4: Fungal Infections of Skin - Bennett

Question 1

tinea =

Answer 1

refers to all noninvasive cutaneous mycoses expect those caused by candida species (candidiasis)

Question 2

tinea versicolor, tinea nigra palmaris and piedra proliferate only in…

Answer 2

stratum corneum

Question 3

tinea versicolor

Answer 3

• pityrosporon orbicular

- grows in sebaceous gland-rich areas of skin

Question 4

• hypo/hyperpigmented macules that fail to tan with sun exposure
• mild itching
• forearms, face, scalp, upper torso, neck, upper extremities

Answer 4

tinea versicolor

tx: antifungal shampoos (selenium disulfide, zinc pyrithione) topical ketoconazole

Question 5

tinea nigra palmaris

Answer 5

• c. werneckii

- slow spread within stratum corneum in palms/soles

Question 6

single brownish to black macule on the palms or soles

sharply marginated and non-scaly

Answer 6

tinea nigra palmaris

tx: removal of lesion by scraping, keratolytic agents, itraconazole, terbinafine

Question 7

hair nodule appears black

Answer 7

piedraia hortai (tropical environments)

Question 8

hair nodule appears white

Answer 8

trichosporon cutaneum (southern united states)

Question 9

treatment for piedras

Answer 9

remove infected hairs by cutting or shaving
black also oral terbinafine
white - topical antifungals

Question 10

pathogenesis of dermatophyte infections

Answer 10

• once skin is colonized, dermatophyte hyphae peentrate into stratum corneum and migrate deep until granular layer is reached
• spread laterally

Question 11

most prevalent fungal infection

Answer 11

tinea pedis

Question 12

interdigital tinea pedis

Answer 12

t. rubrum or t. mentagrophytes

- does not spread beyond intertriginous confines

Question 13

intensely inflammatory with vesicles and bullae in foci or clusters on foot (type A)

Answer 13

vesicular tinea pedis (caused by any dermatophyte)

Question 14

dull, erythema, dryness, scaling andhyperkeratosis affecting entire plantar skin of both feet in moccasin distribution

Answer 14

chronic papulosquamous
(mocassin) tinea pedis

t. rubrum organism

Question 15

sabouraud agar findings for dermatophytes

Answer 15

trichophyton rubrum - white cotton, red

trichonphyton mentagrophytes - white cotton, or cream to tan powder

epidermonphyton floccosum - fuzzy, tan, yellow or green

Question 16

greatest pathogenic potential of noninvasic cutaneous pathogens

Answer 16

cutaneous candidiasis

Question 17

describe cutaneous candidiasis

Answer 17

• intertriginous areas
• diabetes, antibiotics, corticosteroids, immunosuppressive meds
• occlusion and moisture in intertriginous areas
• colonization from host’s own GI or mucosal sources

Question 18

beefy red, scalded skin with irregular margin and satellite pustules

Answer 18

cutaneous candidiasis

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

Question 19

name 4 invasive cutaneous mycoses (infections that begin at point of focus w/i the skin, secondary to trauma or a foreign object might have penetrated the skin)

Answer 19

• chromoblastomycosis
• mycetoma
• sporotrichosis
• mucormycosis

Question 20

causative agent chromoblastomycosis

Answer 20

fonseca
philaphora
cladosporium

Question 21

itchy, warty papule, warty sores

may progress to foul smelling plaque, palm size

Answer 21

chromoblastomycosis

mycologic culture and biopsy are confirmatory (brown branching hyphae)

Question 22

causative organism mycetoma/maduromycosis

Answer 22

allescheria boydii, madurella, phialophora

Question 23

mycetomas caused by true fungi =

Answer 23

maduromycosis or eumycotic mycetoma
tx with oral antifungals and amputation

caused by bacteria = actinomycotic
tx with bactrim or dapsone

Question 24

triad of mycetomas

Answer 24

• sinus tracts draining to skin infection
• discharge fluid containing granules that range in color from white, tan, red or black
• nodular tumorous, fibrotic swelling

Question 25

chancriform

Answer 25

tender, sometimes painful nodule on the finger or hand accompanied by lymphadenopathy

sign sporotrichosis

Question 26

systemic mucoses essentially all begin in …

Answer 26

lung

Question 27

5 common systemic mycoses

Answer 27

• coccidioidomycosis
• histoplasmosis
• blastomycosis
• paracoccidioidomycosis
• cryptococcosis

Question 28

primary pulmonary infection with flu symptoms

also develop erythema multiforme or erythema nodosum

Answer 28

s/s coccidiomycosis

tx w/ ketoconazole, itraconazole, fluconazole, amp B

Question 29

verrucous papule, nodule or plaque on face, neck or upper torso

man 30-50

endemic to ohio and mississippi river valley

Answer 29

blastomycosis

tx w/ amp b, ketoconazole, KI

Question 30

south american blastomycosis

Answer 30

paracoccidiodiomycosis

Question 31

oropharyngeal ulceration

pain, distress secondary to papules, nodues and verrucous plaques

Answer 31

paracoccidiodiomycosis

tx: sulfonamides and amp B, ketoconazole

Question 32

variety of morphological lesions including abscesses, tumor-like masses, draining sinuses, panniculitis, etc in immunocompromised ppl

Answer 32

cryptocococcosis

tx w/ amp B, oral flucytosine, fluconazole

Question 33

assoc with bird and bat feces

Answer 33

histoplasmosis

primarily a pulmonary infection with chronic ulcerative lesions of mucosal surface

Question 34

4 pathological syndromes of aspergillus

Answer 34

allergic bronchopulmonary aspergillosis

aspergilloma mycetoma

chronic necrotizing pulmonary aspergillosis

invasive aspergillosis