Key Points ÎComplicated infections are:
OR > Superficial infections or abscesses in sites, such as the rectal area, where the risk of
anaerobic or gram-negative pathogen involvement is higher.
ÎSkin and soft tissue infections are caused by a variety of pathogens, including aerobic gram-positive and gram-negative organisms, as well as certain unique pathogens acquired in specific settings.
> Overall, Staphylococcus aureus is the pathogen most frequently isolated from complicated SSTIs.
ÎIn many regions and communities, a rapid rise in CA-MRSA has occurred, with this organism now being the single most frequent pathogen in SSTIs.
> This pathogen typically is associated with the production of virulence factors not common to methicillin-sensitive S. aureus (MSSA) isolates or to hospital-associated HA-MRSA isolates, including the Panton-Valentine leukocidin (PVL) toxin.
Assessment Non-necrotizing Cellulitis
ÎThese superficially spreading infections involving the skin are caused almost exclusively by β-hemolytic streptococci.
ÎAntibiotic therapy: for moderate to severe infections, parenteral penicillin is the agent of choice (1C).
ÎTreatment failures may occur if β-lactam agents are used alone in severe cases (1C).
ÎProtein synthesis-inhibitory agents alone—eg, clindamycin or a macrolide— or in combination with cell wall-active agents should be given in severe cases (1B/C).
ÎIncreasing macrolide resistance among streptococci introduces concern about the value of these agents (1C).
ÎOther regimens that may be considered are antistaphylococcal penicillins, cefazolin, and ceftriaxone (2B/C).
Abscesses ÎSimple abscesses may respond to incision and drainage (I&D) alone (2B).
ÎMore complex abscesses and those with substantial cellulitis require adjuvant antibiotic therapy (1C).
ÎInadequate response to therapy should prompt evaluation of the adequacy of drainage (1C).
ÎEmpiric antibiotic therapy should be directed toward the most likely pathogens (1B).
ÎAgents directed at CA-MRSA should be considered in most settings (1B).
ÎSuspected polymicrobial infections should be managed with coverage of enteric gram-negative and anaerobic pathogens (1B).
> Those involving deeper soft tissues necessitating surgical intervention, such as infected ulcers, burns, major abscesses, or an underlying disease state that complicates the response to treatment (eg, peripheral arterial disease, chronic kidney disease, diabetes mellitus)
