Skin II

Question 1

most Staphylococci are ____-resistant because they secrete ____

Answer 1

most Staphylococci are penicillin-resistant because they secrete penicillinase (hydrolyze penicillin)

Question 2

multidrug resistance of MRSA is mediated by an acquired chromosomal DNA segment, ____ which encodes a new ____

Answer 2

multidrug resistance is mediated by an acquired chromosomal DNA segment, mecA which encodes a new penicillin-binding protein 2A

Question 3

list the risk factors for MRSA in the community

Answer 3

Question 4

list the risk factors for MRSA in healthcare

Answer 4

Question 5

describe CA-MRSA vs. HA-MRSA

Answer 5

Question 6

___ is an important toxin used to differentiate between CA-MRSA and HA-MRSA

Answer 6

Pantin-Valentine leucocidin (PVL)

Question 7

list the syndromes that affect the epidermis

Answer 7

• impetigo
• folliculitis

Question 8

list the syndromes that affect the dermis

Answer 8

• ecthyma
• erysipelas
• furunculosis
• carbunculosis

Question 9

list the syndromes that affect the hypodermis (sliding layer)

Answer 9

• necrotizing fasciitis

Question 10

list the syndromes that affect the muscle

Answer 10

• myonecrosis

Question 11

describe impetigo

Answer 11

• 3rd most common skin disease among children
• risk factors:
  
  • have an injury (cut, fracture, burn, scrape)
  • contagious
• isolates of CA and HA-acquired MRSA in lesions of impetigo remains low

Question 12

describe nonbullous impetigo

Answer 12

• the teichoic acid adhesions (fibronectin-binding proteins (FnBPs)) require the epithelial cell receptor component, fibronectin, for colonization
• these fibronectin receptors are unavailable on intact skin

Question 13

in nonbullous impetigo, the ____ require the epithelial cell receptor component, ____, for colonization which is normally unavailable on ____ skin

Answer 13

in nonbullous impetigo, the teichoic acid adhesions (FnBPs) require the epithelial cell receptor component, fibronectin, for colonization which is normally unavailable on intact skin

Question 14

describe bullous impetigo

Answer 14

• group II S. aureus
• cause: exfoliating toxin, a protease that degrades desmoglein-1, resulting in loss of adhesion of the superficial epidermis
• unlike nonbullous impetigo, the lesions of bullous impetigo occur on intact skin

Question 15

bullous impetigo is caused by ____

Answer 15

bullous impetigo is caused by group II S. aureus

Question 16

bullous impetigo is caused by ___ which is a protease that degrades ___ resulting in a loss of adhesion of ____

Answer 16

bullous impetigo is caused by exfoliating toxin which is a protease that degrades desmoglein-1 resulting in a loss of adhesion of the superficial epidermis

Question 17

unlike nonbullous impetigo, the lesions of bullous impetigo occur on ____

Answer 17

unlike nonbullous impetigo, the lesions of bullous impetigo occur on intact skin

Question 18

describe the treatment/prevention of impetigo

Answer 18

Question 19

describe the condition in the image

Answer 19

Question 20

describe cellulitis and erysipelas and the most common pathogens

Answer 20

Question 21

list other causes of cellulits, erysipelas

Answer 21

“don’t have to know this”

Question 22

describe the clinical presentation of erysipelas

Answer 22

Question 23

erysipelas has ___ borders and involves the upper ___ and superficial ____

Answer 23

erysipelas has well-defined borders and involves the upper dermis and superficial lymphatics

Question 24

cellulitis has ____ borders that expands ____ and is often accompanied by ____

Answer 24

cellulitis has ill-defined borders that expands rapidly and is often accompanied by lymphangitis

Question 25

erysipelas has a predilection for ___ and \_\_\_ while cellulitis is most common in ___ and \_\_\_\_

Answer 25

erysipelas has a predilection for **young children** and **the elderly** while cellulitis is most common in **middle-aged** and **elderly people**

Question 26

cellulitis and erysipelas are not ____ since \_\_\_\_

Answer 26

cellulitis and erysipelas are not **considered contagious** since **the bacteria has to enter the body through broken skin**

Question 27

folliculitis is a superficial infection of \_\_\_\_

Answer 27

folliculitis is a superficial infection of **the hair follicles**

Question 28

list the pathogens that cause folliculitis

Answer 28

* S. aureus = most common * P. aeruginosa = associated with the use of un-chlorinated hot tubs

Question 29

describe skin abscesses (furuncles and carbuncles) and the most common cause

Answer 29

* a skin abscess is an infection of the dermis and deeper layers of skin that contains purulent material * **S. aureus** is the most common cause

Question 30

when a single follicle is infected and tracks down into the dermis, it is termed a \_\_\_\_ when multiple infected hair follicles coalesce, it is a \_\_\_\_

Answer 30

when a single follicle is infected and tracks down into the dermis, it is termed a **furuncle** when multiple infected hair follicles coalesce, it is a **carbuncle**

Question 31

the greatest risk factor for furuncles and carbuncles is \_\_\_\_

Answer 31

the greatest risk factor for furuncles and carbuncles is **intravenous drug use**

Question 32

describe the clinical presentation of furuncles and carbuncles

Answer 32

Question 33

the microorganism responsible for inflammatory acne is \_\_\_\_

Answer 33

the microorganism responsible for inflammatory acne is **Propionibacterium acnes**

Question 34

the microorganism responsible for inflammatory acne, \_\_\_\_, feeds on ___ and ___ in plugged pores and follicles

Answer 34

the microorganism responsible for inflammatory acne, **Propionibacterium acnes**, feeds on **sebum** and **keratin** in plugged pores and follicles

Question 35

describe pilonidal abscesses they are usually associated with \_\_\_\_\_

Answer 35

they are usually associated with **anaerobic bacteria**

Question 36

acute paronychia is caused by \_\_\_\_ while chronic paronychia is caused by \_\_\_\_\_

Answer 36

acute paronychia is caused by **staphylococci** while chronic paronychia is caused by **fungal infection (Candida spp.)**