Bacterial Skin Infections - Yu Flashcards
1
Q
impetigo ? who usually gets this
A
superficial skin infections- epidermis
children
2
Q
Folliculitis
A
pyogenic infection in hair follicle - dermis
3
Q
Furuncles (boils)
A
extension of folliculitis - dermis
4
Q
Carbuncles
A
infection extends to the deeper subcutaneous tissue with single inflammatory response ( chills and fever due to systemic spread)
-subcutaneous
5
Q
what are 3 categories of skin infections
A
spreading infections
abscess formation
necrotizing infections
6
Q
what are spreading infections called in the epidermis and dermal lymphatics and subcutaneous fat layer
A
epidermis: impetigo
dermal lymphatics: erysipelas
subcutaneous fat layer: cellulitis
7
Q
name three types of abscess formation
A
folliculitis
boils ( furuncles)
carbuncles
8
Q
necrotizing infections includes what 2 things
A
fasciits
gas gangrene
9
Q
macules
A
flat, non-palpable lesions
10
Q
papules
A
palpable lesions
11
Q
vescicles
A
palpable, fluid-filled lesions
12
Q
pustules
A
palpable and contain pus, most neutrophils with serous fluids within or beneath epidermis
13
Q
what are 3 epidermal inflammatory reactions
A
vesicle
pustule
bulla
14
Q
vesicle
A
fluid accumulation
15
Q
bulla
A
collection of serous fluid and have small numbers of inflammatory cells
16
Q
erysipelas occurs where in the skin
A
dermis
17
Q
what Direct entry into skin bacteria causes impetigo
A
Streptococcus pyogenes
Staph aureus
18
Q
what direct entry into skin bacteria causes erysipelas
A
Step. Pryogenes
19
Q
what direct entry into skin bacteria causes folliculits, boils ( furuncles), carbuncles
A
Staph. aureus
20
Q
what direct entry into skin bacteria causes necrotizing fasciitis
A
anaerobes
microaerophiles
-usually mixed infections
21
Q
what direct entry into skin bacteria causes myonecrosis gangrene
A
clostridium perfringens
22
Q
what organism causes enteric fever and what are the skin manifestations
A
Salmonella typhi
Salmonella paratyphi
- “rose spots” containing bacteria
23
Q
what organism causes septicemia and what are the skin manifestations
A
Pseudomonas aeruginosa
- ecthyma gangrenosum
24
Q
what organism causes Scarlet fever and what are the skin manifestations
A
Streptococcus pyogenes
- Erythematous rash ( toxin)
25
what organism causes toxic shock syndrome and what are the skin manifestations
Staphlyococcus aureus
| - rash and desquamation ( toxin)
26
what exogenous bacteria causes folliculitis
Staphylococci
| Pseudomonas species
27
what exogenous bacteria causes carbuncles, furuncles
Staphylococci
28
what exogenous bacteria causes impetigo
Streptococci
| Staphylococci
29
what exogenous bacteria causes erysipelas
streptococci
30
what exogenous bacteria causes cellulitis
streptococci
Staphylococci
haemophilus
influenza (unimmunized children)
31
what exogenous bacteria causes synergistic cellulitis
streptococci
enteric bacteria
anaerobes
32
what exogenous bacteria causes gas gangrene
clostridia
33
what exogenous bacteria causes necrotizing fasciitis
streptococci
enteric bactera
anaerobes
34
Staph aureus is what stain bacteria
gram positivve
35
what is Staph aureus resistant to
non-spore formers to adverse condition
36
is staph aureus motile
non-motile
37
does Staph aureus need oxygen for growth
facultatively anaerobic
38
Staph aureus test for catalase and coagulase
catalase: postive
coagulase: positive
39
Staph aureus can grow in what type of media
10% NaCl
40
staph aureus can cause what 4 things
abscesses
systemic diseases
food-poisoning
toxic shock syndrome
41
name 4 virulence factors for Staph aureus
staphylococcal toxins
exfoliative toxins
enterotoxins
toxic shock syndrome toxins
42
what type of bacteria is streptococcus? how does it grow on plate
gram postive
| arranged in chains
43
how does streptococcus avoid phagocytosis
capsule
M protiens
C5a
peptidase
44
is streptococcus motile
non-motile
45
does streptococcus require oxygen
facultative anaerobic
46
test for catalase streptococcus
negative
47
what are the nutritional requirement for streptococcus
blood or serum enriched media for isolation
48
what virulence factor for streptococcus lyse RBC
streptolysin O and S
49
skin abscesses, furuncles, carbuncles are all related to what
hair follicle
50
for skin abscesses, furuncles, carbuncles it is a collection of what
pus within dermis and deeper skin tissue
51
up to 50% of cases of skin abscesses, furuncles, carbuncles are caused by what
Staph aureus
52
treatment for skin abscesses, furuncles, carbuncles
warm compresses to help drainage for small furuncles
53
Impetigo (pyoderma, impetigo contagiosa) is commonly seen in
children
54
impetigo (pyoderma, impetigo contagiosa) is commonly caused by
streptococcus pyogenes
| staphylococcus aureus
55
non-bullous impetigo vesiculopustules with crusting occurs in who
children
56
non-bullous impetigo vesiculopustules with crusting occurs where
warm, humid conditions
57
non-bullous impetigo vesiculopustules with crusting risk factors
poverty, crowding, poor hygiene , underlying scabies
58
what are the most common causes of non-bullous impetigo vesiculopustules with crusting
