Skin and Soft Tissue Infections Flashcards
What organisms are gram positive normal flora?
Normal flora are predominately gram positive
* Coagulase-negative staphylococci
* Corynebacteria
* Propionobacteria (now Cutibacterium)
* Streptococci
Which organisms are gram negative normal flora?
Not common
* Candida
* Malassezia spp.
What are the types of SSTIs?
- Acute superficial infections (impetigo, erysipelas, lymphangitis)
- Cellulitis
- Necrotizing infections (fasciitis, gangrene)
- Animal and human bites
Which drugs have staph resistance?
Erythromycin and clindamycin (don’t use!!)
What is the D-test?
Automated test to look for resistance; should not use if results are positive!
What would “inducible clindamycin resistance” mean?
Clindamycin should not be used
Which drugs is HA-MRSA susceptible to (can use!)
Vancomycin, linezolid, daptomycin
Which drugs is CA-MRSA susceptible to (can use!)
Vancomycin, Bactrim, clindamycin, tetracyclines, FQs, linezolid, daptomycin
Which oral drugs have MRSA activity?
Clindamycin, linezolid, tetracyclines (doxycycline and minocycline), Bactrim, and rifampin
Which IV drugs have MRSA activity?
Ceftaroline, daptomycin, linezolid, quinupristin-dalfopristin, televancin, tigecycline/erava/omada, vancomycin, oritavancin/dalbavancin
What is the dosing scheme for dalbavancin for osteomyelitis?
1500 mg on day one and 1500 mg on day 8!
1500 mg of dalbavancin is equal to how much IV vancomycin?
14 days (very long half life!)
What is the main limitation of dalbavancin?
Cost
What are the problems with oritavancin?
- 3 hour infusion
- Only compatible with D5 (have to use a liter) - not great for patients with diabetes, diabetic foot infection, etc.
What are the benefits of the new formulation of oritavancin (Kimyrsa)?
- Infused over an hour
- Compatible with NS (100 ccs)
What is a negative about Kimyrsa?
Even more expensive than the original oritavancin
What is the class of dalbavancin and oritavancin?
Long acting lipolycopeptides
Which can cover VRE, dalbavancin or oritavancin?
Oritavancin
Can dalbavancin cover gram negatives?
No
Which requires a renal adjustment, dalbavancin or oritavancin?
Dalbavancin
Does dalbavancin have any drug-drug interactions?
No
What is a contraindication with oritavancin?
Use of unfractionated heparin for 48 hours after oritavancin administration (interference with aPTT)
What are the warnings and precautions with oritavancin?
- Use with warfarin
- Interferes with coagulation tests (aPTT for 48 hours and PT/INR for 24 hours)
What is the dosing for telavancin?
Once daily (CANNOT be a single dose!!)
What are some adverse effects of telavancin?
- Increased serum creatinine (kidney damage!)
- Prolong QT interval
- Foamy urine
Is televancin used?
No, essentially dead.
What are your choices for MRSA HAP/VAP?
- Vancomycin
- Linezolid
- Ceftaroline
- Tigacycline
- Televancin
What forms is tedizolid available in?
IV and PO
What are some problems with linezolid?
- Drug-drug interactions
- Bone marrow suppression/thrombocytopenia
Are linezolid and tedizolid bacteriocidal or bacteriostatic against MRSA?
Bacteriostatic
What pathogen is typically associated with injection drug use?
S. aureus! Can also see E. corrodens and group A step
What organism typically causes folliculitis?
S. aureus
What organism typically causes “hot-tub folliculitis”?
P. aeruginosa
Are antibiotics typically needed for folliculitis?
No - lesions often resolve spontaneously; moist heat can facilitate drainage
A furuncle is how many boils?
One
A carbuncle is how many boils?
More than one
What is the causative agent of furuncle and carbuncles?
S. aureus
What is the primary therapy for furuncles and carbuncles?
Incisions and drainage
Are antibiotics needed for lesions that require drainage and incision?
There is debate, but yes.
* Bactrim for 7 days even with smaller lesions that need draining
* Surrounding cellulitis or a fever, definitely use
What is impetigo commonly caused by?
S. aureus and/or S. pyogenes
What patient population is impetigo commonly seen in?
Children
Is impetigo contagious?
Yes
What is the main characteristic of impetigo?
Golden crusting, typically on the face
What is the first line therapy for impetigo?
Topical mupirocin and oral agent alongside it (cephalexin, clindamycin, antistaph penicillins - assuming MSSA!)
Which penicillins are anti-staph?
Cloxacillin, dicloxacillin, flucloxacillin, methicillin, and oxacillin
What should NOT be used in impetigo?
OTC triple antibiotic topicals, OTC hydrocortisone
What oral agents for impetigo will not work if MRSA?
Cephalexin, anti-staph penicillins
Which oral agent for impetigo is active against both MRSA and MSSA?
Clindamycin
What is lymphangitis typically caused by?
S. pyogenes
What is the DOC for lymphangitis?
Penicillin, can use other beta lactams
