Skin and Soft Tissue Infections

Question 1

What organisms are gram positive normal flora?

Answer 1

Normal flora are predominately gram positive
* Coagulase-negative staphylococci
* Corynebacteria
* Propionobacteria (now Cutibacterium)
* Streptococci

Question 2

Which organisms are gram negative normal flora?

Answer 2

Not common
* Candida
* Malassezia spp.

Question 3

What are the types of SSTIs?

Answer 3

• Acute superficial infections (impetigo, erysipelas, lymphangitis)
• Cellulitis
• Necrotizing infections (fasciitis, gangrene)
• Animal and human bites

Question 4

Which drugs have staph resistance?

Answer 4

Erythromycin and clindamycin (don’t use!!)

Question 5

What is the D-test?

Answer 5

Automated test to look for resistance; should not use if results are positive!

Question 6

What would “inducible clindamycin resistance” mean?

Answer 6

Clindamycin should not be used

Question 7

Which drugs is HA-MRSA susceptible to (can use!)

Answer 7

Vancomycin, linezolid, daptomycin

Question 8

Which drugs is CA-MRSA susceptible to (can use!)

Answer 8

Vancomycin, Bactrim, clindamycin, tetracyclines, FQs, linezolid, daptomycin

Question 9

Which oral drugs have MRSA activity?

Answer 9

Clindamycin, linezolid, tetracyclines (doxycycline and minocycline), Bactrim, and rifampin

Question 10

Which IV drugs have MRSA activity?

Answer 10

Ceftaroline, daptomycin, linezolid, quinupristin-dalfopristin, televancin, tigecycline/erava/omada, vancomycin, oritavancin/dalbavancin

Question 11

What is the dosing scheme for dalbavancin for osteomyelitis?

Answer 11

1500 mg on day one and 1500 mg on day 8!

Question 12

1500 mg of dalbavancin is equal to how much IV vancomycin?

Answer 12

14 days (very long half life!)

Question 13

What is the main limitation of dalbavancin?

Answer 13

Cost

Question 14

What are the problems with oritavancin?

Answer 14

• 3 hour infusion
• Only compatible with D5 (have to use a liter) - not great for patients with diabetes, diabetic foot infection, etc.

Question 15

What are the benefits of the new formulation of oritavancin (Kimyrsa)?

Answer 15

• Infused over an hour
• Compatible with NS (100 ccs)

Question 16

What is a negative about Kimyrsa?

Answer 16

Even more expensive than the original oritavancin

Question 17

What is the class of dalbavancin and oritavancin?

Answer 17

Long acting lipolycopeptides

Question 18

Which can cover VRE, dalbavancin or oritavancin?

Answer 18

Oritavancin

Question 19

Can dalbavancin cover gram negatives?

Answer 19

No

Question 20

Which requires a renal adjustment, dalbavancin or oritavancin?

Answer 20

Dalbavancin

Question 21

Does dalbavancin have any drug-drug interactions?

Answer 21

No

Question 22

What is a contraindication with oritavancin?

Answer 22

Use of unfractionated heparin for 48 hours after oritavancin administration (interference with aPTT)

Question 23

What are the warnings and precautions with oritavancin?

Answer 23

• Use with warfarin
• Interferes with coagulation tests (aPTT for 48 hours and PT/INR for 24 hours)

Question 24

What is the dosing for telavancin?

Answer 24

Once daily (CANNOT be a single dose!!)

Question 25

What are some adverse effects of telavancin?

Answer 25

* Increased serum creatinine (kidney damage!) * Prolong QT interval * Foamy urine

Question 26

Is televancin used?

Answer 26

No, essentially dead.

Question 27

What are your choices for MRSA HAP/VAP?

Answer 27

1. Vancomycin 2. Linezolid 3. Ceftaroline 4. Tigacycline 5. Televancin

Question 28

What forms is tedizolid available in?

Answer 28

IV and PO

Question 29

What are some problems with linezolid?

Answer 29

* Drug-drug interactions * Bone marrow suppression/thrombocytopenia

Question 30

Are linezolid and tedizolid bacteriocidal or bacteriostatic against MRSA?

Answer 30

Bacteriostatic

Question 31

What pathogen is typically associated with injection drug use?

Answer 31

S. aureus! Can also see E. corrodens and group A step

Question 32

What organism typically causes folliculitis?

Answer 32

S. aureus

Question 33

What organism typically causes "hot-tub folliculitis"?

Answer 33

P. aeruginosa

Question 34

Are antibiotics typically needed for folliculitis?

Answer 34

No - lesions often resolve spontaneously; moist heat can facilitate drainage

Question 35

A furuncle is how many boils?

Answer 35

One

Question 36

A carbuncle is how many boils?

Answer 36

More than one

Question 37

What is the causative agent of furuncle and carbuncles?

Answer 37

S. aureus

Question 38

What is the primary therapy for furuncles and carbuncles?

Answer 38

Incisions and drainage

Question 39

Are antibiotics needed for lesions that require drainage and incision?

Answer 39

There is debate, but yes. * Bactrim for 7 days even with smaller lesions that need draining * Surrounding cellulitis or a fever, definitely use

Question 40

What is impetigo commonly caused by?

Answer 40

S. aureus and/or S. pyogenes

Question 41

What patient population is impetigo commonly seen in?

Answer 41

Children

Question 42

Is impetigo contagious?

Answer 42

Yes

Question 43

What is the main characteristic of impetigo?

Answer 43

Golden crusting, typically on the face

Question 44

What is the first line therapy for impetigo?

Answer 44

Topical mupirocin and oral agent alongside it (cephalexin, clindamycin, antistaph penicillins - assuming MSSA!)

Question 45

Which penicillins are anti-staph?

Answer 45

Cloxacillin, dicloxacillin, flucloxacillin, methicillin, and oxacillin

Question 46

What should NOT be used in impetigo?

Answer 46

OTC triple antibiotic topicals, OTC hydrocortisone

Question 47

What oral agents for impetigo will not work if MRSA?

Answer 47

Cephalexin, anti-staph penicillins

Question 48

Which oral agent for impetigo is active against both MRSA and MSSA?

Answer 48

Clindamycin

Question 49

What is lymphangitis typically caused by?

Answer 49

S. pyogenes

Question 50

What is the DOC for lymphangitis?

Answer 50

Penicillin, can use other beta lactams