Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT 33-01: Streptococcal Infections + Key Features Download Section PDF Listen +++ ++ Group A beta-hemolytic streptococci are not normal skin flora Usually result from colonization of normal skin by contact with other infected individuals or by preceding streptococcal respiratory infection + Clinical Findings Download Section PDF Listen +++ ++ Impetigo Focal, vesicular, pustular lesion with a thick, amber-colored crust that has a "stuck-on" appearance Erysipelas Painful superficial cellulitis that frequently involves the face Indurated, slightly elevated, and well demarcated from the surrounding normal skin + Diagnosis Download Section PDF Listen +++ ++ Cultures obtained from skin are usually negative unless there is a wound, pustule, or impetigo, but if positive can help to exclude nafcillin-resistant streptococci Blood cultures are occasionally positive + Treatment Download Section PDF Listen +++ ++ Parenteral antibiotics are indicated for patients with facial erysipelas or evidence of systemic infection Penicillin, 2 million units every 4 hours intravenously, is the drug of choice For severely ill patients or those who have risk factors for staphylococcal infection (eg, injection drug use, wound infection, diabetes) reasonable choices for initial therapy include Nafcillin, 1–2 g every 4–6 hours intravenously, or Cefazolin, 1 g intravenously or intramuscularly every 8 hours In the patient at risk for methicillin-resistant S aureus infection or with a serious penicillin allergy (ie, anaphylaxis), vancomycin, 1000 mg every 12 hours intravenously, or daptomycin, 4 mg/kg intravenously daily, should be used (Table 33–1) Patients who do not require parenteral therapy may be treated with amoxicillin, 500 mg three times daily or 875 mg twice daily orally for 7–10 days A first-generation oral cephalosporin, eg, cephalexin, 500 mg four times daily, or clindamycin, 300 mg orally three times daily, is an alternative to amoxicillin Maintenance therapy with penicillin, 250 mg orally twice daily (for at least 1 year), can reduce the likelihood of relapse of recurrent cellulitis in the leg ++Table Graphic Jump LocationTable 33–1.Empiric treatment of common skin and soft tissue infections (SSTIs).View Table||Download (.pdf) Table 33–1. Empiric treatment of common skin and soft tissue infections (SSTIs). SSTI Type Common Pathogens Treatment Purulent (abscess, furuncle, carbuncle, cellulitis with purulence) Staphylococcus aureus Incision and drainage is the primary treatment Consider the addition of antibiotics in select situations1 Oral antibiotic regimens Cephalexin 500 mg four times daily or dicloxacillin 500 mg four times daily Clindamycin 300–450 mg three or four times daily2 or one double-strength tablet of trimethoprim-sulfamethoxazole twice daily2 or doxycycline 100 mg twice daily2 Intravenous antibiotic regimens3 Cefazolin 1 g three times daily or nafcillin 1–2 g four to six times daily Vancomycin 1 g twice daily2 or daptomycin 4 mg/kg once daily2 Nonpurulent (cellulitis, erysipelas) Beta-hemolytic streptococci (S aureus less likely) Oral antibiotic regimens Cephalexin 500 mg four times daily or dicloxacillin 500 mg four times daily Clindamycin 300–450 mg three or four times daily2 or amoxicillin 875 mg twice daily plus one double-strength tablet of trimethoprim-sulfamethoxazole twice daily2 Intravenous antibiotic regimens3 Cefazolin 1 g three times daily or nafcillin 1–2 g four to six times daily Vancomycin 1 g twice daily2 or daptomycin 4 mg/kg once daily 1Antibiotic therapy should be given in addition to incision and drainage for purulent skin and soft tissue infections if the patient has any of the following: severe or extensive disease, symptoms and signs of systemic illness, purulent cellulitis/wound infection, comorbidities and extremes of age, abscess in area difficult to drain or on face/hand, associated septic phlebitis, or lack of response to incision and drainage alone.2Regimens with activity against methicillin-resistant S aureus.3Other regimens approved by the FDA for treatment of complicated skin and soft tissue infections include tigecycline 100 mg intravenously once followed by 50 mg intravenously twice a day, ceftaroline 600 mg twice a day for 7–14 days, dalbavancin 1 g intravenously on day 1 and then 500 mg intravenously on day 8, oritavancin as a single intravenous dose of 1200 mg, and telavancin 10 mg/kg intravenously once daily for 7–14 days.