Cutaneous Mycoses Flashcards

1
Q

Cutaneous Mycoses are caused by a fungi generally called ___? that infect only the keratinized tissues - SKIN, HAIR, and NIALS

A

Dermatophytes

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2
Q

Note:

Dermatophytes

🐈Secrete keratinase-degrades keratin.
🐈Infections extends deep
into the epidermis.
🐈Rarely invade deeper tissue

A

🐈

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3
Q

🐈 Associated with humans only.
🐈 Person -to-person transmission through contaminated
objects (comb, hat, etc.)

🐈Elicit relatively mild and chronic infections
🐈Produce few in conidia in culture

A

Anthropophilic

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3
Q

Ecology of Dermatophytes

To determine the source of infection on??

A

Anthropophilic
Zoophilic
Geophilic

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4
Q

Associated with animals.

Direct transmission to humans by close contact with animals.

Produce more acute inflammatory infections that tend to
resolve quickly

A

Zoophilic

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5
Q

🐈Usually found in soil.
🐈Transmitted to humans by direct exposure.
🐈Produce more acuteinflammatory infections that tend to resolve quickly

A

Geophilic

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6
Q

Three (3) common genera of Dermatophytes

A

Trichophyton
Miscrosporon
Epidermophyton

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7
Q

Trichophyton spp.

-affects the Hair, skin and nails

A

T. rubrum
T. tonsurans
T. mentagrophytes
T.equinum (horse)
T. verrocosum (cattle)

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8
Q

Miscrosporon spp.

  • affects the Hair and Skin
A

🩵M. gypseum (most common)
M. canis (dogs and cats)
M. gallinae (fowl)
M. nanum (pigs)

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9
Q

Epidermophyton spp?

-affects the Skin and nails

A

E. floccosum

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10
Q

Most common causative agent of Dermatomycoses

A

Candida spp

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11
Q

Dermatophytes growth req and what medium

A

Growth for 2 weeks at 250C on Sabouraud’s dextrose agar (SDA)

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12
Q

Trichophyton species.

Colonies are cottony to granular

A

T. mentagrophytes

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13
Q

Trichophyton species.

Colonies are white and cottony surface & deep RED non-diffusable pigment

A

T. rubrum

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14
Q

Flat, powdery to velvety colony; reddish brown on reverse

A

T. tonsurans

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15
Q

🩵 Makes both macroconidia and microconidia

A

T. mentagrophytes

16
Q

globose and in clusters “grapelike” or
engrape

A

Microconidia

17
Q

thin walled,
smooth and cigar-shaped.

A

Macroconidia

18
Q

🩵 Produce 4-8 celled cylindrical macroconidia

🩵 Clavate or peg-shaped macroconidia, side of hyphae

A

T. rubrum

19
Q

appears as “Birds on fence”

A

T. rubrum

20
Q

🩵Macroconidia are variable in shape

🩵Club-shaped

A

T. tonsurans

21
Q

Microsporum species spp.

✅Powdery granular colonies
✅Fusiform, moderately thick-walled conidia, rounded tips

A

Microsporum gypseum

22
Q

✅Fluffy and white colonies with the reverse side forming lemon-yellow pigment

✅Spindle shaped macroconidia with echinulate thick-walled; with tapering spiny distal end.

A

Microsporum canis

23
Q

-Flat velvety colonies, with tan to olive green tinge

-Produces only macroconidia, smooth walled, clavate 2-4 celled, and formed small clusters
Macroconidia only

A

Epidermophyton floccosum

24
Q

What mycoses?

-Non-hairy, smooth skin
-Circular (RING) patches with advancing red, vesiculated border & central scaling, pruritic

A

Tinea corporis

✅ Trichopyton rubrum
✅ Epidermophyton floccosum

25
Q

Tinea pedis AKA?

A

(Athletes foot)

✅ Trichopyton rubrum
✅ Trichopyton mentagrophytes
✅ Epidermophyton floccosum

26
Q

Tinea cruris AKA?

A

“jock itch”
- on intertriginous area; pruritic

✅ Trichopyton rubrum,
✅ Trichopyton mentagrophytes
✅ Epidermophyton floccosum

27
Q

Affected are scalp and hair characterized as:

✅ Endothrix: fungus inside hair shaft
✅ Ectothrix: fungus on surface of
hair

What is the infection called?

A

🩵Tinea capitis

caused by:
✅ Trichopyton mentagrophytes
✅ Trichopyton tonsurans
✅ Microsporum canis

28
Q
  • Nail
  • Nails thickened or crumbling distally; discolored; lusterless. Usually associated with Tinea pedis.
A

Tinea ungium

Trichopyton rubrum,
üTrichopyton mentagrophytes
üEpidermophyton floccosum

28
Q
  • Beard hair
  • Erythematous lesions
A

Tinea barbae

Trichopyton rubrum,
üTrichopyton mentagrophytes
üEpidermophyton floccosum

29
Q

Tinea ungium also known as?

A

Onychomycosis

30
Q

Diagnosis for Cutaneous Mycoses

A

Microscopic examination
✅10-20% Potassium Hydroxide ✅(KOH) ¤ Calcaflour white
✅ Wood’s Light

Culture
✅ Sabouraud’s agar slants
✅ Mold agar
✅ Incubated for 1-4 weeks at room temperature