Fungal Infections

Question 1

Which layer of skin does non-invasive cutaneous mycoses primarily affect?

Answer 1

(the epidermal layer)- cornified components of skin

Question 2

what does invasive mycoses result from?

Answer 2

direct penetration of epidermis, dermis and deeper tissue due to injury

Question 3

how does one acquire a systemic mycoses?

Answer 3

usually by a pulmonary infection

Question 4

what is the most common type of cutaneous mycoses?

Answer 4

non-invasive cutaneous mycoses: tinea capitis, tinea cruris, tinea pedis

Question 5

fungal infections follow one of two courses. describe the self-limited course.

Answer 5

acute inflammation and shorter lasting

Question 6

name the 3 different subgroups of noninvasive cutaneous infections.

Answer 6

1. superficial infections
2. dermatophyte infections
3. candidiasis

Question 7

Name the non-invasive superficial infections.

Answer 7

tinea versicolor
tinea nigra palmaris
piedra

Question 8

what is the causative organisms of tinea versicolor?

Answer 8

Pityrosporon orbicular (grows in sebaceous gland-rich areas of the skin)

Question 9

what are S/S of tinea versicolor?

Answer 9

• hypo or hyperpigmented macules that fail to tan with sun exposure
• mild itching exacerbated w/ sweating
• lesions on upper torso, neck and proximal UE

Question 10

how do you treat tinea versicolor?

Answer 10

antifungal shampoos

topical creams: ketoconazole

Question 11

what is the causative organism of tinea nigra palmaris?

Answer 11

C. werneckii

Question 12

what is tinea nigra palmaris?

Answer 12

fungus that infects the stratum corneum of the palms and soles without inflammatory reaction associated with it

Question 13

how do you treat tinea nigra palmaris?

Answer 13

(lesion scrapes off) so use keratolytic agents to exfoliate (Whitfield’s ointment, keralyte gel, 40% urea)

Question 14

what is a piedra?

Answer 14

a condition of the hair shaft characterized by firm irregular nodules composed of elements from the infecting organism

Question 15

what is the causative organism for a black piedra?

Answer 15

Piedraia hortai

Question 16

what is teh causative organism for a white piedra?

Answer 16

Trichosporon cutaneum

Question 17

Where is white piedra usually found? black piedra?

Answer 17

white piedra- SE USA

black piedra- tropical areas

Question 18

what is the most prevalent fungal infection?

Answer 18

tinea pedis

Question 19

what are the 4 types of tinea pedis?

Answer 19

1. interdigital
2. vesicular
3. chronic papulosquamous
4. ulcerative

Question 20

what is the causative organism(s) of interdigital tinea pedis?

Answer 20

Tricophyton Rubrum
or T. Mentagrophytes
(same for vesicular tinea pedis)

Question 21

what course does interdigital tinea pedis follow?

Answer 21

type a or b (self-limiting or chronic progressive)

Question 22

what course does vesicular tinea pedis follow?

Answer 22

type a (self-limiting)

Question 23

what is usually the causative organism of chronic papulosquamous tinea pedis?

Answer 23

T. Rubrum

Question 24

what course does chronic papulosquamous follow?

Answer 24

type b (chronic progressive course)

Question 25

what is the presentation of chronic papulosquamous (mocassin)?

Answer 25

minimally inflammatory | dull, erythema,dryness, scaling and hyperkeratosis affecting the plantar skin of both feet in a mocassin distribution

Question 26

what lab testings could you do to look for tinea pedis?

Answer 26

KOH prep | look at characteristics on Sabouraud agar

Question 27

which noninvasive cutaneous pathogen has the greatest pathologic potential?

Answer 27

cutaneous candidiasis

Question 28

what populations are affected by cutaneous candidasis?

Answer 28

diabetes | immunosuppressed

Question 29

s/s of cutaneous candidiasis?

Answer 29

burning, stinging and itching occurs in the intertriginous areas of the affected body part

Question 30

what are the clinical presentations of cutaneous candidiasis?

Answer 30

``` oral candidiasis (thrush) angular cheilitis ```

Question 31

name the invasive cutaneous mycoses.

Answer 31

chromoblastomycosis mycetoma sporotrichosis mucormycosis

Question 32

which species cause chromoblastomycosis?

Answer 32

fonesca phialophora cladosporium

Question 33

what is chromoblastomycoses?

Answer 33

fungi that grows as filamentous, saprophytic organisms in the soil, where they extra nutrients from decaying vegetation

Question 34

S/S of chromoblastomycoses

Answer 34

itching, warty papule that may progress to draining sinus tract and elephantiasis

Question 35

what will you see on KOH examination of chromoblastomycoses?

Answer 35

brown branching hyphae

Question 36

what are the causative organisms for Maduromycosis (mycetoma)?

Answer 36

allescheria boydii, madurella, phialophora | may also be cause by bacteria though

Question 37

what is the triad associated with maduromycosis (mycetoma)?

Answer 37

1. draining sinus tracts 2. discharge fluid containing granules that range in color 3. nodular tumorous, fibrotic swelling

Question 38

how do you treat actinomycotic infections?

Answer 38

Bactrim (TMP-SMX) or dapsone

Question 39

how do you treat eumycotic infections?

Answer 39

oral antifungals in conjunction with debridement tends to be unsuccessful-amputation is often required

Question 40

what is the causative organism of sporotrichosis?

Answer 40

Sporothrix schenckii

Question 41

what are the two types of sporotrichosis?

Answer 41

1. chancriform: tender, sometimes painful nodule on the finger or hand accompanied by lymphadenopathy 2. fixed cutaneous plaques- tender

Question 42

how do you treat chancriform sporotrichosis?

Answer 42

amphotericin B flucytosine ketoconazole

Question 43

how do you treat fixed cutaneous sporotrichosis?

Answer 43

amphotericin B

Question 44

name the systemic mycoses.

Answer 44

``` coccidiodomycosis histoplasmosis blastomycosis paracoccidioidomycosis cryptococcosis ```

Question 45

what are the causative organisms of the coccidioidomycosis?

Answer 45

C. Immitis, C. posadasii

Question 46

which systemic mycoses is endemic to Ohio and Mississippi river valley?

Answer 46

blastomycosis

Question 47

which systemic mycoses is paracoccidioidomycosis?

Answer 47

south american blastomycosis

Question 48

which systemic mycosis presents as oropharyngeal ulceration?

Answer 48

paracoccidioidomycosis

Question 49

what are the 4 pathological syndromes of aspergillus?

Answer 49

1. allergic bronchopulmonary aspergillosis 2. aspergilloma mycetoma 3. chronic necrotizing pulmonary aspergillosis 4. invasive aspergilllosis