Skin and Soft Tissue Infection

Question 1

Risk factors for an SSTI

Answer 1

-History of SSTI
-Peripheral artery disease
-CKD
-Diabetes
-IV drug use

Question 2

SSTI associated complications

Answer 2

-Ulcers
-Bacteremia
-Endocarditis
-Osteomyelitis
-Sepsis

Question 3

Types of SSTIs

Answer 3

-Non-purulent
-Purulent
-Necrotizing fasciitis

Question 4

What does non-purulent SSTI look like

Answer 4

-No pus
-Tender
-Erythema
-Swelling
-Warm to touch
-Orange peel like skin

Question 5

When would you take skin cultures in non-purulent SSTI?

Answer 5

-If immunocompromised
-Severe infection
-Animal bites

Question 6

What kind of imaging is typically done in non-purulent SSTI?

Answer 6

CT/MRI to rule out necrotizing fasciitis or presence of abscess

Question 7

What is mild non-purulent SSTI?

Answer 7

No systemic signs of infection

Question 8

What is moderate non-purulent SSTI?

Answer 8

Systemic signs of infection

Question 9

What is severe non-purulent SSTI?

Answer 9

Meets two of the four SIRS criteria

Question 10

What are the four SIRS criteria?

Answer 10

-Temp over 38C or below 36C
-HR over 90
-RR over 24
-WBC over 12k or below 4k

Question 11

What are some common causative pathogens for non-purulent SSTI?

Answer 11

-Strep spp.
-MRSA if risk factors are present

Question 12

What are risk factors for MRSA?

Answer 12

-Penetrating trauma
-Evidence of MRSA elsewhere
-Nasal colonization with MRSA
-Intravenous drug use
-SIRS/severe infection
-Failed non-MRSA antibiotic regimen

Question 13

What is the treatment for mild non-purulent SSTI?

Answer 13

(oral antibiotics)
-Penicillin VK
-Cephalosporin
-Dicloxacillin (not on the market)
-Clindamycin

Question 14

What is the treatment for moderate non-purulent SSTI?

Answer 14

(IV antibiotics)
-Penicillin
-Ceftriaxone
-Cefazolin
-Clindamycin

Question 15

What is the treatment for severe non-purulent SSTI?

Answer 15

-Emergent surgical inspection/debridement
-Vancomycin + Zosyn
-Get cultures and susceptibility

Question 16

Duration of treatment for non-purulent SSTI

Answer 16

5 days

Question 17

Characteristics of purulent SSTI

Answer 17

-Pus
-Abscesses
-Furuncles
-Carbuncles

Question 18

What is an abscess?

Answer 18

Collection of pus within the dermis and deeper skin tissues

Question 19

What is a furuncle?

Answer 19

Small abscess that forms on the hair follicle

Question 20

What is a carbuncle?

Answer 20

Infection involving several adjacent follicles

Question 21

Purulent SSTI patient presentation

Answer 21

-Tender
-Red nodules
-Erythema
-Warm to touch

Question 22

When are cultures recommended for patients with a purulent SSTI?

Answer 22

Recommended for all abscess, carbuncles and patients with systemic signs of infection regardless of severity

Question 23

What imaging is done for purulent SSTI?

Answer 23

CT/MRI to confirm presence of abscess

Question 24

What is a mild purulent SSTI?

Answer 24

No systemic signs of infection

Question 25

What is a moderate purulent SSTI?

Answer 25

Systemic signs of infection

Question 26

What is a severe purulent SSTI?

Answer 26

Meets SIRS criteria

Question 27

Common causative pathogens for purulent SSTI

Answer 27

-MRSA -MSSA -Strep spp.

Question 28

Treatment for mild purulent SSTI

Answer 28

Incision and drainage

Question 29

Treatment for moderate purulent SSTI?

Answer 29

-Incision and drainage -Get culture and susceptibility -Empiric treatment then step-down to targeted treatment

Question 30

Empiric treatment for moderate purulent SSTI?

Answer 30

-Bactrim -Doxycycline

Question 31

MRSA targeted treatment for moderate purulent SSTI?

Answer 31

-Bactrim -Doxycycline

Question 32

MSSA targeted treatment for moderate purulent SSTI?

Answer 32

-Dicloxacillin (not on market) -Cephalexin

Question 33

Treatment for severe purulent SSTI?

