Cutaneous Mycoses

Question 1

Cutaneous mycoses affects what

Answer 1

Skin, hair and nails

KERATINIZED not living tissue

Question 2

Description of lesions of cutaneous mycoses

Answer 2

Enclosed with central clearing and raised edges

Question 3

What purpose does keratinases (comp of cutaneous mycoses ea) have?

Answer 3

Break down keratin for absorption and utlization of amino acids

Question 4

Diseases associated with cutaneous mycoses

Answer 4

Dermatophytosis (Genera: Microsporum, Tricophyton, Epidermophyton- only on nonviable skin)
Candidiasis of skin, mucous membranes and nails (Candida albicans: most isolated and most virulent in the group)
Dermatomycosis (skin manifestation of systemic fungi)

Question 5

Causes of dermatomycosis

Answer 5

Soil fungi (Scytallidium, Fusarium, Aspergillus)
Opportunistic fungi (Cryptococcus neoformans)
Systemic fungi (Histoplasma)

Question 6

Ecological groups of dermatophytes

Answer 6

Zoophilic (parasitic to animals)
anthropophilic (parasitic to man only)
geophilic (soil and dead animals)

Question 7

Common zoophilic fungi found in PIGS

Answer 7

Microsporum nanum

Question 8

Common zoophilic fungi found in cattles

Answer 8

Tricophyton verrucosum

Question 9

Common zoophilic fungi found in hamster

Answer 9

Trichophyton mentagrophytes var erinasei

Question 10

Examples of anthropophilic dermatophytes

Answer 10

- M. audonii 
− T. rubrum
− T. schoenleinii
− T. tonsurans
− T. violaceum (color violet)

Question 11

What happens when a species evolves from geophilic to zoophilic or anthropophilic

Answer 11

It loses its ability to produce asexual conidia and reproduce sexually

Question 12

What kind of infections are produced by these fungi?

Answer 12

Anthropophilic- chronic or mild

Zoo/geo- acute

Question 13

Describe the family Arthrodermatacaea

Answer 13

Keratinolytic and generally called dermatophytes

Question 14

Genus Microsporum only affects what

Answer 14

Skin and hair

Question 15

T or F: microconidia is not present in microsporum

Answer 15

False

Question 16

Macroconidia where rough walls are not parallel and one end is pointed while the other is round with comb-like pectinate hypha

Answer 16

Microsporum

Question 17

Microsporum microconidia with 4-6 cells

Answer 17

M. gypseum

Question 18

Microsporum macroconidia with 2-4 cells

Answer 18

M. nanum

Question 19

Microsporum macroconidia with 6-12 cells

Answer 19

M. canis

Question 20

T or F: Pectinate hypha is pathognomonic of microsporum

Answer 20

False

Question 21

Tricophyton species affects

Answer 21

Hair, skin and nails

Question 22

Macroconidia is characterized by parallel smooth walls and cylinder-shape with almost uniform width

Answer 22

Tricophyon

Question 23

T or F: spiral hypha are pathognomonic of Tricophyton and are only found in secondary isolates

Answer 23

False

-commonly found in primary isolates

Question 24

These are double walled conidia which are more susceptible to antimicrobials than bacterial spores

Answer 24

Chlamydoconidia

Question 25

The only pathogenic fungi in genus epidermophyton

Answer 25

E. floccosum

Question 26

T or F: microconidia is present in epidermophyton

Answer 26

False

Question 27

Its macroconidia is described as smooth-walled, clavate/finger-shaped with 2-4 cells in small clusters

Answer 27

Epidermophyton

Question 28

Chlamydoconidia is present in these genera

Answer 28

Tricophyton | Epidermophyton (abundant)

Question 29

Tinea which targets hair shaft (eyelashes, eyebrows, scalp) and caused by Tricophyton and Microsporum

Answer 29

Tinea capitis

Question 30

More serious tinea capitis which causes hair loss characterized by occurence of masses of mycelia and epithelial debris

