Exam 3 - Skin/Soft Tissue Infections Flashcards
Most skin and soft tissue infections are caused by what bugs?
Beta hemolytic streptococci
or
Staphylococcus aureus
what does SSTI stand for
skin and soft tissue infections
what are the 3 main layers of skin
outer most –> inner most layers
epidermis – dermis – subcutaneous tissue
epidermis, dermis or subcutaneous tissue?
non-vascular layer composed of continuously dividing cells and the stratum corneum
epidermis
also the outermost layer
epidermis, dermis or subcutaneous tissue?
consists of connective tissue, blood vessels, lymphatics, sensory nerve endings, sweat and sebaceous glands, hair follicles and smooth muscle fibers
dermis
also layer directly beneath epidermis
epidermis, dermis or subcutaneous tissue?
layer of loose connective tissue primarily containing adipose cells
subcutaneous tissue
innermost layer
what is fascia and where is it located?
located beneath subcutaneous tissue layer – separates skin from underlying muscle
(deep fascia forms sheath that surrounds the muscle)
what is some important patient history info to gather about SSTIs?
immune status geographic locale travel history recent trauma or surgery lifestyle hobbies animal exposure/bites previous antimicrobial therapy
Impetigo symptoms?
superficial skin infecetions: maculopapular lesions with a dried, honey colored crust – usually on face around mouth
Impetigo:
Typically/most common form is Non_____ type
other is ______ type
Non-bullous type
or
Bullous
Impetigo
Non-Bullous type: usually what bug causes infection?
vs
Bullous type: usually what bug causes it?
Non-bullous – Group A strep
Bullous: MSSA
Risk factors for impetigo?
KIDS!! Hot/humid climates poor hygiene/day care settings (aka kids) crowing malnutrition diabetes
Topical treatment for impetigo
Mupirocin 2% or retapamulin 1% ointments BID x5
Oral options for Impetigo (systemic treatment)
Dicloxacillin Erythromycin (good if PCN allergy) Clindamycin (good if PCN allergy) Cephalexin Amox/Clav
Symptoms of Cellulitis?
Rapidly spreading erythema,
edema
tenderness
warmth in skin with a poorly defined border
common pathogenesis of cellulitis?
introduced to skin during trauma, lacerations, abrasions — FISSURED TOE WEBS FROM FUNGAL INFECTIONS OF FEET, cracks in dry skin
aka any cut in the skin……
What patients are at risk for cellulitis
anybody!! happens in healthy ppl because just any cut can cause this
(common in IV drug users, arterial/venous insufficiency, pts with diabetes or obesity, immunocompromised pts)
Erysipelas:
variant of ______ – caused by ____________
has ________ appearance; often involves the face
Only in _____ dermis and has clearly ________
variant of cellulitis – caused by beta hemolytic streptococci
has peau d’ orange appearance; often involves the face
Only in upper dermis and has clearly defined borders
most likely causative pathogens for cellulitis
S. Aureus (including MRSA) Streptococus Pyogenes (group A strep)
who is at hight risk for CA-MRSA with cellulitis infections
recent tattooed people inmates injection drug users Native American Populations Gat men Contact sport participants kids
Patients with skin infections due to CA-MRSA often have cellulits AND ________
abscess/pustules
why does CA-MRSA cause cellulitis AND abscesses/pustules?
CA-MRSA has genes for PVL (a virulence factor) been associated with TISSUE NECROSIS and ABSCESS FORMATION
CA-MRSA with cellulitis often susceptible to what drugs
doxycycline
Clindamycin
SMZ-TMP
Treat cellulitis like it has MRSA when?
in populations specified before like: recent tattooed people inmates injection drug users Native American Populations Gat men Contact sport participants kids
AND
if pt has an abscess!!
Cellulitis Treatment:
if no abscess or if gram stain/culture is inconclusive: empiric therapy should cover what bugs?
Group A strep AND staphylcoccus aureus
Cellulitis Treatment:
What drugs should be used for MILD infection/no MRSA suspected
dicloxacillin
cephalexin
Cellulitis Treatment:
What drugs should be used for MILD infection/MRSA suspected
SMZ-TMP
Clindamycin
Linezolid