Skin and Soft Tissue Infections

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Skin and Soft Tissue Infections
 
Epidemiology 

• Cellulitis 2.3 million visits in the ED annually
• 15% get admitted
• Up to 30% of diagnosed cellulitis is really a “cellulitis mimic”

 
Important Aspects of your History

• Travel? Water exposure?
• Recent trauma or bug bite?
• Recent antibiotics?
• Immunocompromised? Diabetes w/ complications (neuropathy, sugar uncontrolled, etc)?

 
The Mimics

• Venous stasis
• PAD
• DVT or superficial thrombophlebitis
• Dermatosclerosis
• Diabetic myonecrosis
• Lymphedema
• Contact dermatitis
• Necrotizing fasciitis 

 
Workup

• Good history and physical exam
• Always ultrasound to look for purulence or abscess
• Labs largely unhelpful

 
Treatment

• Simple cellulitis w/out purulence = Keflex (consult local antibiogram)
• Cellulitis w/ purulence = Keflex plus Staph Aureus coverage
• Abscess – Drain and only give antibiotics in special circumstances

 
“Special” cellulitis

• Perichondritis
  • Needs coverage for pseudomonas
• Bites – think Pasteurella
  • Augmentin
• Water exposure
  • Vibrio– doxycycline
  • Aeromonas– Rocephin, Bactrim, or a fluoroquinolone. 
• Orbital cellulitis
  • IV abx, CT scan
• Unvaccinated children
  • H. influenzacellulitis associated with 90% bacteremia
• Abscess
  • Needs drainage
  • Bactrim if abscess > 5cm, patient immunocompromised, in axilla or groin

 
 
Necrotizing fasciitis +/- Toxic Shock Syndrome 

• When patient presents in extremis, the diagnosis is easy
• Helpful physical exam findings
  • Pain out of proportion
  • Pain outside the margin of the rash
  • Bullae, skin necrosis, pallor, hypoesthesia, crepitus are late findings
• Labs are unhelpful and cannot be relied upon until it is too late
• Resuscitate and give Vancomycin, Zosyn, and Clindamycin
  • Clindamycin needed for decreased toxin release in setting of toxic shock syndrome. Always give with first wave of antibiotics if you are treating necrotizing fasciitis
• Imaging is not universally helpful
• Very tough diagnosis, you need a high index of suspicion
• Consult surgery quickly if suspicious, you will need source control