Immunology - Week 4 - Fungi 2 Flashcards Preview

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Flashcards in Immunology - Week 4 - Fungi 2 Deck (31):
1

What is the primary response to a fungal infection?

Innate immunity - professional phagocytes (neutrophils, macrophages and dendritic cells) and the compliment system

2

What happens if the fungi escapes the innate immue system?

adaptive response through a TH1 (activate B cells to release IgG to opsonize fungi) and TH17 response (increase inflammation)

3

What are 4 types of superficial mycoses?

Malassezia furfur
Hortaea werneckii/Exophiala werneckii
Piedraia hortae
Tricosporon

4

What type of fungus are Malazzesia furfur and Hortaea werneckii/exophiala werneckii?

Skin

5

What ype of fungus are Piedaia hortae and Tricosporon?

hair

6

What is the disease caused by Malazzezia furfur?

Pityriasias (tinea) versicolor

7

What are the symptoms of Malazezia furfur?

small hypo or hyper pigmented macules - affected areas don't tan

(skin has that white splotchy look)

8

How do you diagnose Malazezia furfur?

scotch tape test - pull piece of fungi and put on slide - look for "spaghetti and meatball" like appearance

9

How do you treat Malazzezia furfur?

topical azoles or selenium sulfide shampoo
wide spread = oral azole treatment

10

What disease does Hortaea werneckii/Exophiala werneckii cause?

symptoms?

Treatment?

Tinea nigra

Symptoms: solitary irregular pigmented macule usually on PALMS OR SOLES

Treatment? topical agents: azoles and terbinafine

not contagious

11

What can Hortaea werneckii look like?

Malignant melanoma

12

What disease does Piedraia hortae cause?

symptoms?

Treatment?

disease: black piedra

Symptoms: hard dark nodules that surround the hair shaft

Treatment: haircut and regular hair washings - topical antifungal agents

13

What disease does Trichosporon cause?

disease: white piedra

symptoms: affects hair of groin and axillae - fungus surrounds hair shaft and forms white-brown swelling around hair strand

Treatment: removal of hair and topical azoles

14

What do you have to remove during a culture of trichosporon?

Cycloheximide - it inhibits is growth

15

What are three dermatophytes?

Tricophyton
Epidermophyton
Microsporum

16

Where do dermatophytes infect?

superficial keratinized tissues (skin, hair and nails)

17

What are other names for dermatophytes?

Tineas or ring worm

18

Where do the following infect?

Tinea capitis
Tinea pedis
Tinea barbae
Tinea corporis
Tinea cruris
Tinea unguium

Tinea capitis: scalp, eyebrows, eyelashes
Tinea pedis: foot (athletes foot)
Tinea barbae: beard
Tinea corporis: smooth or glaborous skin
Tinea cruris: groin (jock itch)
Tinea unguium: nails (onychomycosis)

19

What are the two types of tinea capitis?

1) endothrix - arthrocondia found inside hair shaft
2) ectotrhix - arthroconidia found outside the hair shaft

3) favic (more severe)

20

What is one theory as to why dermatophytes only live on skin?

They are unable to grow at 37 degrees C. This prevents them from going to other areas of the body

21

What type of response from the host is elicited from zoophilic (from animals) or geophilic (from soil) dermatophytes?

Strong host response - highly inflamed lesions - respond well to therapy

22

What type of response from the host is elicited from anthropophilic dermatophytes?

Mild host response - chronic infection - difficult to cure

23

What are the symptoms of Tinea pedis?

itching vesicles and pustules, cracked skin, macerated, peeling, watery discharge

24

What are the symptoms of Tinea corporis or cruris?

tiny red pimple, actively inflamed vesicul-pustular margin and healing scaly center

25

What are the symptoms of Tinea capitis?

spread peripherally with patches of hair stumps

26

What are the symptoms of Tinea unguium?

nails will appear thickened, cracking and have a yellowish brown color

27

What organism do you have to be careful of when diagnosing dermatophytes?

Coccidioides resembles dermaophytes and are serious biohazard

28

What's a wood light and how is it used?

It's a blacklight, used to diagnose dermatophytes - some fluoresce a distinct color

29

What is the treatment for dermatophytes?

non-hair or nails: topical azole or terbinafine
chronic: oral antifungal

30

What disease does Sporothrix schenckii cause?

Symptoms?

Treatement?

lymphocutaneous sporotrichosis

symptoms: nodular lesion that will eventually ulcerate - can spread through lymphatics that drain he site and more nodes will appear

treatement: itraconazole for 3-6 months

31

Where is sporothrix schenckii found?

Soil and decaying mater - warmer climates