Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MSII Micro Unit 2 > Bacterial and Parasitic Infections of Skin > Flashcards

Bacterial and Parasitic Infections of Skin Flashcards

1
Q

what is the disease and rash caused by S. typhimurium?

A
  • Enteric fever

- rose spot rash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the disease and rash caused by N meningitides?

A
  • meningitis

- petechial rash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the disease and rash caused by t pallidum?

A
  • syphillis

- secondary stage rashes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the disease and rash caused by rickettsia?

A
  • typhus

- hemorrhagic rash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the disease and rash caused by measles virus?

A
  • measles (duh dr. shillitoe)

- macular rash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the disease and rash caused by s. aureus?

A
  • TSS

- desquamation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the disease and rash caused by b dermatidis?

A
  • blastomycosis

- papular rash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the disease and rash caused by s pyogenes?

A
  • scarlet fever

- macules, glossitis (strawberry tongue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the disease and rash caused by viridans strep?

A
  • bacterial endocarditis

- splinter hemorrhages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the classification of S. aureus?

A
  • gram +
  • catalase +
  • coagulase +
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the virulence factors for S. aureus

A 
structural:
-protein A
-capsule
-coagulase
toxins:
-DNAse
-enterotoxin- GI problems
-exfoliatoxin-skin 
-leukocidin- kills WBCs
-TSS toxin- causes TSS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

list of conditions caused by staph

A
  • impetigo-superficial
  • abscess-follicles/sweat glands
  • surgical site/wound infections-subQ or deeper
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

list of conditions caused by strep pyrogenes

A
  • impetigo-superficial
  • erysipelas- subQ
  • cellulitis-subQ or deeper
  • necrotizing fasciitis-subQ or deeper
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

reservoir and transmission of S. aureus

A
  • Nasal carriers or infected patient pass to susceptible person via direct or indirect (fomite) contact
  • nasal carriers can also “autoinnoculate” themselves in a susceptible site
  • 30% of the population are nasal carriers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

skin layers (for this lecture)

A
  • surface
  • follicles/glands
  • subQ
  • deeper
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

impetigo

A
  • surface infection
  • caused by S. aureus and S. pyogenes
  • yellow crusted skin lesions, typically near nostrils
  • can spread across face and appear on trunk and limbs
  • more common in kids
  • very contagious
  • some cases show severe bullae- from exfoliatoxin
  • diagnosis based on clinical appearance and history
  • smears from pus may show gram + cocci in clumps or chain
  • cultures show gram pos cocci that are either coag pos, B hemolytic, DNAse pos, salt resistant (s aureus) OR
  • gram pos, coag neg, beta hemolytic, bacitracin sensitive (strep pyrogenes)
17
Q

impetigo treatment

A
  • keep area clean and dry
  • mild cases-mupirocin ointment, OTC creams won’t work
  • severe cases- penicillinase resistant penicillins (nafcillin/oxacillin) or amoxicillin with penicillinase-inhibitor, or cephalosporins
  • very extensive/drug resistant cases- get sensitivity test and prescribe appropriately- cephalosporin, clindamycin
18
Q

impetigo prevention

A
  • cover lesions and discard dressings appropriately
  • isolate infected children
  • no sharing towels/ clothing
  • laundry for infected clothing
  • wash hands
  • treat carriers topically- nose with mupirocin
19
Q

infected piercings

A
  • coagulase negative staph-S. epidermidis- attaches to nylon and plastic
  • entry site can be infected by biofilms, containing lg numbers of bacteria
  • low grade pathogens form normal skin flora that stick to foreign material
  • can be decorative or medical catheters
  • diagnosis based on clinical features, lab culture shows gram pos, catalase pos, coag neg
  • trtment- remove infected piercing/device
  • prevent by changing all indwelling catheters or IVs on a regular shcedule
  • use gold or surgical steel for piercings
  • use triple antibiotic ointment on catheters in ICU and trt carriers
20
Q

