Based upon the International
Consensus on Diagnosing and
Treating the Infected
Diabetic Foot and prepared
by the IWGDF working group
on diagnosing and treating
the infected diabetic foot
in 2003
The Working Group recognizes
that the availability of
diagnostic procedures and
antimicrobial agents will
vary greatly in different
clinical sites and in
different countries. While
the basic principles of
treating diabetic foot
infections are the same in
all situations, they have
provided guidance that must
be adapted to local
circumstances.
Pathophysiology
Foot infections in
persons with diabetes
usually begin with a
break in the skin,
especially a neuropathic
ulceration.
This allows
colonizing skin flora to
invade the skin and
subcutaneous tissues.
Diagnosis
Diagnose wound
infections clinically
(recognizing that the
inflammatory response
may be mitigated by
diabetic complications),
by the presence of
purulent secretions or
local evidence of
inflammation, or
occasionally systemic
toxicity.
Laboratory tests,
including cultures, may
suggest but do not
establish the presence
of infection, with the
exception of reliably
obtained deep bone
cultures in suspected
osteomyelitis.
Classification
Assess the severity
of the infection by
examining the wound,
limb, and the overall
status of the patient,
to determine the
appropriate approach to
treatment.
Classifying
infections by their
severity helps determine
the site, type and
urgency of treatment.
Microbiology
1. Cultures
Obtaining proper
specimens for
culture is
usually
advisable, to
help select an
appropriate
antibiotic
regimen.
Cultures may not
be necessary in
previously
untreated, mild
infections.
Take wound
cultures by
obtaining tissue
(by curettage or
biopsy) of the
debrided wound
base or by
aspirating pus,
rather than by
swabbing. If
swabs are the
only option,
take them from
the ulcer base
after
debridement, and
process quickly.
Consider
obtaining blood
cultures from
systemically
toxic patients
and consider
bone cultures
from patients
with
osteomyelitis
2. Etiologic agents
Aerobic
gram-positive
cocci
(especially
staphylococci)
are usually the
initial, often
the only, and
almost always
the most
frequently
isolated
pathogens in
soft tissue and
bone infections.
Gram-negative
and anaerobic
bacteria are
commonly
isolated, but
usually as part
of a
polymicrobial,
chronic or
necrotic
infection.
Non-antimicrobial treatment
Consult a diabetic
foot care team or
specialist, where
available.
Correct any
metabolic derangements,
optimize wound care, and
assess vascular status.
Hospitalize
patients: with a severe
infection, needing
multiple or complex
diagnostic or surgical
procedures; having
critical foot ischemia;
needing intravenous
therapy; or unlikely to
comply with therapy.
In case of severe
infection, consult
appropriate specialists
promptly for any
necessary invasive
diagnostic or surgical
procedures.
Antimicrobial therapy
1. General
principles
Prescribe
for all
clinically
infected wounds
immediately, but
not for
uninfected
wounds.
Select the
narrowest
spectrum therapy
possible for
mild or moderate
infections.
Choose
initial therapy
based on the
commonest
pathogens and
known local
antibiotic
sensitivity
data.
Adjust
(broaden or
constrain)
empiric therapy
based on the
culture results
and clinical
response to the
initial regimen.
2. Specific choices
(see below)
Cover
staphylococci
and streptococci
in almost all
cases.
Broaden the
spectrum if
necessary based
on the clinical
picture, or
previous culture
or current
Gram-stained
smear results.
Topical
therapy for mild
superficial
infections has
not been
adequately
studied; oral
therapy is
effective for
most mild to
moderate
infections;
parenteral
therapy (at
least initially)
is advisable for
severe
infections.
Choose
agents that have
demonstrated
efficacy in
treating
complicated skin
and soft tissue
infections.
These include
semi-synthetic-penicillins,
cephalosporins,
penicillin-?-lactamase
inhibitors,
clindamycin,
fluoroquinolones,
carbapenems, and
oxazolidinones.
Treat soft
tissue
infections for
1-2 weeks if
mild infections,
and about 2-4
weeks for most
that are
moderate and
severe. When the
clinical
evidence of
infection has
resolved
antibiotic
therapy can be
stopped.
Appendix
Suggested systemic
antibiotic regimens for
treating diabetic foot
infections
Severity of
Infection
Usual
Pathogen(s)
Potential
Regimens
Non-severe (oral for
entire course)
No complicating
features
GPC
S-S pen; 1 G Ceph
Recent antibiotic
therapy
GPC +/- GNR
FQ, ß-L-ase
Drug allergies
Clindamycin; FQ; T/S
Severe (intravenous
until stable, then
switch to oral
equivalent)
No complicating
features
GPC2 +/- GNR
ß-L-ase; 2/3 G Ceph
Recent
antibiotic/necrosis
GPC + GNR/anaerobes
3/4 G Ceph; FQ +
Clindamycin
Life-threatening
(prolonged
intravenous)
MRSA unlikely
GPC + GNR +
anaerobes
Carbapenem;
Clindamycin
Aminoglycoside
MRSA likely
Glycopeptide or
linezolid + 3/4 G
Ceph or FQ +
metronidazole
1Given at usual
recommended doses for
serious infections; modify
for azotemia, etc.; based
upon theoretical
considerations and available
clinical trials
2 A high local
prevalence of
methicillin-resistance among
staphylococci may require
using vancomycin or other
appropriate
anti-staphylococcal agents
active against these
organisms
