Specific SSTIs

Question 1

Necrotizing fasciitis

Answer 1

Deep infection involving the superficial fascia comprising all tissue between the skin and muscles

Question 2

Fournier’s Gangrene

Answer 2

Necrotizing infection of the genitalia involving the scrotum, penis, or vulva

Question 3

Necrotizing fasciitis clinical presentation

Answer 3

Starts like cellulitis but becomes progressively worse

Question 4

Objective diagnostic clues of necrotizing fasciitis

Answer 4

Severe systemic symptoms like fever, altered mental status; severe tissue destruction in 24-48 hours

Question 5

Subjective diagnostic clues of necrotizing fasciitis

Answer 5

Disproportionate pain

Question 6

Physical exam findings of necrotizing fasciitis

Answer 6

Edema, tenderness
“Wooden-hard” induration of the subcutaneous tissue
Crepitus: crackling/grinding sound under the skin
Skin necrosis
Tissue destruction in more severe cases

Question 7

Imaging clues of necrotizing fasciitis

Answer 7

Gas in soft tissues, edema along fascia via a CT scan or MRI

Question 8

Necrotizing fasciitis microbiology: monomicrobial

Answer 8

Strep. pyrogenes- group A “flesh-eating” strep is the main cause
Staph aureus is rare
Clostridium

Question 9

Necrotizing fasciitis microbiology: polymicrobial

Answer 9

Mixed aerobic/anaerobic flora

Question 10

Necrotizing fasciitis treatment

Answer 10

SURGERY! Broad-spectrum ABX are empirically started and can be de-escalated based on culture results (blood and deep tissue)

Question 11

Broad-spectrum regimens of necrotizing fasciitis

Answer 11

Vanco with any of the following combinations:

Pip/tazo**
Meropenem, imipenem, or doripenem
Cefepime PLUS metronidazole or clindamycin

Question 12

Strep-targeted regimens of necrotizing fasciitis

Answer 12

Pen G, clindamycin

Question 13

MRSA-targeted regimen of necrotizing fasciitis

Answer 13

Vanco

Question 14

MSSA-targeted regimen of necrotizing fasciitis

Answer 14

Oxacillin/nafcillin OR cefazolin

Question 15

Clostridium species-targeted regimen of necrotizing fascitiis

Answer 15

Pen G and clindamycin

Question 16

Duration of therapy for necrotizing fasciitis

Answer 16

No definitive answer, continue treatment until debridement is no longer needed, patient is clinically improved, and is afebrile for 48-72 hours

Question 17

Animal bite microbiology

Answer 17

Likely to be polymicrobial, pasturella species common

Question 18

Human bite microbiology: aerobic

Answer 18

Strep, Staph aureus, eikenella corrodens

Question 19

Human bite microbiology: anaerobic

Answer 19

fusobacterium, peptostreptococcus, prevotella

Question 20

Bite wound IV drug of choice

Answer 20

Ampicillin/sulbactam

Question 21

Bite wound PO drug of choice

Answer 21

Amoxicillin/clavulanate

Question 22

Alternatives to bite wound treatment

Answer 22

2nd or 3rd generation cephalosporin and metronidazole, levofloxacin and metronidazole

Question 23

Clinical presentation of DFI

Answer 23

Redness, warmth, swelling, tenderness, pain, purulent discharge (≥2 are needed to call a wound infected)

Question 24

DFI microbiology: aerobic gram-positive cocci

Answer 24

Staph and strep are most common

Question 25

DFI microbiology: aerobic gram-negative bacilli

Answer 25

Pseudomonas

Question 26

DFI microbiology: anaerobes are found in what severity of infections?

Answer 26

In moderate-severe infections

Question 27

DFI workup

Answer 27

DO NOT culture a clinically uninfected wound!

Question 28

Treatment for mild DFI: MSSA, strep

Answer 28

Cephalexin, amox/clav

Question 29

Treatment for mild DFI: MRSA

Answer 29

Bactrim, doxycycline

Question 30

Treatment for moderate-severe DFI: MSSA, strep, gram-negatives, anaerobes

Answer 30

Amp/sulbactam

Question 31

Treatment for moderate-severe DFI: MRSA

Answer 31

Vanco

Question 32

Treatment for moderate-severe DFI: pseudomonas

Answer 32

Pip/tazo

Question 33

Treatment for moderate-severe DFI: MRSA, pseudomonas, anaerobes

Answer 33

Vanco PLUS one of the following combos: Pip/tazo** Cefepime and metronidazole Meropenem

Question 34

Duration of therapy: mild DFI

Answer 34

1-2 weeks, may be longer if slow to respond

Question 35

Duration of therapy: moderate DFI

Answer 35

1-3 weeks

Question 36

Duration of therapy: severe DFI

Answer 36

2-4 weeks