IC14 SSTI

Question 1

What conditions predispose to SSTIs? (6)

Answer 1

diabetes, cirrhosis, HIV, neutropenia, transplant, immunosuppressive drugs

Question 2

How should cultures be taken if the wound is draining (easily colonised)?

Answer 2

Clean the surface and obtain a culture from the base of the would (deep wound)

Question 3

How to prevent SSTIs? (2)

Answer 3

1. manage predisposing RF
2. maintain integrity with good wound care (copious irrigation and remove foreign bodies)

Question 4

Which SSTI is this?
Erythematous vesicular papules or pustules

Answer 4

Impetigo

Question 5

Which SSTI is this?
Ulcerative form of impetigo

Answer 5

Ecthyma

Question 6

Which SSTI is this?
Infection of hair follicle with pus

Answer 6

Furuncles
(Carbuncles - coalescence of furuncles that extend to subcutaneous layer)

Question 7

Which SSTI is this?
Fiery red tender plaque

Answer 7

Erysipelas

Question 8

Which SSTI is this?
Infection involving subcutaneous fat, usually on the lower limbs, always unilateral (usually with fever)

Answer 8

Cellulitis

Question 9

What are the pathogens responsible for impetigo?

Answer 9

bullous - S. aureus
strep. pyogenes

Question 10

What are the pathogens responsible for ecthyma?

Answer 10

strep pyogenes

Question 11

What are the pathogens responsible for non-purulent cellulitis/erysipelas?

Answer 11

strep pyogenes
(some s. aureus, aeromonas, vibrio, pseudomonas)

Question 12

What are the pathogens responsible for furuncles, carbuncles and purulent cellulitis?

Answer 12

mainly s. aureus (pus)
some strep pyogenes

Question 13

Treatment for mild impetigo?

Answer 13

TOP Mupirocin BD x 5 days

Question 14

Treatment for moderate impetigo and ecthyma? (3)

Answer 14

PO Cephalexin 500mg QDS
PO Cloxacillin 500mg QDS
PO Clindamycin 300mg QDS (in penicillin allergy)

Question 15

Culture directed therapy for impetigo and ecthyma: S. pyogenes?

Answer 15

PO Penicillin V 500mg QDS
(P FOR PYOGENES AND PENICILLIN)

Question 16

Culture directed therapy for impetigo and ecthyma: S. aureus?

Answer 16

PO Cephalexin 500mg QDS
PO Cloxacillin 500mg QDS

Question 17

Treatment of mild non-purulent cellulitis and erysipelas? (5)

Answer 17

PO Penicillin V 500mg QDS
PO Cephalexin 500mg QDS
PO Cloxacillin 500mg QDS
PO Amoxicillin 500mg TDS
PO Clindamycin 300mg QDS (in penicillin allergy)

Question 18

Treatment of moderate non-purulent cellulitis and erysipelas?
(hint: IV) (non-purulent q severe so treat w IV) (1)

Answer 18

IV Cefazolin 1g q8h

(CELLULITIS CEFAZOLIN)

Question 19

Treatment of severe non-purulent cellulitis and erysipelas? (2)
(hint: severe cover for what?)

Answer 19

IV Piperacillin-tazobactam 4.5g q8h
IV Meropenem

Question 20

Treatment of mild furuncles, carbuncles and purulent cellulitis?

Answer 20

Warm compress with I&D

Question 21

Treatment of moderate furuncles, carbuncles and purulent cellulitis? (3)

Answer 21

PO Cephalexin 500mg QDS
PO Cloxacillin 500mg QDS
PO Clindamycin 300mg QDS (in penicillin allergy)

(CARBUNCLES A LOT OF C SO CEPHALOSPORINS AND CLINDAMYCIN]

Question 22

Treatment of moderate furuncles, carbuncles and purulent cellulitis? (4)
(hint: IV treatment, carbuncles so a lot of C)

Answer 22

IV Cloxacillin
IV Cefazolin
IV Clindamycin
IV Vancomycin

Question 23

If CA-MRSA is suspected?

Answer 23

Doxycycline 100mg BD
Co-trimoxazole 5mg/kg q8h
Clindamycin 600mg q8h

Question 24

If HA-MRSA is suspected?

Answer 24

Vancomycin 15mg/kg q12h
Daptomycin 4mg/kg q24h
Linezolid 600mg q12h

Question 25

Treatment of mild DFI or pressure ulcer? (hint: same as moderate purulent cellulitis and carbuncles) (3)

Answer 25

PO Cephalexin 500mg QDS
PO Cloxacillin 500mg QDS
PO Clindamycin 300mg QDS (in penicillin allergy)

Question 26

Treatment of moderate DFI or pressure ulcers? (hint: IV, one is a combination) (2)
(hint: severe then cover for pseudomonas,
moderate cover for what?)

Answer 26

IV Amoxicillin-clavulanate 1.2g q8h
IV Cefazolin or Ceftriaxone with IV Metronidazole

Question 27

Treatment for severe DFI or pressure ulcers (hint: cover for pseudomonas) (4)

Answer 27

V Piperacillin-tazobactam 4.5g q8h
IV Cefepime 2g q8h with IV Metronidazole 500mg q8h
IV Meropenem
IV Ceftazidime 1g q8h or IV Ciprofloxacin with IV Clindamycin 600mg q8h

Question 28

What pathogen should be covered when dealing with severe DFI or pressure ulcers?

Answer 28

Pseudomonas

Question 29

Explain the IDSA infection severity for DFIs (mild, moderate severe)

Answer 29

Mild - lesions 2cm or below, no systemic signs of infection
Moderate - lesions larger than 2cm, no systemic signs of infection
Severe - lesions larger than 2cm, with systemic signs of infection

Question 30

According to IDSA infection severity, how long should mild, moderate and severe DFI be treated for if no bone is involved?

Answer 30

Mild - 1-2 weeks
Moderate - 1-3 weeks
Severe - 2-4 weeks

Question 31

What pathogens should be covered for in mild DFI?

Answer 31

Streptococcus + S. aureus

Question 32

What pathogens should be covered for in moderate to severe DFI?

Answer 32

Streptococcus + S. aureus + GN (+ Pseudomonas) + anaerobes

Question 33

Duration of treatment for impetigo and ecthyma?

Answer 33

7 days

Question 34

Duration of treatment for furuncles, carbuncles and purulent cellulitis?

Answer 34

5-10 days

Question 35

Duration of treatment for non-purulent cellulitis and erysipelas?

Answer 35

5-10 days

Question 36

Risk factors for pressure ulcer formation? (4)

Answer 36

1. reduced mobility (eg. spinal cord injuries)
2. severe chronic disease (MS, stroke, cancer)
3. reduced consciousness (incontinence causing bed wetting and maceration)
4. malnutrition

Question 37

When should tissue cultures be taken for DFI?

Answer 37

Moderate to severe DFI
Do deep tissue culture after cleaning and before starting abx

Question 38

What is considered as an infection for DFI?

Answer 38

Purulent discharge OR
2 or more s/sx of inflammation