Skin and Soft Tissue Infections

University of Pennsylvania Medical Center Guidelines for Antibiotic Use

SKIN AND SOFT TISSUE INFECTIONS

Clinical Setting	Empiric Treatment	Likely Pathogens	Definitive Treatment	Dosage Regimen	Duration
Cellulitis
Extremities Normal Host	cefazolin¹	S. aureus group A streptococcus	same as empiric	500mg IV q 8 hour	7-10 days²
Diabetic Host (including diabetic foot)	TMP/SMX + metronidazole^3,4	polymicrobial	same as empiric	TMP/SMX 8-10mg/kg/day TMP IV/PO in 3-4 divided doses metronidazole 500mg IV/PO q 12 h	14 days²
Decubitus Ulcer⁵	cefazolin¹	polymicrobial	same as empiric	cefazolin 500mg IV q 8 hour	7-10 days²
Wound Infection⁶ Trauma (soft tissue wound, no bowel or bone involvement)	cefazolin¹ + metronidazole³	polymicrobial (consider Pseudomonas spp., Aeromonas spp. if trauma associated with water)	base therapy upon culture & sensitivity results	cefazolin 500mg IV q 8 hour metronidazole 500mg IV/PO q 12 h	7 days

^{1If beta-lactam allergy use
clindamycin or trimethoprim sulfamethoxazole; if MRSA-use
vancomycin}

^{2Can switch to oral therapy once clinical improvement
occurs}

^{3Not for aggressive anaerobic cellulitis}

^{4Metronidazole: use if foul odor present}

^{5Adequate wound debridement required; antibiotics only
necessary for surrounding cellulitis}

^{6Adequate wound debridement required}

SKIN AND SOFT TISSUE INFECTIONS

Clinical Setting	Empiric Treatment	Likely Pathogens	Definitive Treatment	Dosage Regimen	Duration
Wound¹Post-operative- GI/GU	ampicillin/ sulbactam²	S. aureus	nafcillin³ or cefazolin³	2gm IV q 4-6 hour 500mg IV q 8 hour	10 days¹
		Streptococcus spp.	ampicillin	1gm IV q 6 hour
		Enterococcus spp.⁴	ampicillin + gentamicin	2gm IV q 6 hour peak conc. of 3-4 mcg/ml
		Enterobacteriaceae	TMP/SMX	8-10mg/kg/day TMP IV in 3-4 divided doses
		P. aeruginosa	piperacillin + gentamicin	4gm IV q 6 hour see this link
		anaerobes	metronidazole (may need to add to above regimen)	500mg IV q 12 hour
Post-operative- sternal⁵	vancomycin + gentamicin	S. aureus	nafcillin³or cefazolin³	2gm IV q 4-6 hour 500mg IV q 8 hour	1-6 weeks depending upon clinical setting
		coagulase negative staphylococcus	vancomycin	see this link
		Streptococcus spp.	ampicillin	1gm IV q 6 hour
		Enterobacteriaceae	TMP/SMX	TMP/SMX 8-10mg/kg/day TMP IV/PO in 3-4 divided doses
Bites
Animal/Human^1,6no bone or joint involvement	amoxicillin/clavulanic acid⁷	depends on the animal	same as empiric	500mg PO q 8 hour	7-10 days
bone and joint involvement	ampicillin/sulbactam⁷	depends on the animal	change empiric therapy to amoxicillin/clavulanic acid after adequate debridement and microorganism identification	ampicillin/sulbactam: 1.5 gm IV q 6 hour	Depends on the extent of disease

¹Adequate wound debridement required

^{2Ampicillin/sulbactam dosage
Regimen: 1.5 gm IV q 6 hour}

^{3If beta-lactam allergy-use
clindamycin or trimethoprim/sulfamethoxazole; if
MRSA-vancomycin}

^{4Review susceptibilities-30% of
isolates multidrug resistant}

^{5Rule-out osteomyelitis}

⁶Patient should receive tetanus booster if series not up to date

^{7Penicillin allergy: human bite-erythromycin 500mg IV/PO q 6hr; animal
bite-doxycycline 100mg IV/PO q 12hr}

updated 9/28/04 by Lori LaRosa

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