Infectious Disease: SSTI

Question 1

Cellulitis Microbiology

Answer 1

Skin flora - Group A, B, C, G Streptococci
Strep pyogenenes
Staphylococcus aureaus

Question 2

Treatment of Non-purulent Cellulitis
Mild Options are
Duration of therapy?

Answer 2

Penicillin VK 250-500mg PO q6h
Cephalexin 500mg PO q6h
Dicloxacillin 500mg PO q6h
Clindamycin 300-450mg PO q6h

x7 days (can be 5d IF NOT Staph or Strep)

Question 3

Treatment of Non-purulent Cellulitis
Moderate Options are
Duration of therapy?

Answer 3

Penicillin G 2-4million units IV q4-6h
Ceftriaxone 1g IV daily
Cefazolin 1g IV q8h
Clindamycin 600mg IV q8h

x7 days (can be 5d IF NOT Staph or Strep)

Question 4

Treatment of Non-purulent Cellulitis
Severe Options are
Duration of therapy?

Answer 4

RULE OUT NECROTIZING PROCESS
Empiric Therapy
Vancomycin 15-20mg/kg q12h
+
Cefepime 2gm q12h
+
Metronidazole 500mg IV TID

x7 days (can be 5d IF NOT Staph or Strep)

Question 5

Treatment of Purulent SSTIs
Mild Options are
Duration of therapy?

Answer 5

Incision and drainage alone
*Drainable lesions usally < 5cm diameter

Question 6

Treatment of Purulent Cellulitis
Moderate Options for Empiric Therapy are?
Duration of therapy?

Answer 6

Incision & Drainage w/ Culture and Sensitivity PLUS
TMP/SMZ 1 DS tabs PO q12h
OR
Doxycycline 100mg PO q12

Question 7

Treatment of Purulent Cellulitis
Moderate Options for Definitive Therapy MRSA are?
Duration of therapy?

Answer 7

Incision & Drainage w/ Culture and Sensitivity PLUS
TMP/SMZ 1DS tabs PO q12h

Question 8

Treatment of Purulent Cellulitis
Severe Options for Empiric Therapy are?
Duration of therapy?

Answer 8

Incision & Drainage w/ Culture and Sensitivity PLUS
Vancomycin 15-20mg/kg q12h
Linezolid 600mg IV q12h
Daptomycin 6mg/kg IV q12h
Ceftaroline 600mg IV q12

Question 9

Treatment of Purulent Cellulitis
Moderate Options for Definitive Therapy MSSA are?
Duration of therapy?

Answer 9

Incision & Drainage w/ Culture and Sensitivity PLUS
Dicloxacillin 500mg PO q6h
Cephalexin 500mg PO q6h

Question 10

Treatment of Purulent Cellulitis
Severe Options for Definitive Therapy MRSA are?
Duration of therapy?

Answer 10

Incision & Drainage w/ Culture and Sensitivity PLUS
Vancomycin 15-20mg/kg q12h
Linezolid 600mg IV q12h
Daptomycin 6mg/kg IV q12h
Ceftaroline 600mg IV q12

Question 11

Treatment of Purulent Cellulitis
Moderate Options for Definitive Therapy MSSA are?
Duration of therapy?

Answer 11

Incision & Drainage w/ Culture and Sensitivity PLUS
Nafcillin 2g IV q4h
Cefazolin 1g IV q8h
Clindamycin 600mg IV q8h

Question 12

Bite Wounds from Animals
Microbiology

Answer 12

Pasturella multocida
S. Aureus
anaerobes
polymicrobial

Question 13

Bite Wounds from Animals
Treatment Options are

Answer 13

Amox/Clav
Cefuroxime +/- Metronidazole OR Clinda
Doxycycline
Pen VK + Dicloxacillin
FQ +/- Metronidazole OR Clinda
Bactrim +/- Metronidazole OR Clinda

Question 14

Bite Wounds from Animals
Treatment duration is?
Prophylaxis duration is?

Answer 14

5-10d
3-5d

Question 15

Bite Wounds Humans
Microbiology

Answer 15

Streptococcus spss.
S. aureus
Haemophilus spss.
Eikenella corrodens
anaerobes

Question 16

Bite Wounds Humans
Treatment Options

Answer 16

Amp/Sulbact
Amox/Clav
Ertapenem
Meropenem
Imipenem/Cliastatin
Cofoxitin

Question 17

Bite Wounds Humans
Treatment duration?
Prophylaxis duration?

Answer 17

7-14d
3-5d

Question 18

Necrotizing Fasciitis
Type I
Typically after what?
May involve what bugs?
More common in?
Skin may be spared and infection is spread

Answer 18

surgery or trauma
Bacteroides, Peptostreptococcus, Streptococci, and enterobacterales
IVDAs
slower

Question 19

Necrotizing Fasciitis
Type II
Typically caused by?
Referred to as?
_____ extending necrosis of subQ tissues and skin,gangrene severe local pain, and systemic toxicity
Early onset waht?

