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Flashcards in Microbiology Deck (55):
1

What is colonization?

presence of bacteria in insufficient numbers to cause infection

2

How do normal cutaneous flora prevent infection from pathogenic organisms?

through hydrolysis of skin lipids found in sebum to free FAs, which are toxic to some bacteria

3

What causes non-bullous impetigo?

staph aureus (and staph pyogenes)

4

What causes bullous impetigo?

staph aureus phage II, type 71

5

What structural component does bullous impetigo interrupt?

desmogleins

6

How do you treat impetigo?

antibiotics

7

How do you diagnose impetigo?

clinically and with a superficial wound culture

8

Describe common features of Ecthyma.

Typically related to trauma
pustules and vesicles followed by ulcerations with thick adherent crust
Heals with scarring

9

How do you diagnose ecthyma?

wound culture

10

How do you treat ecthyma?

antibiotics

11

What causes ecthyma?

steph pyogens or staph aureus

12

What is an abscess?

a collection of pus with surrounding fibrous reaction

13

What is a furuncle?

an abscess that involves a hair follicle

14

What is a carbuncle?

A collection of furuncles

15

What may mimic an abscess?

A sterile, inflamed ruptured cyst

16

How are abscesses treated?

warm compress, incision and drainage, and possibly antibiotics

17

How do you diagnose an abscess?

clinical appearance and culture of purulent exudate

18

What causes erysipelas?

steph pyrogenes

19

what are some common features of erysipelas?

commonly affects elderly patients
Erythematous plaque with sharply demarcated border
face and lower extremities often involved
lymphatic destruction may result in recurrent infections

20

what causes Erythrasma?

corynebacterium minutissimum

21

What pathology reveals coral red fluoreseence in the wood's lamp?

Erythrasma

22

What is the treatment for erythrasma?

topical antibiotics or antifungals

23

What is the presentation of erythrasma?

well-defined erythematous patches with fine scale
involves axillae, inguinal folds, gluteal cleft and other sites of moist occlusion

24

What dermatophytes cause tinea?

trichophyton, epidermophyton, and microsporum

25

Tinea cruris spares what?

the scrotum

26

How is tinea diagnosed?

KOH revels branching hyphae (septate)

27

How is tinea treated?

topical antifungals--> clotimazole and terbinafine

28

What causes Pityriasis (tinea) versicolor?

Malassizia furfur

29

How do you diagnose Pityriasis versicolor?

KOH examination that revelas short hyphae and clusters of spores

30

How do you treat tinea versicolor?

topical antifungals, oral antifungals (sweat) and wash skin twice monthly with selenium sulfide to reduce reoccurrence risk

31

what causes cutaneous candidiasis?

candida yeast

32

How do you treat cutaneous candidiasis?

topical antifungals (clotrimazole and nystatin) and zinc oxide paste

33

Describe common features of Cutaneous candidiasis?

Often seen in skin folds
Erythematous patches with satellite papules and pustules
maceration
may have foul odor
may involve the scrotum

34

What pathology causes diaper dermatitis?

Cutaneous Candidiasis

35

What causes seborrheic Dermatitis?

pityrosporum yeast

36

What is the treatment for seborrheic dermatitis?

topical antifungals, low potency steriods, and anti seborrheic shampoos

37

What are some common features of seborrheic dermatitis>

yellow, greasy scale with or without underlying erythema
occurs on scalp, glabella, alar creases, chin, chest and inguinal folds

38

oral disease is cause by HSV1 or 2?

HSV 1

39

How is Herpes simplex infection diagnosed?

clinical presentation, PCR and Tzanck prep (multinucleated giant cells)

40

What is erythema multiforme (EM)?

recurrent, self-limited eruption of the skin and/or oral mucosa
reaction to an underlying HSV, but HSV is not present on skin
Presents with targetoid macules

41

Those with Varcella Zoster are at risk for what other pathology?

postherpetic neuralgia

42

How is varicella zoster diagnosed?

Tzanck prep

43

What is the treatment for Varicella Zoster?

antivirals and VZV vaccine

44

What part of the epidermis does HPV effect?

basal keratinocytes

45

What are the warts called that affect the genitals?

condyloma acuminata

46

What subtypes of HPV carry a risk for cervical cancer?

16, 18, 33, and 35

47

pouring what over warts may improve detection?

vinegar

48

What are treatments for warts?

salicyclic acid, cryotherapy, immunotherapy, electrodessication and curettage, laser, and vaccine

49

How do you treat Molluscum Contagiosum?

cryotherapy, curettage, immunotherapy or it resolves spontaneously

50

What causes Erythema Infectiosum (fifth disease)?

Parovirus B19

51

How is erythema infectiosum spread?

through respiratory secretions

52

Where does the sarcopetes scabei mite live?

the stratum corneum

53

how does scabies present?

itense itching, inflammatory papules, vesicles and burrows (linear tracks)

54

What is the treatment for scabies?

topical antiscabetics (permethrin 5% cream)

55

How is erythema infectiosum treated?

No effective treatment