Mycology Exam Ii: Superficial Mycoses

Front 1

define superficial mycoses

Back 1

-infection generally confined to the outer layers of the stratum corneum of skin or the cutilce of the hair shaft
-no significant direct immune response, no physical discomfort

Front 2

Name two superficial fungal pathogens that infect the outer layers of the stratum corneum of the skin

Back 2

Malassezia furfur and Exophiala werneckii

Front 3

Describe Malassezia furfur
classificant?
commensal?
environment?

Back 3

Basidiomycete, commensal, liphophillic

Front 4

Describe Malassezia furfur morphology

Back 4

dimorphic fungus with spherical to ellipsoidal budding yeasts and short hyphae, "spaghetti and meatballs" apperance
regulation of dimorphism is poorly understood

Front 5

What 5 clinical syndromes are associated with Malassezia furfur

Back 5

1. Tinea/ pityriasis versicolor
2. Dandruff
3. Folliculitis
4. Seborrheic dermatitis
5. IV catheter associated sepsis

Front 6

Describe the tinea/ pityriasis versicolor associated with Malassezia furfur

Back 6

-area of hyperpigmentation
-genearlly chronic
-localized to back, trunk, limbs, face
-more common in adolescents
-heat and moisture contribute
-dust like scales
-asymptomatic

Front 7

How can you diganose the tinea/ pityriasis associated with Malassezia furfur

Back 7

Wood's lmap or KOH or methylene blue stain of scales

Front 8

Describe the seborrheic dermatitis associated with Malassezia furfur infection

Back 8

-fungal invovlement controversial
-inflammation of sebaceous skin
-frequently involves face
-increased incidence in AIDs pts

Front 9

Describe the IV catheter associated sepsis associated with Malassezia furfur

Back 9

-rae but serious disseminated disease in infants receiving lipid emulsions containing concentrated essential lipids

Front 10

What clinical syndrome is associated with Exophiala wreneckii

Back 10

tinea negra
-E. wreneckii is a dematiaceous mold
-sxs include chronic dermatitis localized to palms of hands and soles of feet
-flat, brown or black patches with irregular pigmentation
-restricted to SE Asia, Africa, tropical Americas

Front 11

Which superficial mycoses is often confused for melanoma

Back 11

Exophiala wreneckii

Front 12

Name two superficial fungi that infect the cuticle of the hair

Back 12

1. Trichosporon beigelii
2. Piedraia hortai

Front 13

Name the causitive agent of white piedra and discribe the disease

Back 13

-caused by Trichosporon beigelii
-asymptomatic mold infection of the beard occuring in S. America, Euproe, Japan
-light colored soft, loosely attached nodules occur on the hairs and may cause breakage

Front 14

Name the causitive agent of black piedra and describe the disease

Back 14

-Piedraia hortai
-asxs mold infection of scalp in S. America and SE Asia
-dark brown or black gritty, firmly attached noduels occur on the hairs
-metallic whistling sound when combed

Front 15

this pathogen causes nodules that make a metallic whistling sound when combed

Back 15

Piedraia hortai

Front 16

What are the three genera of fungi that cause cutaneous mycoses (localized to nonliving keratinized layers but deeper than superficials)

Back 16

Epidermophyton, Microsporum, Trichophyton

Front 17

How are the cutaneous mycoses classified

Back 17

Geophilic, zoophilic, antrhopophilic

Front 18

Which of the three types of cutaneous mycoses are the most intense/ acute

Back 18

geophilic and zoophilic
anthropophilic are less severe perhaps due to co-evolution with humans and adaptation with the human environment

Front 19

Which of the three types of cutaneous mycoses respond better to therapy and heal spontaneously

Back 19

geophilic and zoophilic
anthropophilic are less severe perhaps due to co-evolution with humans and adaptation with the human environment

Front 20

how are the clinical syndromes caused by cutaneous mycoses classified

Back 20

anatomic location
Tinea:
capitis, barbae, manuum, coproris, curis (groin), pedi, unguium, favosa, kerion

Front 21

This a severe chronic infection of the scalp or body skin characterized by yellowish cup-shaped crusts (scutula) composed of mycelia and eithelial debris

Back 21

Tinea favosa caused by a dermatophyte (epidermophyton, microsporum, trichophyton)

Front 22

Severe inflammatory phenomenon characterized by a painful purulent mass originating from folliculitis, may occur anywhere on body but is usually in the scalp or beard

Back 22

Kerion caused by a dermatophyte (epidermophyton, microsporum, trichophyton)

Front 23

What are keratinases

Back 23

-keratin degrading enzymes
-produced by all dermatophyes
-adaptive because the allow invasion and provide nutrients
-environmental decompositin
-elicit host immune response

Front 24

T/F treatment of dermatophytes is relatively easy

Back 24

False
-longer tx is needed because the tissue grows slowly

Front 25

Which drugs are used to treat dermatophyte infections

Back 25

-terbinafine
-griseofulvin
-azoles