SSTI Flashcards
1
Q
Boundary Membrane Concept
A
- Exists on external aspects of body
- Consists of layer(s) epithelial cells bound to each other by tight junctions, overlies a basement membrane
- Provides water tight barrier
- Separates epithelium from underlying connective tissue space
- Microbial organisms live on the barrier membrane
- Kept outside of the interstitium by the barrier membrane
- No immune response is provoked
2
Q
Barrier Violation
A
- Injury to the boundary membrane allows microbial penetration into interstitium
- Bacterial virulence can be variable, from severe to minimal
- Contamination or infection
3
Q
Uncomplicated SSTIs
A
- Superficial: cellulitis, impetiginous lesions, furnucles, simple abscesses
- Treatment usually requires antibiotics and/or simple incision and drainage
4
Q
Complicated SSTI
A
- Deep soft tissue infections: extreme pain, violaceous bullae, cutaneous hemorrhage, skin sloughing, rapid progression, gas in tissue
- May require surgical intervention: infected ulcers, infected burns, and major abscesses
- Significant underlying disease which complicates the response to treatment
- May require extensive surgical debridement and reconstruction
5
Q
Microbiology of SSTIs
A
- S. aureus ~50%
- Strept. pyogenes
- Site specific infections: indigenous organisms
- Immunocompromised + Complicated SSTIs: multiple/uncommon organisms
- Polymicrobial necrotizing fasciitis: mixed infections with anaerobes and aerobes
- Monomicrobial necrotizing fasciitis: S. pyogenes
6
Q
Abscesses + Antibiotics Indications
A
- Antibiotics not necessary for most: usually just drain and wound care
- Signs of infection: fever, elevated WBCs, left shift, septic shock
- Cellulitis or phlegmon
- Immunocompromised
- Certain foreign bodies (Marlex mesh)
7
Q
Cellulitis
A
- Spreading infection affecting epidermis and dermis
- Common pathogen: GAS, S. aureus, Group B/C/G strept
8
Q
Cellulitis Presentation
A
- Swelling
- Redness
- Edema
- Pain
- Nonelevated
- Poorly defined margins
- Lymphadenopathy
- Fever/chills: rare unless chronic, underlying disease, or immunocompromised
9
Q
SSTI General Treatment Rules
A
-Antibiotic therapy: 10-14 days
10
Q
Purulent SSTI Treatment
A
- Mild Infection: purulent SSTI, incision and drainage indicated
- Moderate: patients with purulent infection with systemic signs of infection
- Severe: failed incision/drainage plus oral antibiotics or those with severe systemic signs, immunocompromised
11
Q
Severe Systemic Signs
A
- > 38 C Fever
- Tachycardia
- Tachypnea
- Abnormal WBC
12
Q
Nonpurulent SSTI Treatment
A
- Mild Infection: typical cellulitis/erysipelas with no focus of purulence
- Moderate: typical cellulitis/erysipelas with systemic signs of infection
- Severe: failed oral antibiotic/systemic signs of infection, immunocompromised, signs of deeper infection like bullae, sloughing, hypotension, or evidence of organ dysfunction
13
Q
Erysipelas
A
- Distinct type of superficial cellulitis with extensive lymphatic involvement
- Almost always GAS
- Common in infants, young kids, elderly, and patients with nephrotic syndrome
- Manifestation: lesion with sharp, elevated border, on face/scalp/hands/genitalia, fever and leukocytosis
- Treatment: Mild/moderate non-purulent SSTI
14
Q
Impetigo
A
- Superficial cellulitis by GAS (honey crust, non-bullous) and/or S. aureus (bullous, ruptured)
- Common in children during hot/humid weather
- Spread through close contact and little to no signs of systemic infection
- Small, fluid-filled vesicles that develop into puss-filled blisters that rupture and crust, pruritus
15
Q
Impetigo Treatment
A
- Depends on number of lesions, location, and need to limit spread
- Topical: mupirocin ointment to lesions TID
- Oral: numerous lesions, location prevents topical use, or not responding to topicals
- See moderate treatment for purulent SSTI