Answer 30

Tinea favosa

Question 31

Yellow cup-shaped crusts present in tinea favosa

Answer 31

Sculutum

Question 32

Tinea favosa observed in KOH shows

Answer 32

- Bubbles and no spores | - endothrix fungi wo arthrospores

Question 33

Affects non-hairy skin showing rings with scaly centers and possible satellite lesions (due to scratching)

Answer 33

Tinea corporis

Question 34

causative agents of Tinea corporis

Answer 34

Microsporum, E. floccosum, Tricophyton

Question 35

characterized by concentric rings, also known as Tinea corporis with design caused by T. concentricum (anthropophilic and non-itchy)

Answer 35

Tinea imbricata

Question 36

tinea affecting bearded areas of faces and neck

Answer 36

Tinea barbae

Question 37

Jock itch in moist groin areas caused by E. floccosum and and T. rubrum

Answer 37

Tinea cruris

Question 38

happens when tinea spreads from groin to buttocks

Answer 38

Tinea glutealis

Question 39

also known as athlete's foot; tinea found in toe webs & soles, even in nails

Answer 39

Tinea pedis

Question 40

what is an indicative reaction of tinea pedis due to circulating fungal antigens?

Answer 40

satellite lesions even without scratching

Question 41

T or F: satellite lesions due to Tinea pedis are positive KOH and positive culture

Answer 41

False, negative KOH and culture

Question 42

Tinea found in interdigital areas and palmar surfaces

Answer 42

Tinea manuum

Question 43

T or F: infection on the back of the hand is considered as tinea manuum

Answer 43

false, corporis

Question 44

invasion of the nail plate by DERMATOPHYTES causing brittle, discolored and thickened nails

Answer 44

Tinea unguium (Onychomycosis: caused by non-dermatophytes)

Question 45

types of onychomycosis

Answer 45

superficial distal proximal candidal (inflamed nail bed and cuticle: in people whose hands are always wet)

Question 46

Methods of disinfecting fungal spores in underwear

Answer 46

``` Drying Ironing Sunlight Boiling Alcohol Hypochlorite ```

Question 47

how are cutaneous mycoses transmitted

Answer 47

pets use of communal facilities contaminated personal materials

Question 48

how are cutaneous mycoses controlled?

Answer 48

topical creams | oral treatment such as triazoles or terbinafine

Question 49

specimens for cutaneous mycoses

Answer 49

hair stub skin scrapings nails

Question 50

kind of infection involving formation of arthroconidia outside of hair shaft and destruction of hair cuticle usually caused by non-anthropophilic agent. Infected hair fluoresces a bright greenish yellow under UV light

Answer 50

ectothrix

Question 51

possible causative agents of ectothrix infx

Answer 51

M. canis M. gypseum T. equinum T. verrucosum

Question 52

kind of infection wherein arthroconidia is formed WITHIN hairshaft and hair cuticle remains intact caused by anthropophilic agent

Answer 52

ENDOTHRIX Infc hair does not fluoresce

Question 53

what is used alongside KOH in direct examination? | (wet mount is also a method of direct ex)

Answer 53

10-30% Parker Superquink blue-black ink and gentle warming

Question 54

media used to culture cutaneous mycoses

Answer 54

SDA (non-selective), SDA with chloramphenicol and cycloheximide (Mycosel or mycobiotic agar) Dermatophyte test medium

Question 55

T or F: incubation should be done in body temp

Answer 55

False, room temp atleast 2 weeks

Question 56

Grouping of trycophyton are based on

Answer 56

requirements in media

Question 57

This group involves T. verrucosum (37 > 25C), T. schoenleinii, T. concentricum, seldom produces pores or distinctive pigments and uses INOSITOL THIAMINE REACTION

Answer 57

Group 1

Question 58

This group involves T. violaceum, seldom produces microconidia (glabrous without) but yes pigment and grows slow even in thiamine

Answer 58

Group 3

Question 59

involves tonsurans (grows rapidly in thiamine and produces microconidia), mentagrophyte and rubrum.

Answer 59

Group 2

Question 60

involves megnini (agar 6: histidine) and equnium (agar 5: nicotinic acid)

Answer 60

Group 4

Question 61

pls see table for causative agents

Answer 61

tite