Bacterial Skin (lec 22) Flashcards
Routes of infection?
1) Exogenous (disrupt skin barrier)
2) Endogenous (seeded into tissue by blood/lymph)
3) Toxin Induced (made at distant site, cause pathogenesis at/near skin)
Abscess-Forming infections? (3)
Acne
Folliculitis
Furuncles/Carbuncles
Acne Vulgaris etiology?
Propionibacterium acnes
G+
Anaerobe
Non-motile
Factors contributing to Acne? (4)
1) Genetics
2) Follicular epidermal hyperproliferation from androgens
3) Excess sebum prdxn
4) P. acnes prdxn of lipase causes inflammation
Noninflamm Acne Vulgaris caused by?
Formation of Microcomedo:
partial obstruction of follicle by sebum, keratinocytes, hair
Noninflam Acne Vulg presents as? (2)
1) Closed comedones (whiteheads)
2) Open comedones (blackheads)
Inflamm Acne Vulgaris caused by?
Rupture of follicular content into dermis
Nodular is most severe
Folliculitis is?
Superficial: small papules/pustules on erythematous base, pierced by central hair
Deep: erythematous nodules
Superficial Folliculitis caused by?
S. aureus
P. aeruginosa
S aureus presents as what forms of folliculitis?
Impetigo of Bockhart (bearded area)
Sty (eyelid)
P. aeruginosa presents as what form of folliculitis?
Hot tub/wetsuit
from contaminated H2O
breakout in swimsuit areas
Furuncles are?
Boils/large folliculitis abscess
Extend thru dermis/subQ
Face/neck, thighs/butt
Carbuncles are?
Inflamm of many hair follicles
Into dermis/subQ
Neck, back, thighs
Spreading Soft Tissue infections include?
Impetigo
Cellulitis
Nonbullous Impetigo caused by?
a/w?
S. aureus
S. pyogenes (GAS)
a/w acute glomerulonephritis