Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 33-04: Staphylococcus aureus Infections + Key Features Download Section PDF Listen +++ ++ Localized erythema with induration and purulent drainage Abscess formation Gram stain of pus shows gram-positive cocci in clusters + Clinical Findings Download Section PDF Listen +++ ++ May begin around one or more hair follicles, causing folliculitis May become localized to form boils (or furuncles) May spread to adjacent skin and deeper subcutaneous tissue (ie, a carbuncle) Deep abscesses involving muscle or fascia may occur, often in association with a deep wound or other inoculation or injection Necrotizing fasciitis has been reported with community strains of methicillin-resistant S aureus (MRSA) + Diagnosis Download Section PDF Listen +++ ++ Cultures of the wound or abscess material almost always yields the organism In patients with systemic signs of infection, blood cultures should be obtained because of potential bacteremia, endocarditis, osteomyelitis, or metastatic seeding of other sites Patients who are bacteremic should have blood cultures taken early during therapy to exclude persistent bacteremia, an indicator of severe or complicated infection + Treatment Download Section PDF Listen +++ ++ Proper drainage of abscess fluid or other focal infections is the mainstay of therapy Incision and drainage alone is highly effective for the treatment of most uncomplicated cutaneous abscesses A small benefit can be obtained from the addition of antimicrobials following incision and drainage. In areas where methicillin-resistance among community S aureus isolates is high, recommended oral antimicrobials agents include Clindamycin, 300 mg three times daily Trimethoprim-sulfamethoxazole, given in two divided doses based on 5–10 mg/kg/day of the trimethoprim component Doxycycline or minocycline, 100 mg twice daily When the risk of methicillin-resistance is low or methicillin-susceptibility has been confirmed by testing of the isolate, consider Dicloxacillin or cephalexin, 500 mg four times a day For complicated infections with extensive cutaneous or deep tissue involvement or fever, initial parenteral therapy is often indicated When methicillin resistance rates are high (above 10%) empiric therapy with vancomycin, 1 g intravenously every 12 hours, is a drug of choice For infections caused by methicillin-susceptible isolates Cefazolin 1 g intravenously or intramuscularly or A penicillinase-resistant penicillin such as nafcillin or oxacillin in a dosage of 1.5 g every 6 hours intravenously For treatment of skin and skin-structure infections Linezolid, 600 mg orally or intravenously twice a day for 10–14 days Effective for MRSA However, considerable cost makes it an unattractive choice for most routine outpatient infections Other alternatives Tedizolid, 200 mg orally once daily for 6 days Daptomycin, 4 mg/kg once daily intravenously for 7–14 days Tigecycline, 100 mg intravenously once, followed by 50 mg intravenously twice a day for 7–14 days Ceftaroline, 600 mg intravenously twice a day for 7–14 days Dalbavancin, a single intravenous dose of 1500 mg Oritavancin, 1200 mg as a single intravenous dose Telavancin, 10 mg/kg intravenously once daily for 7–14 days Delafloxacin, 450 mg orally or 300 intravenously twice daily for 5–14 days Duration of therapy Total duration of therapy for soft tissues infections will depend on clinical response and effectiveness of drainage/debridement Courses of 7 days with early transition to oral therapy are effective in many cases