Source: Fish DN, Pendland
SL, Danziger LH. Skin and Soft-Tissue Infections. In: DiPiro, JT,
Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy:
A Pathophysiologic Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=8002378.
Accessed July 21, 2012.
- Foot infections in patients with diabetes
- Three types:
- Deep abscesses
- Cellulitis of the dorsum
- Mal perforans ulcers
- Begins with local bacterial invasion and is polymicrobic
(average of 2.3–5.8 isolates per culture).
- Most common pathogens: Staphylococci (especially S. aureus) and streptococci
- Gram-negative bacilli and anaerobes occur in 50% of
- Key factors in development of diabetic foot problems (may
occur in isolation or together):
- Angiopathy and ischemia
- Immunologic defects that impair wound healing
- One of most common diabetes complications, responsible
for up to 20% of all hospitalizations of diabetics.
- Optimize blood glucose control.
- Encourage daily patient self-examination of feet.
- Examine feet at every physician visit.
- Uncontrolled blood glucose
- Peripheral neuropathy
- Infections often more extensive than they initially appear.
- Clinical signs of infection may not be present secondary to
angiopathy and neuropathy.
- Swelling or erythema in foot (patient unaware of pain
due to peripheral neuropathy)
- Presence of pus
- Draining sinuses
- Temperature: normal or mildly elevated
- Lesions vary in size when present.
- Four-smelling odor suggests anaerobic organisms.
Means of Confirmation
- Culture and sensitivities
- Obtain specimen
from deep culture, preferably expressed pus from wound base.
- Culture for aerobic and anaerobic organisms.
- Assess for osteomyelitis via radiograph, bone scan, or
both, as appropriate
- Surgical debridement to obtain samples for culture and
- Preserve as much normal limb function as possible.
- Prevent infectious complications.
- Most infections successfully treated on outpatient basis
with wound care and antibiotics.
- Maximize glycemic control to ensure optimal wound healing.
- Thoroughly debride necrotic tissue, with wound drainage
and amputation as required.
- Wounds must be kept clean and dressings changed 2–3
- Restrict patient initially to bedrest for leg elevation and
control of edema, if present.
- Adequate pressure
relief from foot wound crucial to healing process.
- Antimicrobial therapy (Tables 1 and 2)
uncomplicated infections treated with oral outpatient antibiotics
such as amoxicillin-clavulanate.
- Does not cover P. aeruginosa
- Fluoroquinolones with metronidazole or clindamycin reasonable
- Treat 7–14 days.
- Moderate to severe infections
with broad-spectrum parenteral antimicrobials plus appropriate medical
and/or surgical management often effective (including those
with presence of osteomyelitis).
- Initial therapy
similar to that for polymicrobic cellulitis with anaerobes.
- Treat 2–4 weeks.
- Treat 6–12 weeks if osteomyelitis is present.
- Vancomycin used frequently in severe infections with gram-positive
pathogens. With increasing staphylococcal resistance, linezolid,
quinupristin/dalfopristin, daptomycin, and tigecycline