Skin and Soft Tissue Infections

Cellulitis

• Deep dermis and subcutaneous tissue
• Poorly demarcated borders, erythema, edema, warmth, fever
• Mostly caused by streptococcal species, sometimes by staphylococcus species
• Treatment
  • Purulent
    • Systemic toxicity/severe infection: IV Vancomycin (or Daptomycin)
    • No systemic toxicity: Treatment varies dependent upon multiple factors. Ultimately, the patient needs coverage for at least MRSA (Doxycycline, clindamycin, trimethoprim-sulfamethoxazole) with potential need for additional coverage if there is significant necrosis or if the lesion is perioral or perirectal.
  • Non-purulent
    • MRSA risk factors (group/nursing homes, recent antibiotic use, IV drug use):
      • Systemic toxicity/severe infection: IV Vancomycin (or Daptomycin)
      • No systemic toxicity: Amoxicillin + doxycycline, or clindamycin
    • No MRSA risk factors: Cephalexin, dicloxacillin, clindamycin

Erysipelas

• Superficial dermis
• Sharply demarcated borders, fevers, chills, malaise, headache
• Almost exclusively streptococcal species
• Treatment
  • Systemic symptoms (fevers, chills, etc.): Cefazolin or Ceftriaxone
  • No systemic symptoms: Amoxicillin, Clindamycin, Cephalexin

Impetigo

• Epidermis
• Papules -> vesicles surrounded by erythema -> pustules with thick golden crust. May or may not have bullae
• Primarily caused by staphylococcal species, sometimes by streptococcal species
• Treatment:
  • Topical mupirocin
  • PO cephalexin or dicloxacillin if multiple clusters