Skin and Soft Tissue Infections (SSTI) Flashcards
When would wound cultures be obtained for skin and soft tissue infections?
- purulent infections
- necrotizing infections
When would blood cultures be obtained for skin and soft tissue infections?
- severe infections
- intravenous drug use (IVDA)
When would imaging be obtained for skin and soft tissue infections?
necrotizing (deep) infections= CT scans
What is a purulent infection?
- cutaneous abscesses, collection of pus within the dermis and deeper skin tissue
- furuncles and carbuncles
- folliculitis
What is the presentation of a purulent infection?
- tender, red nodules
- signs of erythema
- systemic signs (fever, chills, malaise)- carbuncles and abscesses only
What pathogens are respondsible for purulent infections?
- staphylococcus aureus (MRSA)
- if patient has significant water exposure, pseudomonas aeruginosa
What is the empiric treatment for severe purulent infections?
- vancomycin
- daptomycin
- linezolid
- televancin
- ceftaroline
What is the empiric treatment for moderate purulent infection?
- trimethoprim/sulfamethoxole
- doxycline
What is the duration of therapy for purulent infections?
5 days (minimum)
What is a non-purulent infection?
involves epidermis and dermis, history of wound from minor trauma, abrasion, ulcer, or surgery
- cellulitis
- erysipelas
What is the presentation of non-purulent infections?
- fevers, chill, malaise
- hot and painful to the touch
- systemic symptoms common
- non-elevated lesions with poorly defined margins
- involvement of regional lymphatic system
What pathogens are respondsible for non-purulent infections?
- group A strep (streptococcus pyogenes)
- staphylococcus aureus (MRSA coverage for penetrating trauma, IV drug use, purulent drainage, MRSA infection elsewhere)
When should MRSA be empirically covered for non-purulent infections?
- penetrating trauma
- IV drug use
- purulent drainage
- MRSA infection elsewhere
When would a purulent infection be classified as severe?
- failed inscision & drainage and failed PO antibiotics
- immunocompromised
- SIRS or sepsis (2/4 of the following: temp >38C or 36C, HR > 90bpm, RR > 24bpm, WBC > 12K or <4K)
When would a non-purulent infection be classified as severe?
- failed PO antibiotics
- immunocompromised
- SIRS or sepsis (2/4 of the following: temp >38C or 36C, HR > 90bpm, RR > 24bpm, WBC > 12K or <4K)
What is the treatment for necrotizing infections?
aggressive surgical intervention and antibiotics
medical emergency!
What is the presentation of necrotizing infections?
- marked systemic toxicity
- change in skin color to maroon or purple/black as progresses
- bullae
- crepitus
- cutaneous anesthesia
- edema beyond the margins of erythema
What pathogens are respondsible for necrotizing infections?
- group A streptococcus (S. pyogenes)
- staphylococcus aureus (MRSA)
- clostridium perfringens
What is the treatment of necrotizing infections?
- extended spectrum beta lactam= piperacillin/tazobactam, cefepime, carbapenem
- clindamycin
- vancomycin
What is the purpose of using clindamycin in the treatment of necrotizing infections?
INOCULUM EFFECT
necrotizing soft tissue infections have large bacterial burden and clindamycin efficacy is not affected by the size of bacterial burden unlike beta lactams which has decreased efficacy when bacteria is rapidly dividing. clindamycin also inhibits streptococcus toxin production
What is the treatment for osteomyelitis?
same as necrotizing infections, but longer duration of therapy to 4-6 weeks
