Skin & Soft Tissue: Cellulitis

Cellulitis

Definition

  • Infection of the Skin & Subcutaneous Tissue

Presentation

  • Erythema
  • Edema
  • Warmth
  • Develops Over a Few Days

Most Common Organisms

  • Group A Streptococcus
  • Streptococcus Pyogenes
  • Staphylococcus aureus

Diagnosis

  • Clinical Diagnosis Based on Physical Exam
  • Consider Ultrasound to Rule Out Abscess

Treatment

  • Primary Treatment: Antibiotics for 5-7 Days
    • May Need Longer Course Dependent on Severity
  • Route:
    • Generally Oral is Preferred
    • Indications for IV:
      • Systemic Toxicity (Fever, Tachycardia, Hypotension)
      • Rapid Progression
      • Not Improving or Unable to Tolerate Oral Therapy
      • Proximity to a Prosthetic Device
  • Antibiotic Choice:
    • Indications for Empiric MRSA Coverage:
      • History of MRSA Infection (Not MSSA)
      • Purulence without Drainable Abscess
      • Systemic Toxicity (Fever, Tachycardia, Hypotension)
      • Recent Hospitalization or Surgery
      • Residence in Long-Term Care Facility
      • Hemodialysis
      • HIV Infection
    • Common Choices:
      • No Concern for MRSA: Cephalexin (PO), Dicloxacillin (PO), Cefazolin (IV) or Clindamycin (PO/IV)
      • Concern for MRSA: TMP-SMX/Bactrim (PO), Amoxicillin Plus Doxycycline (PO) or Vancomycin (IV)

Cellulitis 1

Similar Superficial Pathology

Erysipelas

  • Infection Limited to the Outer Skin (Epidermis & Superficial Dermis)
  • Presentation:
    • Fiery Red Erythema
    • Pain
    • Sharp Borders (Well Demarcated)
    • Develops More Rapidly than Cellulitis
  • Most Common Organism: Group A Streptococcus
  • Treatment: Antibiotics

Contact Dermatitis

  • Definition: Localized Skin Inflammation Due to Chemical or Physical Agents
    • Noninfectious
  • Common Causes:
    • Water
    • Detergents
    • Soaps
    • Oxidizing Agents (Bleach or Benzoyl Peroxide)
    • Metals
  • Presentation:
    • Erythema
    • Edema
    • Vesicles or Bullae
    • Pruritis or Burning – Differentiate from Cellulitis
    • Reaction Limited to Site of Contact
  • Treatment:
    • Avoid Offending Agents
    • Moisturizers
    • Consider Topical Corticosteroids – Debated

Erysipelas 2

Contact Dermatitis from a Buprenorphine Patch 3

References

  1. Anderson C. Wikimedia Commons. (License: CC BY-SA-3.0)
  2. L’quourouce P. Wikimedia Commons. (License: CC BY-SA-3.0)
  3. Von Nudeldorf MS. Wikimedia Commons. (License: CC BY-SA-4.0)