Skin and Soft Tissue Infections

Question 1

What are the presentations of impetigo?

Question 2

What are the presentations of ecthyma?

Question 3

What are the presentations of erysipelas?

Question 4

What are the presentations of cellulitis?

Question 5

What are the presentations of furuncles?

Answer 5

Infection of the hair follicles resulting in purulent lesions.

Question 6

What are the presentations of carbuncles?

Answer 6

A group of furuncles

Question 7

What are the presentations of cutaneous abscess?

Question 8

What are the presentations of purulent cellulitis?

Question 9

What are the treatment categories for SSTI?

Answer 9

1. Impetigo (mild lesions)
2. Impetigo and Ecthyma (multiple lesions)
3. Non-purulent
4. Purulent

Question 10

What bugs do we need to cover for Impetigo (mild lesions)?

Answer 10

Beta-hemolytic strep, S. pneumoniae, S. aureus (bullous)

Question 11

What bugs do we need to cover for Impetigo and Ecthyma (multiple lesions)?

Answer 11

Beta-hemolytic strep (most commonly), S. pneumoniae&raquo_space; S. aureus (bullous impetigo)

Question 12

What bugs do we need to cover for non-purulent?

Answer 12

Beta-hemolytic strep»> S. aureus

For water exposure: Aeromonas, Vibrio vulnificus, P. aeruginosa
If hv risk factors: MRSA

Question 13

What bugs do we need to cover for purulent SSTI?

Answer 13

S. aureus»>Beta-hemolytic strep

If skin abscess, involving perioral, perirectal or vulvovaginal: gram -ve, anaerobes
If hv risk factors: MRSA

Question 14

What is the pathophysiology of general SSTI?

Answer 14

Disruption of natural skin protective barrier by physical, chemical, immunological injury –> colonisation, overgrowth

Question 15

What is the pathophysiology for DFI?

Answer 15

1. Neuropathy
   Peripheral neuropathy leads to decreased sensation of pain. Motor neuropathy leads to muscle imbalance. Autonomic neuropathy increases dryness, cracks and fissures in the skin.
2. Vasculopathy
   Poor circulation of rescue agents for clearance of microorganisms
3. Immunopathy
   Impaired immune response, increased susceptibility to infections. Worsened by hyperglycemia

Ulcer formation/wounds –> bacteria colonisation, penetration, proliferation

Question 16

What are the adjunctive therapy for DFI?

Answer 16

Glycemic control.
Daily inspection of foot for wounds or ulcers.
Proper wound care, keep wounds dry. (dressing that promotes healing, controls xs exudate)
Debridement.
Offloading.

Question 17

What is the pathophysiology for pressure ulcers?

Answer 17

Decreased blood circulation to the area receiving pressure

Question 18

What are the risk factors for pressure ulcers?

Answer 18

Reduced mobility, debilitated by severe chronic conditions (MS, stroke, cancer), Reduced consciousness, Sensory and autonomic impairment, extremes of age, malnutrition

Question 19

What are the adjunctive therapy for pressure ulcers?

Answer 19

Debridement of infected or necrotic tissue.
Local wound care (normal saline, avoid harsh chemicals).
Relief pressure (turn or reposition every 2h).

Question 20

What is the criteria for mild DFI or pressure ulcers?

Answer 20

No systemic S/S of infection.
Erythema <= 2cm in diameter ard ulcer
No bone or joint involvement.

Question 21

What is the criteria for moderate DFI or pressure ulcers?

Answer 21

No systemic S/S of infection.
Erythema > 2 cm in diameter ard ulcer.
Some bone or joint involvement.

Question 22

What is the criteria for severe DFI or pressure ulcers?

Answer 22

Systemic S/S of infection.
Erythema > 2 cm in diameter ard ulcer
Bone and join involvement.

Question 23

What bugs do we need to cover for mild DFI or pressure ulcers?

Answer 23

Streptococcus spp, S. aureus

Question 24

What bugs do we need to cover for moderate DFI or pressure ulcers?

Answer 24

Streptococcus spp, S. aureus, Gram-ve, anaerobes

If hv P. aeruginosa risk factors: P. aeruginosa

Question 25

What bugs do we need to cover for severe DFI or pressure ulcers?

Answer 25

Streptococcus spp, S. aureus, Gram -ve, anaerobes, P. aeruginosa

Question 26

What is the recommended regimen for Impetigo (mild lesions)?

Answer 26

Topical mupirocin BD x5d

Question 27

What is the recommended regimen for Impetigo and Ecthyma (multiple lesions)?

Answer 27

PO Cloxacillin or cephalexin Penicillin allergy: PO clindamycin Culture directed S. pyogenes: PO Pen V or amoxicillin Culture directed S. aureus: PO cloxacillin, cephalexin Treatment duration: 5-7d

Question 28

What is the recommended regimen for mild non-purulent SSTI?

Answer 28

PO cloxacillin or cephalexin or pen V Penicillin allergy: PO clindamycin Treatment duration: 5-10d, 14d if immunocompromised

Question 29

What is the recommended regimen for moderate purulent SSTI?

Answer 29

PO cloxacillin or cephalexin Penicillin allergy: PO clindamycin If gram -ve coverage req: PO amoxicillin clavulanate Treatment duration: 5-10d, 14d if immunocompromised

Question 30

What is the recommended regimen for mild DFI or pressure ulcers?

Answer 30

PO cloxacillin or cephalexin Penicillin allergy: PO clindamycin If MRSA risk factors: clindamycin, cotrimoxazole, doxycycline Treatment duration: 1-2 weeks

Question 31

What is the recommended regimen for moderate DFI or pressure ulcers?

Answer 31

IV Amoxicillin-clavulanate IV cefazolin/ceftriaxone + metronidazole If MRSA risk factors: add vancomycin, daptomycin or linezolid

Question 32

What is the recommended regimen for severe DFI or pressure ulcers?

Answer 32

IV piperacillin-tazobactam IV cefepime + metronidazole IV meropenem IV ciprofloxacin + clindamycin If MRSA risk factors: add IV vancomycin, daptomycin or linezolid

Question 33

What is the criteria for mild non-purulent SSTI?

Answer 33

No systemic S/S of infection Mainly cover S. pyogenes

Question 34

What is the criteria for moderate non-purulent SSTI?

Answer 34

Systemic S/S of infection, mild purulence Hv to incl MSSA

Question 35

What is the criteria for severe non-purulent SSTI?

Answer 35

Systemic S/S of infection, non-response to oral therapy, immunocompromised

Question 36

What is the criteria for mild purulent SSTI?

Answer 36

No systemic S/S of infection

Question 37

What is the criteria for moderate-severe purulent SSTI?

Answer 37

Systemic S/S of infections

Question 38

What is the recommended regimen for moderate non-purulent SSTI?

Answer 38

IV cloxacillin, cefazolin Penicillin allergy: IV clindamycin If water exposure: add ciprofloxacin Treatment duration: 5-10d, 14d if immunocompromised

Question 39

What is the recommended regimen for severe non-purulent SSTI?

Answer 39

IV piperacillin tazobactam IV cefepime IV meropenem If MRSA risk factor: add vancomycin, daptomycin or linezolid Treatment duration: 5-10d, 14d if immunocompromised

Question 40

What is the recommended regimen for severe purulent SSTI?

Answer 40

IV cloxacillin or cefazolin Penicillin allergy or MRSA coverage: clindamycin or vancomycin If req gram -ve coverage: IV amoxicillin clavulanate Treatment duration: 5-10d, 14d if immunocompromised