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Flashcards in Skin- Fungus Deck (51)
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1
Q

What is tinea capitis

A

Infection of scalp eye brows, lashes Hair breaks off scalp (ectothrix) Formation of spores on hair (endothrix)

1
Q

Tinea pedis characteristics

A

Athletes foot Agents: T mentagrophytes, T. rubrum, E. floccosum

2
Q

Tinea barbae

A

Infection of beard Usually zoophilic T. verrucosum: cattle T. Mentagrophytes: mice, rodents

2
Q

Tinea unguium

A

Nail infection by dermatophyte Trichophyton rubrum T. Mentagrophytes E. Floccosum

3
Q

Only pathogenic species of epidermophyton

A

E. Floccosum

3
Q

What is the cause of ringworm in skin

A

T. Tonsurans

3
Q

Tx for sporotrichosis

A

Oral potassium iodide

4
Q

Mycobacterium Ulcerans (buruli ulcer) vs Mycobacterium marinum

A

Slow growing Not pigmented Same presentation as Mycobacterium marinum

5
Q

What kind of staining is needed for trichosporon

A

PAS

5
Q

Cause of black piedra

A

Piedraia spp

6
Q

Microsopic examination of hair

A

Collect misshapen, broken hair from scalp Treat with KOH

7
Q

Detect mycobacteria marinum

A

Acid fast Yellow pigment in light requires 28-30 degrees C

8
Q

Treatment of nail infections

A

longterm oral systemic antifungal

8
Q

Fungal infections of external otitis

A

Aspergillus species

9
Q

What other infections found with malassezia furfur

A

Venous catheters Seborrheic dermatitis Dandruff

9
Q

Endothrix ringworm of scalp

A

T tonsurans

10
Q

Characteristics of E. Floccosum spores

A

Macroconidia Smooth walled large

11
Q

Presentation of white piedra

A

Asymptomatic growth on hair shaft White nodules easily pulled off Warm moist conditions predispose

13
Q

Tinea nigra characteristics

A

Superficial skin infection (stratum corneum) Brow to black lesions on skin (palm/soles)

14
Q

How to examine fungi (general)

A

PAS stain (gives fuchsin color) Silver stain (black) non fungal will be blue green Sabouraud agar for fungi

16
Q

Microsporum characteristics

A

Attacks skin and hair, not nails

17
Q

What are hyalohyphomycosis

A

Non black mold fungal infections Infections caused by non melanized septate, filamentous,

17
Q

Chromoblastomycosis characteristics

A

Called verrucous dermatitis From soil Gives wart like nodules Painless NO spread of infection

18
Q

Phaeohyphomycosis

A

Black mold have melanin containing filamentous hyphae Cutaneous/subcutaneous leseion

19
Q

What is Eumycetoma

A

Madura foot Infection from trauma to feet, lower extremities, hands

20
Q

What is tinea cruris

A

Jock itch T. rubrum/ e. Floccosum Usually bilateral

20
Q

Mycobacterium Chelonae characteristics

A

Acid fast Difficult to treat

21
Q

Control of white piedra

A

Shaving, application of antifungal agents

23
Q

Ectothrix ringworm of scalp

A

M. Audouinii M Canis M gypseum

25
Q

Trichophyton Characteristics

A

Attacks skin, hair, nails Life long nail infections Macroconidia smooth walled pencil shaped

26
Q

Microscopic examination of superficial fungal infections of skin

A

Take scales from advancing border of lesion

27
Q

Characteristics of Mycobacterium marinum disease

A

Cuts from working around sea water causes infection Chronic non healing lesions to hands, feet

29
Q

What causes white piedra (superficial infection)

A

Trichosporon

31
Q

Characteristics of Pityriasis versicolor

A

Superficail chronic rash Fine scaling of upper trunk and shoulders

32
Q

Typical presentation of someone with sporotrichosis

A

Working in garden got pricks from thorns on rose, swelling on skin

34
Q

What do you grow Trichophyton rubrum plate

A

Potato dextrose agar (red color)

35
Q

What are sources of fungal infections

A

Anthropophilic (humans) Zoophilic (animals) Geophilic (soil)

36
Q

UV examination (wood’s light) of fungi

A

Tinea versicolor- gold

Tinea capitis by microsporum canis and microsporum audouinii- Bright green

Tinea capitis by trichophyton- no fluorescence

37
Q

What is the most common fungal agent in the USA

A

Pseudoallescheria boydii (petriellidium boydii)

38
Q

What is the presentation of eumycetoma

A

Swelling leading to abcess formation and then granulomas

40
Q

Black piedra characteristics

A

Found on shaft of hair typically those in tropics Nodules can not be pulled off

41
Q

What is tinea corporis

A

Ringworm of upper parts of covered body Most serious chronic infection due to T rubrum

42
Q

Fungal eye infections

A

Fusarium

43
Q

Epidermophyton characteristics

A

Attacks skin and nail Not hair

45
Q

Hortae Werneckii characteristics

A

Colonies smooth, oily, glistening Aged colonies- velvety Hyphae become darker with age Beach soil

46
Q

Macroconidia characteristics

A

More numerous Rough walls spiny to warty

47
Q

Tinea nigra cause

A

Hortae werneckii

48
Q

Diagnosis of pityriasis versicolor

A

Microscopy for M. furfur (spaghetti and meatballs)

49
Q

What causes pityrisasis versicolor

A

Malassezia furfur

50
Q

What causes Sporotrichosis

A

Sporothrix schenckii Found: plants, soil, wood, moss

51
Q

What predisposes people to chronic infections

A

Diabetes Old age Malignancy