streptococcus pyogenes
| staphylococcus aureus
59
streptococcus pyogenes
| staphylococcus aureus what does it look like
papules progress to vesicles surrounded by erythema
60
Pustular impetigo look like what
intraepidermal vesicles filled with exudate ( pus)
| crusted lesions
61
what causes pustular impetigo
Staph. aureus
| GAS
62
what causes Bullous impetigo
Staph aureus of phage group II that produces exfoliative toxin A (no cell adhesion)
63
Bullous impetigo is localized what
staphylococcal scalded skin syndrome
64
is there a Nikolsky's sign for Bullous impetigo
no
65
Cellulitis is what type of inflammation and is accompanied by what
acute
| -inflammation of draining lymph nodes
66
what bacteria causes cellulitis
GAS and staph aureus
67
what type of children get cellulitis
unimmunized children
| - infection with H. influenza type B
68
How can an average person get cellulitis
cats or dogs
| -P. multocida
69
what is necrotizing fasciitis
deep seated infection of the subcutaneous tissue leading to destruction of fascia and fat, but may spare skin
70
what does type I necrotizing fasciitis occur
after surgery
- diabetics
- peripheral vascular disease
71
what causes type I necrotizing fasciitis
aerobic and anaerobic bacteria
72
what causes type II necrotizing fasiitis
GAS
| -MRSA
73
what bacteria causes necrotizing fasciitis? How does one get this bacteria
V. vulnificus
contaminated seawater
- mariane
74
Myonecrosis: necrotizing infection of muscle caused by what
C. perfringens
| -associated with local trauma
75
what is found in the skin of myonecrosis
gas
| - fascia and deep muscle spared
76
Staphylococcal scalded skin syndrome is called what disease
Ritter's disease
77
Ritter's syndrome is what Nikolsky's sign and what clinical presentation
positive
| - large blister with clear fluid, no organism, no leukocytes
78
Toxic Shock syndrome has what skin involvement? what is it associated with
cutaneous and soft tissue
| - tampon use
79
Nikolsky sign
skin finding in which the top layers of the skin slip away from the lower layers when slightly rubbed.
80
Pseudomonas aeruginosa has what type of staining? shape?
Gram negative
| rod
81
pseudomonas has what odor
grape-like
82
what causes pseudomonas folliculitis
immersion in contaminated water, hot tubs, swimming pools
83
pseudomonas folliculitis can be a secondary infection from what
acne or depilate their legs
84
burn wounds can have what bacterial infection
Pseudomonas aeruginosa
85
Mycobacterium leprae stains how and does it need oxgyen
gram +
| obligately aerobic rod
86
how is mycobacterium leprae spread
aerosols
87
mycobacterium leprae can be grown in what
armadillo
| footpads of mice
88
where does mycobacterium leprae grow in body
skin histiocytes ( skin macrophages )
- endothelial cells
- Schwann cells of peripheral nerves
89
how does one diagnose lepromatous leprosy
acid fast stain of nasal mucosa
90
what are two forms of leprae
tuberculoid leprosy
| lepromatous leprosy
91
p. aeruginosa bacteremia in neutropenic patients clinically present how
ecthyma gangernosa
92
clinical presntation for tuberculoid leprosy
red-blotchy lesions with anesthetic areas
93
tuberculoid leprosy has what immune response
cell-mediated response - Th1
94
Lepromatous leprosy has what immune response
humoral
| Th2
95
lepromatous leprosy is analogous to what other bacteria
miliary TB
96
treatment for lepromatous leprosy
dapsone
ribiospfampin
clofazimine
- 2 years
97
treatment for tuberculoid leprosy
dapsone
rifampin
- 6 months
98
Bacillus anthracis is what type of bacteria
gram +
| spore forming
99
name 3 virulance factors for Bacillus anthracis
EF- edema factor
LF- lethal factor
PA protective antigen
100
what makes up edema toxin
edema factor and protective antigen
101
what makes up the Lethal toxin
lethal factor and protective antigen
102
what does edema factor cause
increased intracellular cAMP-impaired flow of ions and water
103
what activates the edema factor
human calmodulin
104
role of lethal factor
induces macrophage to produce high levels of cytokines that trigger shock.
105
role of protective antigen
promotes entry of EF into phagocytic cells
106
how is bacillus anthracis spread
inhalation of aerosolized spores
107
what does chest X-ray look like with Bacillus anthracies
mediastinal widening
108
where does Bacillus anthracies replication occur in the body
lung with local exotoxin release
109
what is the most common symptoms
cutaneous anthrax
110
what is the clinical presentation for anthrax
- painless papule at site of inoculation
- progress to ulcer
- necrotic eschar
- malignant pustule: round black lesion with a rim of edema
111
what should the microscopic exam reveal about B. antrhacis
from papules
- no spires
- serpentine chain of bacilli
112
culture results for B. anthracis
non-hemolytic, sticky, colonies
113
what test confirms B. anthracis
biochemical tests
114
treatment for B. anthracis
Penicillin
Ciprofloxacin
Doxycycline
60 days
115
how does one protect themselves form B. anthracis
- inactivated cell-free product as vaccine
| - live attenuated vaccine
