Pathophys-Day 4 Infection

Question 1

What pathogens cause impetigo most commonly?

Answer 1

Staph aureus

Strep pyogenes

Question 2

What types of impegito are there

Answer 2

Honeycomb
Bullous

usually on face

Question 3

What is erysipelas?

Answer 3

STrep infection of superficial dermal lymphatics that shows sharply demarcated, raised borders

Question 4

What is cellulitis?

Answer 4

Infection of deeper dermis (contrast to erysipelas) and subq tissue with POORLY demarcated borders, usually streptococcal

Question 5

Erysipelas vs cellulitis

Answer 5

Erysipelas-superficial dermal lymphatics, SHARP borders

Cellulitis-POOR borders, deeper dermis

Question 6

What is an abscess?

Answer 6

Collection of pus in dermis and SubQ tissue

Question 7

Boils are also called

Answer 7

furuncle

Question 8

How is a furuncle different than folliculitis?

Answer 8

Deeper - infxn extends into subq tissue

Question 9

What is a carbuncle?

Answer 9

A super furuncle (multiple ones)

Question 10

Pathogenesis of staph scalded skin syndrome

Answer 10

S aureus exotoxin binds desmoglein-1 and disrupts cell-cell adhesion

Question 11

Who gets staph scalded skin syndrome?

Answer 11

Infants/kids

Also adults with renal failure (low clearance) and immunosuppressed

Question 12

Scalded SS histology?

Answer 12

Granular layer split in epidermis; dermis lacks inflammatory infiltrate

Question 13

Scalded SS presentation?

Answer 13

Diffuse generalized erythema
Mucous membranes uninvolved
Perioral/periocular crusting and radial fissuring

Question 14

What are the three subtypes of necrotizing fasciitis?

Answer 14

I: polymicrobial
II strep
III gas gangrene

Question 15

How is NF different than cellulitis?

Answer 15

Deeper plane of infection

Question 16

What is the classic characteristic sign of necrotizing fasciitis?

Answer 16

Pain out of proportion to the clinical findings - intense tenderness, erythema, warmth, swelling

Skin turns blue/purple

Question 17

What pathogen most commonly causes TSS?

Answer 17

Staph aureus, sometimes GAS

Question 18

TSS presentation

Answer 18

Sunburn-like erythema, sandpaper papules, fever

Question 19

What is a dermatophyte?

Answer 19

A superficial cutaneous infection of a fungus that digests keratin

Question 20

What are the three divisions of dermatophyte?

Answer 20

Trichophyton, microsporum, epidermophyton

Question 21

the most common dermatophyte

Answer 21

t rubrum

Question 22

What are the consequences of tinea unguium?

Answer 22

Nail bed deformation
Hyperkeratosis
discoloration

Question 23

Ringworm aka

Answer 23

tinea corpis and tinea facei

Question 24

Jock itch AKA

Answer 24

Tinea cruris

Question 25

What pathogen causes most cases of tinea capitis?

Answer 25

T tonsurans

Question 26

Superficial fungal infection histopathology?

Answer 26

- Neutrophils sometimes in stratum corneum - Fungal hyphae in stratun corneum/follicles - best seen with PAS STAIN - Stain bright red-pink

Question 27

Candidiasis populations

Answer 27

women - vulvovaginal | immunosuppressed

Question 28

Tinea versicolor epidemiology and pathogenesis

Answer 28

Tropical regions | Altered pigment patches from overgrowth of Malassezia

Question 29

The large herpesviridae includes which viruses?

Answer 29

HSV 1 and 2 VZV EBV CMV All produce latent, incurable infxn

Question 30

Which herpes viruses cause skin infection?

Answer 30

HSV 1 and 2

Question 31

Pathogenesis of herpes infections (skin)

Answer 31

Latent infection in ganglia becomes symptomatic with fever, stress, trauma, cold, sunlight, menstraution, immunosuppression

Question 32

What causes herpes labialis?

Answer 32

HSV1

Question 33

What causes herpes genitalis?

Answer 33

HSV2

Question 34

HSV initial infection presentation

Answer 34

Starts with prodrome of tingling/pain | HSV1: asymptomatic; HSV2: systemic fever/fatigue

Question 35

HSV reactivation presentation

Answer 35

HSV1: painful GROUPED VESICLES with ulceration in 4-5 days HSV2: similar but more mild

Question 36

What is herpetic whitlow?

Answer 36

Digital herpes

Question 37

What is eczema herpeticum?

Answer 37

HSV superinfection of atopic dermatitis

Question 38

Treatment options for herpes?

Answer 38

ACV, ValACV, famciclovir, foscarnet, cidofovir

Question 39

VZV spread

Answer 39

direct contact or airborne

Question 40

VZV incubation

Answer 40

11-20 days

Question 41

How does shingles appear?

Answer 41

Produces a painful prodrome, followed by a dermatomal vesicular eruption

Question 42

What is a buzzword for zoster histopathology?

Answer 42

Multinucleated keratinocytes

Question 43

Compare the two VZV vaccines

Answer 43

Varivax: good for kids Zostavax: 60+ years old

Question 44

Who gets molluscum contagiosum and what does it look like?

Answer 44

Kids smooth, dome-shaped, umbilicated papules

Question 45

Molluscum contagiosum histopath

Answer 45

intracytoplasmic inclusions within keratinocytes (Henderson– Paterson bodies)

Question 46

HPV virus characteristics

Answer 46

unenveloped dsDNA

Question 47

What are the domains of the HPV virus?

Answer 47

URR: upstream reg region Early region: early proteins Late region: late proteins

Question 48

What are some important proteins in HPV?

Answer 48

E6 - degrades p53 E7 - inactivates Rb Overexpression of E6 and E7 found in malignant tumors

Question 49

What does HPV use to gain entry?

Answer 49

L1/L2 proteins

Question 50

Where does HPV replicate?

Answer 50

Nucleus

Question 51

Where does HPV migrate?

Answer 51

Laterally and migrates up toward suprabasal cell layers, where mature virion continues; particles are shed with desquamation of cornified layer

Question 52

Which herpes causes palmoplantar warts?

Answer 52

HPV1

Question 53

Which herpes causes common warts?

Answer 53

HPV2,4

Question 54

Which herpes causes flat warts (verrucae plana)

Answer 54

HPV 3, 10

Question 55

WHich HSV causes genital warts and which are associated with cervical carcinoma?

Answer 55

HPV-6 and 11 cause 90% of genital warts, whereas uncommon variants like HPV-16, 18, 31, and 33 are associated with an increased risk of cervical cancer.

Question 56

Gardasil protects against which herpes?

Answer 56

HPV 6, 11, 16, 18

Question 57

Cervarix protects against which herpes?

Answer 57

16 and 18