scabies

A
  • sarcoptes scabei- a mite, 1/2 mm long, 8 legs
  • burrows into skin and lays eggs
  • produces linear lesions which itch severely, due to cell mediated hypersensitivity
  • transmission by personal contact or fomites
  • diagnosed by clinical findings plus observation of mites in skin scrapings
  • prevention through hygiene- change clothes regularly and DON’T SHARE TOWELS
  • trt- topical steroids for itching, permethrin/ malathion to kill mites
21
Q

skin abscesses

A
  • localized collection of pus
  • may be deep or superficial, infected or sterile
  • numerous forms:
  • furunculitis, carbuncles, stye, acne
  • usually due to S. aureus along with multiple non-pathogenic skin bacteria
  • can also get breast abscesses
22
Q

furunculitis

A
  • ingrown hair
  • superficial sweat gland or follicle infections
  • can be spread if itched
  • stye is in the eye
23
Q

carbuncle

A
  • larger multiple fused abscesses

- fused subcutaneously

24
Q

acne

A
  • mixed infection involving increased susceptibility of the skin to infection
  • small abscesses and superficial inflammation of the surface and sebaceous glands
  • due to propionobacterium acnes- anaerobic
  • treatment includes agents to reduce skin susceptibility and topical or systemic antibiotics
25
Q

diagnosis of skin abscesses

A
  • clinical appearance and history
  • smears from pus she mixed bacterial pops
  • check for sensitivity
  • gram pos cocci
  • coag pos, beta hemolytic, DNAse pos, salt resistant (staph)
26
Q

trt for abscesses

A
  • drain- have to remove all dead tissue and cover with dry dressing
  • mupirocin ointment for mild cases
  • systemic antibiotics if severe case (extensive, deep, fever)
  • nafcillin/oxacillin 1st, then cephalosporins
  • drug sensitivity testing may be needed- may be susceptible to clindamycin or methicillin, if not, use vanco or linezolid
  • some MRSA are resistant to all antibiotics
  • prevent by hygiene, remove carriers from ICU, nurseries, and ORs. trt carriers with ointment
27
Q

scalded skin syndrome

A
  • widespread exfoliation due to localized infection with S aureus
  • toxin causes separation between epidermal cells
  • usually seen in newborns
28
Q

toxic shock syndrome

A

-systemic immune reaction to super antigen TSS toxin or strep TSS toxin

29
Q

cellulitis/erysipelas

A
  • group A strep
  • infections beneath the surface of the skin that spread in a diffuse manner
  • erysipelas is superficial, cellulitis is deeper and associated with LAD, fever, and bacteremia
  • can lead to necrotizing fasciitis (which can also be caused by Clostridium perfringens and the plague)
30
Q

necrotizing fasciitis

A
  • strep A- flesh eating bacteria- protease enzyme
  • starts as a minor skin infection which becomes rapidly extensive
  • spreads through subQ fascia with widespread necrosis and gangrene of extremities
  • no predisposing factors
  • fatal in 30% of cases
  • rare
  • not contagious
31
Q

diagnosis of cellulitis/necrotizing fascitis

A
  • clinical features
  • cultures from blood/tissue often negative
  • strep etiology is assumed
32
Q

trt of cellulitis/erysipelas

A

-penicillin or cephalosporin

33
Q

trt for necrotizing fasciitis

A
  • rapid surgical intervention, including amputation of affected digits or limbs
  • culture and sensitivity testing
34
Q

surgical site infections

A
  • approximately 2.5% of surgical patients acquire infection of surgical site
  • with strep or staph
  • infections appear 5 days- 2 weeks after surgery
  • strep show signs similar to cellulitis
  • staph infections can lead to TSS
  • treatment by local excision and drainage, antibiotics won’t help
  • elimination of carriers before surgery can reduce risk
35
Q

post strep nephritis

A
  • condition analogous to rheumatic fever, but tends to follow skin infections rather than pharyngitis
  • associated with particular M protein types

MSII Micro Unit 2 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions