SSTI

Question 1

Common pathogens

Answer 1

Streptococcus pneumoniae
Staphylococcus aureus

Question 2

Risk factors

Answer 2

History of SSTI
Peripheral artery disease (PAD)
Chronic kidney disease (CKD)
Diabetes mellitus (DM)
IV drug use

Question 3

Complications Associated

Answer 3

Ulcers
Bacteremia
Endocarditis
Osteomyelitis
Sepsis

Question 4

Non-purulent (cellulitis, erysipelas) characteristics

Answer 4

Non-purulent= no pus

Superficial infection impacting epidermis

Question 5

Non-purulent (cellulitis, erysipelas) pathogens

Answer 5

Streptococcus spp.–> Group A

MRSA if:
- Penetrating trauma
- Evidence of MRSA elsewhere
- Nasal colonization with MRSA
- IVDU
- SIRS
- Failed non-MRSA regimen

Question 6

Non-purulent (cellulitis, erysipelas) presentation

Answer 6

Localized and unilateral: tender, erythema, swelling, warm to touch

Orange peel skin

Question 7

Non-purulent (cellulitis, erysipelas) cultures

Answer 7

Skin/blood cultures NOT recommended
- Due to cultures becoming contaminated with normal skin flora

Blood cultures MAY be done if immunocompromised, severe infection, animal bite

Question 8

Non-purulent (cellulitis, erysipelas) imaging

Answer 8

CT/MRI to rule out necrotizing fasciitis or abscess

Question 9

Mild non-purulent

Answer 9

No systemic signs

Treatment:
- Penicillin
- Cephalosporin (oral)
- Clindamycin

Question 10

Moderate non-purulent

Answer 10

Systemic signs

Treatment:
- IV penicillin
- IV ceftriaxone
- IV cefazolin
- IV clindamycin

Question 11

Severe non-purulent

Answer 11

SIRS Criteria
2 or more of the following:
- Temp > 38 C or < 36 C
- HR > 90
- RR > 24
- WBC > 12K or < 4K

Treatment:
- Emergency surgical inspection/debridement AND vancomycin + zosyn

Question 12

Purulent characteristics

Answer 12

Pus

Abscess: collection of pus within the dermis and deeper skin tissue

Furuncles (boils): small abscess within the hair follicle

Carbuncles: infection involving adjacent follicles

Question 13

Purulent pathogens

Answer 13

MRSA
MSSA
Streptococcus spp.

Question 14

Purulent presentation

Answer 14

Tender, red nodules, erythema, warm touch

Systemic signs–>less with boils

Question 15

Purulent cultures

Answer 15

Would culture recommended for ALL patients with abscess, carbuncle, and
patients with systemic signs of infection

Question 16

Purulent imaging

Answer 16

CT/MRI to confirm abscess

Question 17

Mild purulent

Answer 17

No systemic signs

Treatment: incision and drainage

Question 18

Moderate purulent

Answer 18

Systemic signs

Treatment:
- Incision and drainage
- Bactrim or doxycycline

Targeted treatment:
- MRSA: Bactrim or doxycycline
- MSSA: Cephalexin

Question 19

Severe purulent

Answer 19

SIRS Criteria

Empiric treatment:
- Incision and drainage + vancomycin or daptomycin or linezolid

Targeted treatment:
- MRSA: empiric
- MSSA: Nafcillin or cefazolin or clindamycin

Question 20

Necrotizing Fasciitis

Answer 20

MEDICAL EMERGENCY

Question 21

Necrotizing Fasciitis pathogens

Answer 21

Streptococcus spp–> Group A
CA-MRSA
Vibrio, Aeromonas peptostreptococcus, clostridium

Question 22

Necrotizing Fasciitis presentation

Answer 22

Systemic toxicity: fever, lethargy, malaise

Change in color of skin to maroon/purple/black, crepitus, edema, pain

Question 23

Necrotizing Fasciitis cultures

Answer 23

Blood cultures are recommended in severe infection

Wound cultures obtained from surgery

Question 24

Necrotizing Fasciitis imaging

Answer 24

CT/MRI to confirm necrotizing fasciitis or abscess à GAS present

Question 25

Necrotizing Fasciitis classification

Answer 25

No debridement necessary, improved clinically, lack of fever 48-72 hours

Question 26

Necrotizing Fasciitis severe

Answer 26

Empiric treatment: - surgical inspection/debridement + vancomycin + zosyn Targeted treatment: - Group A: Penicillin + clindamycin (inhibits streptococcal toxin production to clear a path for penicillin) - Polymicrobial: vancomycin + zosyn

Question 27

Impetigo characteristics

Answer 27

Highly contagious superficial skin infection caused by skin abrasions

Question 28

Impetigo presentation

Answer 28

Small, painless, fluid filled vesicles leading to thick golden crusts

Question 29

Impetigo cultures

Answer 29

Cultures from pus are recommended

Question 30

Impetigo few lesions treatment

Answer 30

Mupirocin topical x 5 days

Question 31

Impetigo many lesions treatment

Answer 31

Streptococcus only: oral penicillin x 7 days Penicillin allergy: oral doxycycline or clindamycin or Bactrim MRSA: oral doxycycline or clindamycin or Bactrim Cephalexin

Question 32

Animal/Human bites presentation

Answer 32

Cat: deep, sharp puncture wound Dog/human: cellulitis signs/symptoms

Question 33

Animal/Human bite cultures

Answer 33

Blood cultures are recommended in animal bites

Question 34

Animal/Human bite preemptive treatment

Answer 34

3-5 days Immunocompromised, asplenia, moderate/severe bites, bites on face/hand, bites that penetrates joint - DOC: Augmentin - Alternative: 2nd/3rd generation cephalosporin + anaerobic Allergy: - Cipro/Levofloxacin + anaerobic coverage - Moxifloxacin Vaccines: TdaP +/- rabies

Question 35

Animal/Human bites established treatment

Answer 35

7-14 days DOC: Augmentin - Alternative: 2nd/3rd generation cephalosporin + anaerobic Allergy: - Cipro/Levofloxacin + anaerobic coverage - Moxifloxacin Vaccines: TdaP +/- rabies