Overview of Bacterial Skin Infections
Bacterial skin infections can be classified as skin and soft tissue infections (SSTI) and acute bacterial skin and skin structure infections (ABSSSI). SSTI include
ABSSSI are complex bacterial skin infections. They include
Major cutaneous abscesses (>75 cm2 edema, erythema, and induration)
The primary pathogens in SSTI are Streptococcus and Staphylococcus species, including methicillin-resistant Staphylococcus aureus (MRSA). MRSA is the most common pathogen in the US. More than half of community-associated SSTI treated in the US were attributable to MRSA USA300 subtype in the early 2010 decade. However, the proportion of cases attributed to MRSA differs substantially elsewhere in the world. Particularly because MRSA can be resistant to multiple antibiotics, recommended antibiotics for bacterial skin and soft tissue infections depend largely on local prevalence and resistance patterns of MRSA.
The Infectious Diseases Society of America (IDSA) recommends that mild to moderate nonpurulent ABSSSI be treated with a beta-lactam or clindamycin as presumptive coverage for streptococci. Coverage for MRSA should be considered as well in patients at risk (eg, after penetrating trauma, with suspected nasal MRSA carriage, or who use IV drugs). Purulent ABSSSI are considered severe if patients have signs of systemic toxicity (eg, fever, tachycardia, tachypnea, delirium, leukocytosis). If so, Gram stain, culture, and antibiotic therapy are recommended. The antibiotic of choice is usually vancomycin. However, several alternatives are available.