Please enable JavaScript.
Coggle requires JavaScript to display documents.
Skin Bacterial Infections JUST CAUSES (Abscess formation (Acne (Acne…
Skin Bacterial Infections
JUST CAUSES
Abscess formation
Acne
Acne vulgaris
Causes:
Cutibacterium propionibacterium acnes
Noninflammatory
Microcomedo
Follicle opening
Partially obstructed by
sebum, keratinocytes, hair
Closed comedo (whitehead)
Sebum plugs follicular canal
Sebaceous gland enlarges
Open comedo (blackhead)
Content reaches surface --> follicle dilates and reacts with O2 in air
Compacted melanin, keratinocytes, oxidized lipids
Inflammatory
Papules
Pustules
Nodules
Conglobata
Acne conglobata
Folliculitis
Causes:
Staph aureus
Pseudomonas aeruginosa
Furuncles
Causes:
Staph aureus
Carbuncles
Causes:
Spreading
Impetigo
Nonbullous
Causes:
Steph aureus
GAS
Bullous
Causes:
Staph aureus
Ecthyma
Causes:
GAS
Cellulitis
Middle aged, older adults
Causes:
Beta hemolytic strep
:star:
Group A,B,C,G, F
Staph aureus
SPECIFIC clinical circumstances
Trauma
Acinetobacter baumanni
DOG bites 🐶
Capnocytophaga canimorsus
CAT bites 🐱
Pasteurella multocida
Water
Fresh
Aeromonas hydrophila
Salt
Vibrio vulnificus
Erysipelas
Young children, older adults
Causes:
GAS
:Star:
Staph aureus
Necrotizing
Necrotizing cellulitis
Causes:
Clostridium perfringens
Clostridium spp.
Necrotizing fasciitis
Type I
Causes:
Combination of
1+ facultative anaerobic streptococci
NOT GAS
1 Anaerobic species
(NORMAL flora)
Clostridium
Peptostreptococcus
Bacteroides
OR
Enterobacteriaceae
Proteus
Enterobacter
Shigella
Salmonella
Klebsiella
E. Coli
Yersinia
Serratia
Fournier's gangrene:
Affects the male or female genitalia due to breach in GI or urethral mucosa
Type II:
Monomicrobic or streptococcal gangrene
Causes:
GAS, GABHS
:Star:
Other B hemolytic streptococcus
Strep agalactiae
Strep dysgalactiae
Type III:
Monomicrobic
Causes:
Aeromonas hydrophila
(freshwater)
Vibrio vulnificus
(seawater)
Spontaneous gangrenous myositis
Causes:
Myonecrosis
Traumatic/surgical gas gangrene
Causes:
DIRECT inoculation of wound
through surgery or injury
Clostridium perfringens type A =
traumatic
Spontaneous gas gangrene
Cause:
Hematogenous spread from GI tract
due to underlying disease
Clostridium septicum =
spontaneous
Pathogenesis + virulence
Exotoxin
:star:
Theta toxin = perfringolysin
DIRECT VASCULAR injury, hemolysis
Leukocyte degeneration and PMN destruction
Poor host inflammatory response
Kappa toxin = collagenase
RAPID spread of necrosis due to break down of collagen
Alpha toxin = phospholipase C
:star:
Lecithinase --> destroy membranes
Lyse RBC, myocyte, fibroblast, platelet, leukocyte
Decrease cardiac inotropy
Triggers histamine release, platelet aggregation,
thrombus formation
Degradative enzymes:
DNASE
Hyaluronidase
Proteaase
Gas production:
make insoluble H2 gas --> gather along fascial planes + separate tissues --> damage allows access to fresh tissue
--> COLLAPSE of blood vessels
Symptoms:
ACUTE onset with severe pain
Pale --> bronze --> purple/red --> BLACK/GREEN
Edematous + tender
Bullae
(Appearance similar to necrotizing fasciitis)
Complications:
System toxicity
Tachycardia, fever
Shick
Hemorrhagic exudate with no odor to
"sweet mousy smell"
(C. perfringens) 👃🏻🐭
Pain at site
Crepitus
Cutaneous response
Toxic shock
Scalded skin syndrome