Answer 19

S. Pyogenes
Streptococcal gangrene (“Flesh-eating Disease”)
Rapidly
shock and organ failure

Question 20

Empiric Therapy For Type I Necrotizing Fasciitis

Answer 20

Vancomycin + [GN & anaerobic coverage]*

*Piperacillin/tazobactam
*Imipenem
*Meropenem
*Ertapenem
**D/t resistance, would avoid FQ here

Question 21

Empiric Therapy For Type II Necrotizing Fasciitis

Answer 21

Vancomycin + B-Lactam* + Clindamycin

*Penicillin G
*1st or 3rd gen cephalosporin

Question 22

Definitive Therapy for Streptococcal Necrotizing Fasciitis

Answer 22

Penicillin G 2-4million units IV q4-6hrs
+
600-900mg IV q8h

Question 23

Definitive Therapy For MSSA necrotizing fasciitis

Answer 23

Nafcillin 1-2g IV q4h OR
Oxacillin 1-2g IV q4h OR
Cefazolin 2g IV q8h

Question 24

Definitive Therapy For MRSA necrotizing fasciitis

Answer 24

Vancomycin 15mg/kg IV q12h
+
Clindamycin 600-900mg IV q8h

Question 25

Medications to consider if patient is not responsive to or cannot tolerate vancomycin for necrotizing fasciitis?

Duration?

Answer 25

Daptomycin
Ceftaroline
Linezolid

14d (could be shorter or longer depending on surgery, Clinda may only need to be on-board for 3-5d)

Question 26

Septic Arthritis
Microbiology

Answer 26

S. aureus
Streptococcus spss.
N. gonorrheae
E. coli
P. aeruginosa

Question 27

Septic Arthritis
Treatment
Duration?

Answer 27

Ceftriaxone + Vancomycin tailor as needed
2-3 weeks

Question 28

Osteomyelitis
Microbiology

Answer 28

Streptococcus spss.
S. aureus
GN
anaerobes

Question 29

SSTIs Infection Severity
Presence of >/=2 manifestations of inflammation (purulence or erythema, pain, tenderness, warmth, or induration), but area of cellulitis or erythema around an ulcer is </= 2cm and the patient has NO SIRS criteria

Answer 29

Mild

Question 30

SSTIs Infection Severity
Meets criteria for mild infection, but erythema extends > 2cm, or involves structures deeper than the skin and subQ tissue (abscesses or fasciitis) and has NO more than 1 SIRS criteria is present

Answer 30

Moderate

Question 31

SSTIs Infection Severity
Meets criteria of either Mild or Moderate Infection, but also meets SIRS criteria w/ >/= 2 of the following:
Temp > 38C or < 36C
HR > 90 bpm
RR > 20 or PaCO2 < 32 mmHg
WBC count > 12K or < 4K

Answer 31

Severe

Question 32

Abx Therapy SSTIs Mild
No Complicating features, B-lactam allergy or intolerance
Usual Pathogens?
Potential Empiric Regimens?

Answer 32

GPCocci; GPChains

Cefazolin
Cephalexin
nafcillin
TMP/SMX
clinda
FQ
doxycycline

Question 33

Abx Therapy SSTIs Mild
Recent abx exposure w/ 90d
Usual Pathogens?
Potential Empiric Regimens?

Answer 33

GPC + GNR

Amox/Clav
Amp/sulb
TMP/SMX
FQ

Question 34

Abx Therapy SSTIs Mild
High Risk for MRSA
Usual Pathogens?
Potential Empiric Regimens?

Answer 34

MRSA

TMP/SMX
Linezolid
Doxycycline

Question 35

Abx Therapy SSTIs Moderate or Severe
No Complicating features
Usual Pathogens?
Potential Empiric Regimens?

Answer 35

GPC +/- GNR

Amox/Clav
Amp/Sulb
Cefotetan
Cefoxitin

Question 36

Abx Therapy SSTIs Moderate or Severe
Recent Abx exposure w/n 90d
Usual Pathogens?
Potential Empiric Regimens?

Answer 36

GPC +/- GNR

Piperacillin/tazobactam
Ceftriaxone
ertapenem

Question 37

Abx Therapy SSTIs Moderate or Severe
Macerated ulcer or warm climate or resulting from a puncture wound
Usual Pathogens?
Potential Empiric Regimens?

Answer 37

GNR, including Pseudomonas

Piperacillin/tazobactam
cefepime
nafcillin + ciprofloxacin
imipenem
meropenem
doripenem

Question 38

Abx Therapy SSTIs Moderate or Severe
Ischemic Limb/necrosis/gas forming
Usual Pathogens?
Potential Empiric Regimens?

Answer 38

GPC +/- GNR +/- anaerobes

Piperacillin/tazobactam
ertapenem
imipenem
meropenem
doripenem
cetriaxone + metronidazole

Question 39

Abx Therapy SSTIs Moderate or Severe
MRSA risk Factors
Usual Pathogens?
Potential Empiric Regimens?

Answer 39

MRSA + GNR