Severity Findings Bacteria Treatment
Mild Typical cellulitis
No risk factors
No systemic symptoms
Streptococci Oral
  • PCN
  • Dicloxacillin
  • Cephalosporins
  • Clindamycin
Moderate Typical cellulitis
No risk factors
Systemic symptoms
Streptococci
MSSA
  • Intravenous
  • PCN
  • Ceftriaxone
  • Cefazolin
  • Clindamycin
Severe Risk factors
  • Penetrating trauma
  • Evidence of MRSA infection elsewhere
  • Injection drug use
Hypotension
Signs of necrotic infection
Fail outpatient treatment
Deeper signs of infection 		Streptococci
MSSA
Gram negative
Anaerobes
Intravenous
  • Vancomycin
  • Piperacillin/Tazobactam
Early surgical consultation if concern for necrotizing infection

Raise affected extremity
Antibiotic duration: 5 days, continue to 10 days if not improving
Lower extremity cellulitis: check interdigital toe space and treat if abnormal

“Systemic symptoms” = temp > 38°C, tachycardia (HR > 90), tachypnea (RR > 20 or PaCO2 < 32)