Skin VII

Question 1

list the 3 members of dermatophytes

Answer 1

• Epidermophyton spp.
• Microsporum spp.
• Trichopyhton spp.

Question 2

dermatophytes are spread via ____

why is this significant?

Answer 2

dermatophytes are spread via peron-to-person contact

fungi are usually inhaled but this is an exception

Question 3

diagnosis of dermatophytes is skin/hair/nail scraping cultured on ____

Answer 3

diagnosis of dermatophytes is skin/hair/nail scraping cultured on Mycosel agar

Question 4

70% of Trichophyton cases are ____

Answer 4

70% of Trichophyton cases are athlete’s foot (Trichophyton rubrum)

Question 5

why is Microsporum, macroconidia significant?

Answer 5

they are positive for the 3 tests:

hair perforation test +

fluorescence +

urea +

Question 6

what fungus is implicated in a vignette that has “sleeping with a dog,” or “got a dog recently”?

Answer 6

Microsporum canis

Question 7

Answer 7

“spindle/lancet-shaped”

Question 8

describe the image

Answer 8

“Beaver tail”

Question 9

describe the image

Answer 9

parallel-shaped macroconidia

Question 10

describe the image

Answer 10

“birds on a line”

Question 11

the most common cause of Tinea versicolor is ____

Answer 11

the most common cause of Tinea versicolor is Malassezia furfur

Question 12

M. furfur produces hypopigmented plaques by inhibiting ___

Answer 12

M. furfur produces hypopigmented plaques by inhibiting tyrosinase

Question 13

what causes the condition seen in the image?

Answer 13

M. furfur

Question 14

diagnosis of the condition seen in the image is via ___

Answer 14

diagnosis is via KOH preparation, which shows short hyphae and spores with a spaghetti-and-meatballs appearance

Question 15

Answer 15

Question 16

treatment of Tinea versicolor is with ____

Answer 16

treatment of Tinea versicolor is with Selenium sulfide shampoo

Question 17

the cause of Tinea nigra is ____

Answer 17

the cause of Tinea nigra is Hotaea werneckii

Question 18

Tinea nigra appears as a brownish spot caused by ____

Answer 18

Tinea nigra appears as a brownish spot caused by melanin-like pigment in the hyphae

Question 19

Tinea nigra appears as a ____ spot caused by the melanin-like pigment in the hyphae

Answer 19

Tinea nigra appears as a brownish spot caused by the melanin-like pigment in the hyphae

Question 20

black and white piedra is caused by fungal infection of ____

Answer 20

black and white piedra is caused by fungal infection of the hair shaft

Question 21

the nodules in black and white piedra are ___ and ___ of the fungus (____)

Answer 21

the nodules in black and white piedra are hyphae and fruiting bodies of the fungus (ascostroma)

Question 22

black piedra is caused by ____ and ____

Answer 22

black piedra is caused by Piedraia hortae and Trichosporon ovoides

Question 23

white piedra is caused by fungi in the ____ genus

Answer 23

white piedra is caused by fungi in the Trichophyton genus

Question 24

in black and white piedra, ___ and ___ are potentially life-threatening in immunocompromised patients

Answer 24

in black and white piedra, Trichosporon asahii and T. inkin are potentially life-threatening in immunocompromised patients

Question 25

chromoblastomycosis is caused by \_\_\_\_

Answer 25

chromoblastomycosis is caused by **Dematiaceous fungi**

Question 26

describe the presentation in chromoblastomycosis

Answer 26

a verrucous, slow-growing **nodule** present as **large brown spherical bodies (chromo bodies) in the dermis**

Question 27

in labs, chromoblastomycosis is seen as dark brown, round fungal balls in ___ or \_\_\_\_

Answer 27

in labs, chromoblastomycosis is seen as dark brown, round fungal balls in **leukocytes** or **giant cells**

Question 28

the transmission of chromoblastomycosis is via \_\_\_\_

Answer 28

the transmission of chromoblastomycosis is via **traumatic implantation**

Question 29

the condition seen in the image extends along \_\_\_\_

Answer 29

**chromoblastomycosis** extends along **the lymphatics**

Question 30

the condition seen in the image is a slowly progressive, ____ infection that is caused by fungi when introduced into the skin through trauma

Answer 30

**chromoblastomycosis** is a slowly progressive, **granulomatous** infection that is caused by fungi when introduced into the skin through trauma

Question 31

sporotrichosis is caused by \_\_\_\_

Answer 31

sporotrichosis is caused by **Sporothrix schenckii**

Question 32

sporotrichosis is also called \_\_\_\_

Answer 32

sporotrichosis is also called **"rose gardener's disease"**

Question 33

sporotrichosis spreads/follows the \_\_\_

Answer 33

sporotrichosis spreads/follows the **lymph**

Question 34

describe the 2 presentations in the lab of sporotrichosis

Answer 34

Question 35

transmission of sporotrichosis is commonly associated with....

Answer 35

transmission of sporotrichosis is commonly associated with: ## Footnote **splinters** **thorns** **moss** **mulch** **hay**

Question 36

Answer 36

Question 37

Candidiasis causes \_\_\_\_

Answer 37

Candidiasis causes **oral thrush, cutaneous candidiasis, vaginitis**

Question 38

describe the lab test performed on Candida

Answer 38

* tissue specimen: 10% KOH * culturing on selective and differential yeast media (i.e. tryptan blue media) * Candida appears light blue

Question 39

diagnosis of Candidiasis is by observing ____ and ____ in specimen

Answer 39

diagnosis of Candidiasis is by observing **budding yeast cells** and **pseudohyphae** in specimen

Question 40

dimorphic fungi are : yeast at ____ degrees C mold at ____ degrees C

Answer 40

yeast at **37** degrees C mold at **25** degrees C