichophyton and microsporum (except t. concentricum and e. floccosum) MC: t. tonsurans (m. canis mc world-wide) 5-15% urban children asx'ly colonized can look like seb derm - scrape, alopecia

Question 38

tinea capitis pathogenesis?

Answer 38

incubation 2-4 days hyphae descent to form 'Adamson fringe" - level of keratinization hair breakage at 3 wks

Question 39

tinea capitis types

Answer 39

gray-patch ringworm - microsporum, endothrix | black-dot ringworm - t. tonsurans & t. violaceum, endothrix. do not fluoresce

Question 40

endothrix infections

Answer 40

Say Say Violet..67

Question 41

tinea capitis txt

Answer 41

griseofulvin, terbinafine with shampoo | treat household contacts (adults are carriers)

Question 42

tinea barbae

Answer 42

contact w/ farm animals deep - nodular & suppurative. t mentagrophytes superficial - crust w/ bald patches. t. violaceum or t rubrum DOES NOT AFFECT UPPER LIP

Question 43

tinea faciei

Answer 43

t. rubrum, t. mentagrophytes upper lip females & children looks like SLE - it is photosensitive! can have folliculitis - oral txt

Question 44

tinea corporis

Answer 44

MCC t. rubrum

Question 46

Ectothrix organisms

Answer 46

Dogs and Cats Fight Sometimes