Skin and Soft Tissue Infection Flashcards
Risk factors for an SSTI
-History of SSTI
-Peripheral artery disease
-CKD
-Diabetes
-IV drug use
SSTI associated complications
-Ulcers
-Bacteremia
-Endocarditis
-Osteomyelitis
-Sepsis
Types of SSTIs
-Non-purulent
-Purulent
-Necrotizing fasciitis
What does non-purulent SSTI look like
-No pus
-Tender
-Erythema
-Swelling
-Warm to touch
-Orange peel like skin
When would you take skin cultures in non-purulent SSTI?
-If immunocompromised
-Severe infection
-Animal bites
What kind of imaging is typically done in non-purulent SSTI?
CT/MRI to rule out necrotizing fasciitis or presence of abscess
What is mild non-purulent SSTI?
No systemic signs of infection
What is moderate non-purulent SSTI?
Systemic signs of infection
What is severe non-purulent SSTI?
Meets two of the four SIRS criteria
What are the four SIRS criteria?
-Temp over 38C or below 36C
-HR over 90
-RR over 24
-WBC over 12k or below 4k
What are some common causative pathogens for non-purulent SSTI?
-Strep spp.
-MRSA if risk factors are present
What are risk factors for MRSA?
-Penetrating trauma
-Evidence of MRSA elsewhere
-Nasal colonization with MRSA
-Intravenous drug use
-SIRS/severe infection
-Failed non-MRSA antibiotic regimen
What is the treatment for mild non-purulent SSTI?
(oral antibiotics)
-Penicillin VK
-Cephalosporin
-Dicloxacillin (not on the market)
-Clindamycin
What is the treatment for moderate non-purulent SSTI?
(IV antibiotics)
-Penicillin
-Ceftriaxone
-Cefazolin
-Clindamycin
What is the treatment for severe non-purulent SSTI?
-Emergent surgical inspection/debridement
-Vancomycin + Zosyn
-Get cultures and susceptibility
Duration of treatment for non-purulent SSTI
5 days
Characteristics of purulent SSTI
-Pus
-Abscesses
-Furuncles
-Carbuncles
What is an abscess?
Collection of pus within the dermis and deeper skin tissues
What is a furuncle?
Small abscess that forms on the hair follicle
What is a carbuncle?
Infection involving several adjacent follicles
Purulent SSTI patient presentation
-Tender
-Red nodules
-Erythema
-Warm to touch
When are cultures recommended for patients with a purulent SSTI?
Recommended for all abscess, carbuncles and patients with systemic signs of infection regardless of severity
What imaging is done for purulent SSTI?
CT/MRI to confirm presence of abscess
What is a mild purulent SSTI?
No systemic signs of infection
What is a moderate purulent SSTI?
Systemic signs of infection
What is a severe purulent SSTI?
Meets SIRS criteria
Common causative pathogens for purulent SSTI
-MRSA
-MSSA
-Strep spp.
Treatment for mild purulent SSTI
Incision and drainage
Treatment for moderate purulent SSTI?
-Incision and drainage
-Get culture and susceptibility
-Empiric treatment then step-down to targeted treatment
Empiric treatment for moderate purulent SSTI?
-Bactrim
-Doxycycline
MRSA targeted treatment for moderate purulent SSTI?
-Bactrim
-Doxycycline
MSSA targeted treatment for moderate purulent SSTI?
-Dicloxacillin (not on market)
-Cephalexin
Treatment for severe purulent SSTI?
-Incision and drainage
-Get culture and susceptibility
-Empiric treatment then step-down to targeted treatment
Empiric treatment for severe purulent SSTI?
-Vanco
-Dapto
-Linezolid
MRSA targeted treatment for severe purulent SSTI?
-Vanco
-Dapto
-Linezolid
MSSA targeted treatment for severe purulent SSTI?
-Nafcillin
-Cefazolin
-Clindamycin
Patient presentation for necrotizing fasciitis
-Profound systemic toxicity
-Change in color of skin to maroon/purple/black
-Crepitus
-Edema
-Severe pain
When are cultures recommended for necrotizing fasciitis?
-Blood cultures are recommended given severity of infection
-Wound cultures will likely be obtained from surgery
What imaging is done for necrotizing fasciitis?
CT/MRI to confirm necrotizing fasciitis (look for gas) or presence of abscess
What pathogen is the number one cause of necrotizing fasciitis?
Strep spp.
Duration of treatment for purulent SSTI
5 days
What is the treatment for necrotizing fasciitis?
-Emergent surgical inspection and debridement
-Get culture and susceptibility
-Empiric antibiotics then step-down to targeted antibiotics after obtaining culture and susceptibility
What is the empiric treatment for necrotizing fasciitis?
Vancomycin + Zosyn
What is the S. pyogenes targeted treatment for necrotizing fasciitis?
Penicillin + clindamycin
What is the polymicrobial treatment for necrotizing fasciitis?
Vancomycin + Zosyn
Duration of treatment for necrotizing fasciitis
-Until further debridement is no longer necessary
-Until patient has improved clinically
-Until fever has been absent for 48-72 hours
Why is clindamycin commonly used to treat SSTI?
It inhibits streptococcal toxin production allowing penicillin to retain its efficacy
What is impetigo?
-Highly contagious superficial skin infection caused by skin abrasions
-Common in children and in hot/humid weather
Impetigo patient presentation
-Small, painless, fluid filled vesicles that can lead to thick golden crusts
-Systemic signs of infection are rare
Should cultures be taken for impetigo?
Recommended to take from pus/exudates but are not required
How do you treat impetigo with few lesions?
Topical mupirocin
How do you treat impetigo with many lesions/outbreak?
-Dicloxacillin or cephalexin
-Strep ONLY: penicillin
-Allergic to penicillin or MRSA: Doxycycline, clindamycin, or bactrim
Patient presentation for cat bites
Deep, sharp puncture wounds
Patient presentation for dog/human bites
Cellulitis signs and symptoms
Should you get blood cultures in animal bites?
They are recommended
Common pathogens in animal bites
-Pasteurella
-Capnocytophaga
Duration of treatment for impetigo with few lesions
5 days
Duration of treatment for impetigo with many lesions/outbreak
7 days
Drug of choice for animal/human bites
Augmentin
Alternative treatment for animal/human bites
Second/third generation cephalosporin + anaerobic coverage
Treatment for animal/human bites in patients with beta-lactam allergy
-Cipro/levofloxacin + anaerobic coverage
-Moxifloxacin
What vaccines should someone get who got a animal/human bite
-Tdap if due
-Sometimes rabies
How long should treatment be for an established animal/human bite infection?
7-14 days
How long should preemptive treatment be for animal/human bites?
3-5 days
When do you give preemptive treatment for animal/human bites?
-Immunocompromised
-Asplenia
-Moderate to severe bites
-Bites on face/hand
-Bites that penetrate joints
