SSTI Flashcards
Common pathogens
Streptococcus pneumoniae
Staphylococcus aureus
Risk factors
History of SSTI
Peripheral artery disease (PAD)
Chronic kidney disease (CKD)
Diabetes mellitus (DM)
IV drug use
Complications Associated
Ulcers
Bacteremia
Endocarditis
Osteomyelitis
Sepsis
Non-purulent (cellulitis, erysipelas) characteristics
Non-purulent= no pus
Superficial infection impacting epidermis
Non-purulent (cellulitis, erysipelas) pathogens
Streptococcus spp.–> Group A
MRSA if:
- Penetrating trauma
- Evidence of MRSA elsewhere
- Nasal colonization with MRSA
- IVDU
- SIRS
- Failed non-MRSA regimen
Non-purulent (cellulitis, erysipelas) presentation
Localized and unilateral: tender, erythema, swelling, warm to touch
Orange peel skin
Non-purulent (cellulitis, erysipelas) cultures
Skin/blood cultures NOT recommended
- Due to cultures becoming contaminated with normal skin flora
Blood cultures MAY be done if immunocompromised, severe infection, animal bite
Non-purulent (cellulitis, erysipelas) imaging
CT/MRI to rule out necrotizing fasciitis or abscess
Mild non-purulent
No systemic signs
Treatment:
- Penicillin
- Cephalosporin (oral)
- Clindamycin
Moderate non-purulent
Systemic signs
Treatment:
- IV penicillin
- IV ceftriaxone
- IV cefazolin
- IV clindamycin
Severe non-purulent
SIRS Criteria
2 or more of the following:
- Temp > 38 C or < 36 C
- HR > 90
- RR > 24
- WBC > 12K or < 4K
Treatment:
- Emergency surgical inspection/debridement AND vancomycin + zosyn
Purulent characteristics
Pus
Abscess: collection of pus within the dermis and deeper skin tissue
Furuncles (boils): small abscess within the hair follicle
Carbuncles: infection involving adjacent follicles
Purulent pathogens
MRSA
MSSA
Streptococcus spp.
Purulent presentation
Tender, red nodules, erythema, warm touch
Systemic signs–>less with boils
Purulent cultures
Would culture recommended for ALL patients with abscess, carbuncle, and
patients with systemic signs of infection
Purulent imaging
CT/MRI to confirm abscess
Mild purulent
No systemic signs
Treatment: incision and drainage
Moderate purulent
Systemic signs
Treatment:
- Incision and drainage
- Bactrim or doxycycline
Targeted treatment:
- MRSA: Bactrim or doxycycline
- MSSA: Cephalexin
Severe purulent
SIRS Criteria
Empiric treatment:
- Incision and drainage + vancomycin or daptomycin or linezolid
Targeted treatment:
- MRSA: empiric
- MSSA: Nafcillin or cefazolin or clindamycin
Necrotizing Fasciitis
MEDICAL EMERGENCY
Necrotizing Fasciitis pathogens
Streptococcus spp–> Group A
CA-MRSA
Vibrio, Aeromonas peptostreptococcus, clostridium
Necrotizing Fasciitis presentation
Systemic toxicity: fever, lethargy, malaise
Change in color of skin to maroon/purple/black, crepitus, edema, pain
Necrotizing Fasciitis cultures
Blood cultures are recommended in severe infection
Wound cultures obtained from surgery
Necrotizing Fasciitis imaging
CT/MRI to confirm necrotizing fasciitis or abscess à GAS present
Necrotizing Fasciitis classification
No debridement necessary, improved clinically, lack of fever 48-72 hours
Necrotizing Fasciitis severe
Empiric treatment:
- surgical inspection/debridement + vancomycin + zosyn
Targeted treatment:
- Group A: Penicillin + clindamycin (inhibits streptococcal toxin
production to clear a path for penicillin)
- Polymicrobial: vancomycin + zosyn
Impetigo characteristics
Highly contagious superficial skin infection caused by skin abrasions
Impetigo presentation
Small, painless, fluid filled vesicles leading to thick golden crusts
Impetigo cultures
Cultures from pus are recommended
Impetigo few lesions treatment
Mupirocin topical x 5 days
Impetigo many lesions treatment
Streptococcus only: oral penicillin x 7 days
Penicillin allergy: oral doxycycline or clindamycin or Bactrim
MRSA: oral doxycycline or clindamycin or Bactrim
Cephalexin
Animal/Human bites presentation
Cat: deep, sharp puncture wound
Dog/human: cellulitis signs/symptoms
Animal/Human bite cultures
Blood cultures are recommended in animal bites
Animal/Human bite preemptive treatment
3-5 days
Immunocompromised, asplenia, moderate/severe bites, bites on face/hand, bites that penetrates joint - DOC: Augmentin
- Alternative: 2nd/3rd generation cephalosporin + anaerobic
Allergy:
- Cipro/Levofloxacin + anaerobic coverage
- Moxifloxacin
Vaccines: TdaP +/- rabies
Animal/Human bites established treatment
7-14 days
DOC: Augmentin
- Alternative: 2nd/3rd generation cephalosporin + anaerobic
Allergy:
- Cipro/Levofloxacin + anaerobic coverage
- Moxifloxacin
Vaccines: TdaP +/- rabies