Answer 33

-Incision and drainage -Get culture and susceptibility -Empiric treatment then step-down to targeted treatment

Question 34

Empiric treatment for severe purulent SSTI?

Answer 34

-Vanco -Dapto -Linezolid

Question 35

MRSA targeted treatment for severe purulent SSTI?

Answer 35

-Vanco -Dapto -Linezolid

Question 36

MSSA targeted treatment for severe purulent SSTI?

Answer 36

-Nafcillin -Cefazolin -Clindamycin

Question 37

Patient presentation for necrotizing fasciitis

Answer 37

-Profound systemic toxicity -Change in color of skin to maroon/purple/black -Crepitus -Edema -Severe pain

Question 38

When are cultures recommended for necrotizing fasciitis?

Answer 38

-Blood cultures are recommended given severity of infection -Wound cultures will likely be obtained from surgery

Question 39

What imaging is done for necrotizing fasciitis?

Answer 39

CT/MRI to confirm necrotizing fasciitis (look for gas) or presence of abscess

Question 40

What pathogen is the number one cause of necrotizing fasciitis?

Answer 40

Strep spp.

Question 41

Duration of treatment for purulent SSTI

Answer 41

5 days

Question 42

What is the treatment for necrotizing fasciitis?

Answer 42

-Emergent surgical inspection and debridement -Get culture and susceptibility -Empiric antibiotics then step-down to targeted antibiotics after obtaining culture and susceptibility

Question 43

What is the empiric treatment for necrotizing fasciitis?

Answer 43

Vancomycin + Zosyn

Question 44

What is the S. pyogenes targeted treatment for necrotizing fasciitis?

Answer 44

Penicillin + clindamycin

Question 45

What is the polymicrobial treatment for necrotizing fasciitis?

Answer 45

Vancomycin + Zosyn

Question 46

Duration of treatment for necrotizing fasciitis

Answer 46

-Until further debridement is no longer necessary -Until patient has improved clinically -Until fever has been absent for 48-72 hours

Question 47

Why is clindamycin commonly used to treat SSTI?

Answer 47

It inhibits streptococcal toxin production allowing penicillin to retain its efficacy

Question 48

What is impetigo?

Answer 48

-Highly contagious superficial skin infection caused by skin abrasions -Common in children and in hot/humid weather

Question 49

Impetigo patient presentation

Answer 49

-Small, painless, fluid filled vesicles that can lead to thick golden crusts -Systemic signs of infection are rare

Question 50

Should cultures be taken for impetigo?

Answer 50

Recommended to take from pus/exudates but are not required

Question 51

How do you treat impetigo with few lesions?

Answer 51

Topical mupirocin

Question 52

How do you treat impetigo with many lesions/outbreak?

Answer 52

-Dicloxacillin or cephalexin -Strep ONLY: penicillin -Allergic to penicillin or MRSA: Doxycycline, clindamycin, or bactrim

Question 53

Patient presentation for cat bites

Answer 53

Deep, sharp puncture wounds

Question 54

Patient presentation for dog/human bites

Answer 54

Cellulitis signs and symptoms

Question 55

Should you get blood cultures in animal bites?

Answer 55

They are recommended

Question 56

Common pathogens in animal bites

Answer 56

-Pasteurella -Capnocytophaga

Question 57

Duration of treatment for impetigo with few lesions

Answer 57

5 days

Question 58

Duration of treatment for impetigo with many lesions/outbreak

Answer 58

7 days

Question 59

Drug of choice for animal/human bites

Answer 59

Augmentin

Question 60

Alternative treatment for animal/human bites

Answer 60

Second/third generation cephalosporin + anaerobic coverage

Question 61

Treatment for animal/human bites in patients with beta-lactam allergy

Answer 61

-Cipro/levofloxacin + anaerobic coverage -Moxifloxacin

Question 62

What vaccines should someone get who got a animal/human bite

Answer 62

-Tdap if due -Sometimes rabies

Question 63

How long should treatment be for an established animal/human bite infection?

Answer 63

7-14 days

Question 64

How long should preemptive treatment be for animal/human bites?

Answer 64

3-5 days

Question 65

When do you give preemptive treatment for animal/human bites?

Answer 65

-Immunocompromised -Asplenia -Moderate to severe bites -Bites on face/hand -Bites that penetrate joints