SSTI & DFI Flashcards
How do non-purulent SSTIs present?
- tender
- erythema
- swelling
- warm to touch
- orange peel-like skin
- NO PUS
How are non-purulent SSTIs further classified?
- mild –> no systemic signs of infection
- moderate –> systemic signs like fever & chills
- severe –> meets SIRS criteria
What are the SIRS criteria?
- Temp > 38C or < 36C
- HR > 90 bpm
- RR > 24 bpm
- WBC > 12K or < 4K
Must meet two of these to be SIRS
What are the causative pathogens for non-purulent SSTIs?
- streptococcus spp
- MRSA
- group A - strep pyogenes
What are the treatment options for a mild, non-purulent SSTI?
Duration: 5 days
Oral abx
- pen VK
- cephalosporin
- dicloxacillin
- clindamycin
pick one
What are the treatment options for a moderate, non-purulent SSTI?
Duration: 5 days
IV abx
- PCN
- ceftriaxone
- cefazolin
- clindamycin
What are the treatment options for a severe, non-purulent SSTI?
Duration: 5 days
Emergent surgical inspection/debridement followed by empiric abx
- vancomycin + piperacillin/tazobactam
Narrow based on culture and sensitivity
What is an abscess?
collection of pus within the dermis and deeper skin tissues
What is a furuncle?
boil
small abscess that involves a hair follicle
What are carbuncles?
infection involving several adjacent follicles
How does a purulent SSTI present?
- tender
- red nodules
- erythema
- warm to touch
- PUS
When are cultures recommended for purulent SSTIs?
Wound cultures are recommended for all abscesses, carbuncles, and patients with systemic signs of infection regardless of severity
How are purulent SSTIs classified?
- mild –> no systemic signs of infection
- moderate –> systemic signs of infection
- severe –> SIRS
same as non-purulent
What are the causative pathogens for purulent SSTIs?
- MRSA
- MSSA
- streptococcus spp
What are the treatment options for a mild, purulent SSTI?
- incision and drainage (I & D)
What are the empiric abx used for moderate, purulent SSTI?
- TMP/SMX or
- doxycycline
Which antibiotics are used for targeted therapy for a moderate, purulent SSTI?
- If MRSA –> TMP/SMX, doxycycline
- If MSSA –> cephalexin, dicloxacillin
Which antibiotics are used for empiric therapy for a severe, purulent SSTI?
- vancomycin or
- daptomycin or
- linezolid
Which antibiotic are used for targeted therapy for a severe, purulent SSTI?
- If MRSA –> vanc or dapto or linezolid
- If MSSA –> nafcillin or cefazolin or clindamycin
What is necrotizing fasciitis characterized as?
severe, non-purulent SSTI
Medical emergency associated with high morbidity and mortality
What are the causative pathogens for necrotizing fasciitis?
streptococcus spp
vibrio vulnificus, peptostreptococcus spp., CA-MRSA, aeromonas hydrophila, clostridium perfringens
What is the treatment process for necrotizing fasciitis?
- emergency surgical inspection/debridement
- empiric abx –> vancomycin + piperacillin/tazobactam
- cultures & susceptibility
- Targeted abx
- If strep pyogenes –> pcn + clindamycin
- If polymicrobial –> vancomycin + piperacillin/tazobactam
How is duration of abx determined for necrotizing fasciitis?
- further debridement is no longer necessary
- patient has improved clinically
- fever has been absent for 48-72 hours
What is impetigo and how does it present?
- Impetigo is a highly contagious superficial skin infection caused by skin abrasions
- small, painless, fluid filled vesicles that can lead to thick golden crusts
What is the treatment option for a case of impetigo with few lesions?
- topical mupirocin for 5 days
What are the treatment options for an impetigo outbreak with many lesions?
oral abx for 7 days
- cephalexin or dicloxacillin
- if strep only –> pcn
- if allergies or MRSA –> doxycycline, clindamycin, or TMP/SMX
What is the duration of therapy for abx for an established infection from an animal or human bite?
7-14 days
What is the duration of therapy for preemptively addressing an animal/human bite?
has been bit, but not necessarily infected
3-5 days
What is the DOC for animal/human bites?
Amox/clav
- 7-14 days for established infections
- 3-5 days for preemptive tx
What alternative agents can be used for animal/human bites?
- 2nd or 3rd gen cephalosporins + anaerobic coverage
- If B-lactam allergy –> cipro/levo + anaerobic coverage OR moxifloxacin alone
Vaccines –> Tdap if due +/- rabies
What are common causative pathogens for an infected ulcer?
- staph aureus
- group streptococci
What are MRSA risk factors for a patient with a DFI?
- previous MRSA infection w/in the past year
- local MRSA prevalence >30-50%
- recent hospitalization
- failed non-MRSA antibiotics
Exam Q: add on MRSA coverage for DFI if patient is in Indianapolis
What are the risk factors for pseudomonas for patients with a DFI?
- history of pseudomonas infection
- soaking feet in tap water
- warm climate
- severe infection
- failed non-pseudomonal antibiotics
What are the components to managing a DFI?
- surgical intervention
- glycemic control
- antibiotics
What does an antibiotic regimen for a mild DFI need to cover?
- MSSA
- group strep
What are the treatment options for a mild DFI?
needs to cover MSSA and group strep
- dicloxacillin or
- cephalexin or
- clindamycin
duration of 1-2 weeks
What drug should you switch to if a patient with a mild DFI has a history of recent abx use?
- amox/clav or
- levofloxacin or
- moxifloxacin
duration of 1-2 weeks
What are the treatment options for a mild DFI in a patient with MRSA risk factors?
- previous MRSA infection w/in past year
- local MRSA prevalence >30-50%
- recent hospitalization
- failed non-MRSA abx
- TMP/SMX or
- doxycycline
Which organisms does an abx regimen for a moderate DFI need to cover?
- MSSA
- group strep
- enterobacterales
- anaerobes
What are the treatment options for a moderate DFI?
- moxifloxacin
- amox/clav
- ciprofloxacin + clindamycin
- levofloxacin + clindamycin
duration 2-3 weeks
What drugs should be used for a moderate DFI in a patient with pseudomonal risk factors?
- ciprofloxacin + clindamycin
- levofloxacin + clindamycin
- could maybe switch clinda for metronidazole if using levofloxacin
Which drugs should be added onto the treatment regimen if the patient has a moderate DFI with MRSA risk factors?
- linezolid
- vancomycin
maybe doxycycline or TMP/SMX
Which organisms need to be covered when treating a severe DFI?
- MSSA
- group strep
- enterbacterales
- anaerobes
- pseudomonas
What are the treatment options for a patient with a severe DFI?
- piperacillin/tazobactam
- cefepime + clindamycin
- cefepime + metronidazole
- duration of 2-3 weeks
- carbapenems reserved for only when necessary (don’t want to develop resistance)
Which drugs can be added on to a treatment regimen for severe DFI if the patient has MRSA risk factors?
- vancomycin or
- linezolid or
- daptomycin
