4/7 Skin & Soft Tissue + Ch 6 Flashcards
Focal infections like boils are usually from what? treatment should be what?
Usually from Staph aureus.
Treatment should cover MRSA (unless you have a culture cooking)
Spreading infections (like cellulitis) are usually from what? Sensitive to what?
Usually from GAS (strep pyogenes).
Sensitive to PCN
Cat bite: what bug?
Pasturella
Human bite: what bug?
Eikenella
Cellulitis after trauma: what bug?
Group A Strep or Staphylococci
Fresh water trauma: what bug?
Aeromonas
Salt water trauma: what bug?
Vibrio vulnificus
Rose gardener: think about what bug?
Sporotrichosis
Fish tank exposure: think about what?
Nodular skin lesions in someone with aquatic exposure including fish tanks can be from “fish tank granuloma”
bug = Mycobacterium marinum (cousin of TB)
A spreading infection like cellulitis usually is the result of what kind of event?
What organism again?
A microtrauma to the skin: a caught zipper, a toenail infection, surgery.
Likely group A strep (pyogenes)
Besides PCN, what is another antibiotic that is commonly used for Group A Strep? Is this appropriate?
Cephalexin (1st, PO )is commonly used for cellulitis - but it is overkill in most cases, since it covers much more than just Group A strep.
Focal infections like boils and other abscesses: at what point do they need to be drained?
What bug are we talking about again?
if bigger than 1cm in diameter, need to be drained.
Staph aureus.
Focal infections (boils, etc): what is a primary treatment?
- Drain if larger than 1cm
- Moist heat for comfort and to aid healing
Focal infections: when we have to use abx, what should we use? what if the pt is in the hospital?
have to target MSSA as well as MRSA.
Examples (in order of desirability):
- Trimethoprim-sulfamethoxazole (TMP/SMX)
- Doxycline
- Clindamycin
- Vancomycin (hospitalized pts)
If a pt has recurrent focal infections (staph), either due to recurrent exposure, due to close contact who sheds it, or due to chronic nasal carriage, what are preventative measures we can take?
Treat episodes as independent events
In between:
Treat contacts
Reduce nasal carriage via nasal mupirocin
What is the level of tissue involvement of the following:
- Fasciitis
- Erysipelas
- Folliculitis, Furuncle, Carbuncle
- Myositis
- Cellulitis
- Impetigo
sorry Jen - i mixed it up
no worries!
Impetigo
Erysipelas
Cellulitis & Folliculitis/Furuncle/Carbuncle (hair follicle in this layer)
Fasciitis
Myositis
Necrotizing Fasciitis: what is the bug? what can accompany the infection?
Bug: GAS or staph (OR, rarely, from gram negs)
involves the fascia, spreads quickly
If from GAS or staph, can be accompanied by shock from bacterial toxins.
Necrotizing Fasciitis: what is the appropriate response? tx?
- Hospital admission
- MRI for dx
- Rapid surgical debridement
- Start with wide abx coverage, narrow down once the pathogen is identified.
- Often use clindamycin to slow the elaboration of the toxin
Impetigo: bug?
Tx for mild cases?
More severe cases?
Typically Strep
Mild: topical ointment like mupirocin
Severe: think of this as cellulitis, and use cephalexin (+ possibly TMP/SMX depending on likelihood of MRSA).
Erysipelas: bug? treatment?
Caused by GAS
commonly has systemic sx (fever)
Tx = systemic antibiotics like oral PCN
What is paronychia? tx?
usually due to staph aureus
Inflammation of the skin around a nail bed.
Tx: moist heat, possibly drainage, abx for systemic or large lesions
(MSSA -> dicloxacillin or cephalexin)
What is Folliculitis? tx?
Multiple red spots centered on hair follicles.
Usually from Staph
Topical therapy: Polymixin B or Mupirocin
Anthrax: caused by what? what is presentation?
Caused by Bacillus anthracis (gram + rod).
Painless eschar with surrounding tissue edema in someone with exposures either to animal hides or terrorists.
Common cause of secondary cellulitis?
infection of devitalized tissue: diabetic foot infections, decubitus ulcers (bedbound pts)
What is a rare but serious cause of cellulitis? what are risk factors? what are clues?
Clostridium perfringens
Risk fx: soil or stool contamination, devitalized tissue.
Clues: gas production (on exam or XR), foul odor, tissue necrosis, rapid stread, presence of Gram + rod.
Lyme Disease: bacterium? Tx?
What are possible sx of Lyme besides rash?
Bacterium = Borrelia burgdorferi (tick-borne)
Tx = doxycycline
May have Bell’s Palsy, septic monocular arthritis, meningitis, heart block.
clostridium perferingens causes what?
how is it diagnosed?
bacterial infection of muscle -> myonecosis (gas gangrene)
xray - see bubbles
foul odor
tissue necrosis
2 scenarios that might make you think of Anthrax?
How does Anthrax stain? what shape?
- Someone who works with animal hides (a tanner)
- Terrorist scenario
Anthrax = Gram neg rods
