The role of primary care prescribers in the diagnosis and management of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections.

Nosocomial infections caused by methicillin-resistant Staphylococcus aureus were first reported in the United States in the early 1960s. Beginning in the 1990s, healthy individuals from the community with no risk factors for resistant bacteria began presenting with methicillin-resistant Staphylococcus aureus infections, acquiring the name "community-associated methicillin-resistant Staphylococcus aureus" (CA-MRSA). CA-MRSA has a tendency to affect the skin and skin structures, generally in the form of abscesses and furuncles, carbuncles, and cellulitis. Cases of invasive infections including bacteremia, endocarditis, and necrotizing pneumonia have also been reported. A patient complaint of a "spider bite" is frequently associated with CA-MRSA. CA-MRSA and the traditional health care-associated methicillin-resistant Staphylococcus aureus are distinguished by their genetic composition, virulence factors, and susceptibility patterns to non-beta-lactam antibiotics. Appropriate management of CA-MRSA skin and skin structure infections includes incision and drainage of infected tissue and appropriate antimicrobial therapy. It has been suggested that when prevalence of CA-MRSA within a community eclipses 10%-15%, empiric use of non-beta-lactam antibiotics with in vitro activity against CA-MRSA be initiated when treating skin and skin structure infections. CA-MRSA retains susceptibility to a range of older antibiotics available in oral formulations such as minocycline, doxycycline, sulfamethoxazole-trimethoprim, moxifloxacin, levofloxacin, and clindamycin. Local susceptibility patterns and individual patient factors should guide the selection of antibiotics.