Skin II Flashcards
most Staphylococci are ____-resistant because they secrete ____
most Staphylococci are penicillin-resistant because they secrete penicillinase (hydrolyze penicillin)
multidrug resistance of MRSA is mediated by an acquired chromosomal DNA segment, ____ which encodes a new ____
multidrug resistance is mediated by an acquired chromosomal DNA segment, mecA which encodes a new penicillin-binding protein 2A
list the risk factors for MRSA in the community
list the risk factors for MRSA in healthcare
describe CA-MRSA vs. HA-MRSA
___ is an important toxin used to differentiate between CA-MRSA and HA-MRSA
Pantin-Valentine leucocidin (PVL)
list the syndromes that affect the epidermis
- impetigo
- folliculitis
list the syndromes that affect the dermis
- ecthyma
- erysipelas
- furunculosis
- carbunculosis
list the syndromes that affect the hypodermis (sliding layer)
- necrotizing fasciitis
list the syndromes that affect the muscle
- myonecrosis
describe impetigo
- 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
describe nonbullous impetigo
- 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
in nonbullous impetigo, the ____ require the epithelial cell receptor component, ____, for colonization which is normally unavailable on ____ skin
in nonbullous impetigo, the teichoic acid adhesions (FnBPs) require the epithelial cell receptor component, fibronectin, for colonization which is normally unavailable on intact skin
describe bullous impetigo
- 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
bullous impetigo is caused by ____
bullous impetigo is caused by group II S. aureus
bullous impetigo is caused by ___ which is a protease that degrades ___ resulting in a loss of adhesion of ____
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
unlike nonbullous impetigo, the lesions of bullous impetigo occur on ____
unlike nonbullous impetigo, the lesions of bullous impetigo occur on intact skin
describe the treatment/prevention of impetigo
describe the condition in the image
describe cellulitis and erysipelas and the most common pathogens
list other causes of cellulits, erysipelas
“don’t have to know this”
describe the clinical presentation of erysipelas
erysipelas has ___ borders and involves the upper ___ and superficial ____
erysipelas has well-defined borders and involves the upper dermis and superficial lymphatics
cellulitis has ____ borders that expands ____ and is often accompanied by ____
cellulitis has ill-defined borders that expands rapidly and is often accompanied by lymphangitis
erysipelas has a predilection for ___ and ___
while
cellulitis is most common in ___ and ____
erysipelas has a predilection for young children and the elderly
while
cellulitis is most common in middle-aged and elderly people
cellulitis and erysipelas are not ____ since ____
cellulitis and erysipelas are not considered contagious since the bacteria has to enter the body through broken skin
folliculitis is a superficial infection of ____
folliculitis is a superficial infection of the hair follicles
list the pathogens that cause folliculitis
- S. aureus = most common
- P. aeruginosa = associated with the use of un-chlorinated hot tubs
describe skin abscesses (furuncles and carbuncles) and the most common cause
- 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
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 ____
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
the greatest risk factor for furuncles and carbuncles is ____
the greatest risk factor for furuncles and carbuncles is intravenous drug use
describe the clinical presentation of furuncles and carbuncles
the microorganism responsible for inflammatory acne is ____
the microorganism responsible for inflammatory acne is Propionibacterium acnes
the microorganism responsible for inflammatory acne, ____, feeds on ___ and ___ in plugged pores and follicles
the microorganism responsible for inflammatory acne, Propionibacterium acnes, feeds on sebum and keratin in plugged pores and follicles
describe pilonidal abscesses
they are usually associated with _____
they are usually associated with anaerobic bacteria
acute paronychia is caused by ____
while
chronic paronychia is caused by _____
acute paronychia is caused by staphylococci
while
chronic paronychia is caused by fungal infection (Candida spp.)
