Acute bacterial skin and skin structure infections (ABSSSI) have become a challenging medical problem associated with high direct and indirect costs to both the medical system and society. These types of infections are responsible for more than 750,000 hospitalizations per year, representing a 17.3% increase in hospitalized ABSSSI patients from 2005 to 2011.
ABSSSI includes the following diagnoses:
- Cellulitis/erysipelas: A diffuse skin infection characterized by spreading areas of redness, edema, and/or induration
- Wound infection: An infection characterized by purulent drainage from a wound with surrounding redness, edema, and/or induration
- Major cutaneous abscess: An infection characterized by a collection of pus within the dermis or deeper that is accompanied by redness, edema, and/or induration
These skin and skin structure infections, if left untreated can cause potentially life-threatening infections in bones, joints, surgical wounds, the bloodstream, heart valves and lungs.
Guidelines issued in 2010 recommend surgical debridement or drainage of skin and skin structure infections and, where appropriate, initial empiric, broad-spectrum antibiotic therapy pending culture results. Conditions where antibiotic therapy is recommended include:
- Large abscesses surrounded by extensive cellulitis, or accompanied by signs and symptoms of systemic illness
- Abscesses associated with severe or extensive disease (e.g., multiple sites of infection) or rapid progression in presence of associated cellulitis
- Abscesses associated with comorbidities, immunosuppression, septic phlebitis, or extremes of age
- Abscesses in an area difficult to drain (e.g., face, hand, genitalia)
- Lack of response to incision and drainage alone
One of the main challenges in treating ABSSSI is antibiotic resistance. In recent years, there has been a significant increase in the prevalence of severe ABSSSI requiring hospital intervention caused by antibiotic-resistant pathogens, in particular methicillin-resistant Staphylococcus aureus (MRSA) strains. Beginning in the mid-1990s, the prevalence of MRSA shifted from healthcare-associated MRSA (HA-MRSA) to community-associated MRSA (CA-MRSA) strains. CA-MRSA is now the leading identifiable cause of purulent skin and soft tissue infections in emergency department patients in the United States. Typically, upon hospitalization, a patient will be treated for an antibiotic resistant ABSSSI with one or more intravenous antibiotic.