-
3 most common skin flora
- staphylococcus epidermidis
- staphylococcus aureus
- streptococcus spp
-
example of direct infection
diabetic foot infection
-
examples of hematogenous spread
- meningitis petechiae
- measles
- chickenpox
-
4 classifications for uncomplicated skin infections
- mostly gram positive
- superficial = impetigo
- extends into dermis and subcutaneous fat - erysipelas
- hair follicle associated
- folliculitis
- furuncles
- carbuncles
-
5 classifications of complicated skin infections
- gram positive and negative,polymicrobial
- involve deep tissue & subcutaneous fat
- need for surgical intervention
- involvement of perianal are
- presence of coexisting diseases
-
coexisting diseases that affect complicated skin infections
- DM
- immunocompromised
- obesity
-
examples of complicated skin infections
- diabetic foot infections
- decubitus ulcers
- surgical site infections
- necrotizing fasciitis
-
examples of acute skin infections
- break in intact skin
- cuts
- burns
- bites
- trauma
- surgery
-
examples of chronic skin infections
- underlying mechanism that cause infection
- diabetic foot infection
- venous stasis ulcers
- pressure sores
-
examples of local skin infections
-
examples of diffuse skin infections
- cellulitis
- necrotizing fasciitis
-
3 ways to classify skin infections
- complicated vs uncomplicated
- acuity - acute vs chronic
- area of infection - local vs diffuse
-
differentiate between staph and strep uncomplicated skin infections
- staph - local, pus producing(boils,abscess)
- strep - diffuse (erysipelas,lymphangitis,cellulitis)
-
2 bacterial causes of impetigo
- staph aureus
- strep pyogenes
-
Tx considerations of impetigo
- number of lesions
- location of lesions
- limiting spread to others
-
first line Tx for impetigo
mupirocin ointment - 1 application TID
-
oral antibiotics for impetigo and when to use
- dicloxacillin
- cephalexin
- clindamycin
- augmentin
- if many lesion or not respinding to topical therapy
-
common bacterial cause of erysipelas and Tx of choice
- S. pyogenes
- IV/PO penicillin
- nafcillin/oxacillin or cefazolin
- affects dermis of face and lower extremities
-
common organism causing furuncle and Tx
- S. aureus
- small - moist heat to promote drainage
- large - incision and drainage
- antibiotics usually unnecessary
-
S&S of cellulitis
- tachycardia
- confusion
- hypotension
- fever
- leukocytosis
-
Tx of cellulitis
- elevate affected area to promote gravity drainage of edema and inflammatory mediators
- 1st line (unless staph/strep resistance high)
- nafcillin/oxacillin
- cefazolin
- PCN allergy - clindamyacin, vanco
- duration of Tx 5-10 days
-
drug of choice IV for MSSA SSTI
nafcillin/oxacillin
-
drug of choice PO for MSSA SSTI
dicloxacillin
-
drug of choice IV for MRSA SSTI
- vanco - trough goal > 10 mcg/mL
- 15-20 mcg/mL for severs diabetic foot
-
S&S of necrotizing fasciitis
- subcutaneous tissues will feel hard
- broad erythematous tract along skin
- probing edges of wound will allow viewing down to fascia
-
common organisms causing necrotizing fasciitis
- s. pyogenes
- vibrio vulnificus
- aeromonas hydrophila
-
risk factors for polymicrobial NF
- postoperative infections
- peripheral vascular disease/DM
- decubitus ulcers
-
Tx of NF caused by
streptococcus
s. aureus
clostridium
mixed infections
- penicillin + clindamycin
- nafcillin/oxacillin
- clindamyacin
- amp-sulbactam or pip/tazo + clinda + cipro
-
most common organism in cat/dog bites and Tx
pending identification of organism what do we empirically treat with
- pasturella - augmentin
- doxycycline or cipro
-
when do most surgical site infections present and signs to watch to determine to treat
- after 48 postoperatively
- if temp < 38.5 or HR > 110 bpm = observe
- if temp >38.5 or HR > 110 bpm = usually require antibiotics
-
4 criteria for a surgical site infection where only 1 needs to be present
- purulent incisional drainage
- positive wound culture results
- pain, tenderness, swelling, erythema at site
- diagnosis by attending surgeon or physician
-
intestinal/genital tract Tx of surgical site infections : single agents
- cefoxitin
- ampicillin/sulbactam, piperacilin/tazobactam
- carbapenem's
-
intestinal/genital tract Tx combination products
- cipro,levo
- ceftriaxone, ceftazidime
- aztreonam
- aminoglycosides
-
intestinal/genital tract surgical site infection Tx for anaerobic activity
clindamycin, metronidazole
-
when treating surgical site infections of the intestinal/genital tract what organism groups are we suspecting
anaerobes and gram (-)
-
nonintestinal Tx of surgical site infections for the trunk and extremities
-
nonintestinal surgical site infection Tx of axillary or perineum
-
infected diabetic foot classification
- 2 of these
- local swelling/induration
- erythema
- local tenderness/pain
- local warmth
- purulent discharge
-
mild classification of diabetic foot
- only involves skin and SC tissue
- erythema < 2 cm around ulcer
- exclude other causes of inflammation
-
moderate classification of diabetic foot
- erythema > 2 cm or involvement of structures deeper than SC
- no SIRS
-
severe classification of diabetic foot
- local infection + SIRS
- temp > 38 or < 36
- HR > 90 bpm
- RR > 20
- WBC > 12,000 or < 4000
-
bacteria commonly responsible for diabetic foot infection
- staphylococcus spp
- s. aureus
- coagulase-negative spp
-
when would you consider MRSA for diabetic foot infection
- history of MRSA in last year
- prevalence is high (30-50%)
- severe infections
-
when would you consider P. aeruginosa for diabetic foot infections
- only if risk factors of
- warm climates
- soaking feet/ frequent water exposure
- failed nonpseudomonal agents
- severe infection
-
when would you consider ESBL pathogens for diabetic foot infections
- primarily in warm southern climates (india)
- associated w/ neuropathy, osteomyelitis, ulcer > 4 cm2. poor glycemic control, need for surgery
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