Diabetic Foot Disease
last authored: April 2012, David LaPierre
last reviewed:
Tom Sargeant, UofT. big into education.
Introduction
Between 15-20% of people with diabetes have foot pathology, accounting for the most days of hospitalizations.
DFU precede amputation by 85%.
AKA 30 day mortality is up to 25% in people over 65.
The Case of...
A 54 year-old woman, with a 20 year history of poorly controlled diabetes, presents to her family physician with a ulcer on the bottom of her foot. It has been present for the past month or so; however, over the past two days, her foot is now painful and red.
Causes and Risk Factors
Bacterial pathogens may include:
- mild: Staph aureus, Streptococcus
moderate or severe infections are normally polymicrobial. Common pathogens include:
- Staph aureus
- Streptococcus
- Enterococcus
- Gram negative bacilli (E coli)
- anaerobes (Peptostreptococcus, Bacteroides, Clostridium)
Pathophysiology
Charcot foot is a collapse of the midfoot bones, with abnormal bony prominences.
Signs and Symptoms
- history
- physical exam
History
History of present illness
- onset
- progression
- trauma
- erythema, warmth
- discharge
- constitutional symptoms: fever, chills, sweats
- pain (OPQRST)
- changes in sensation
Diabetes management
- duration of disease
- previous foot diease
- fasting, postprandial sugars
- last HgbA1C
- macrovascular complications: heart disease, stroke
- microvascular complications: kidney disease, retinopathy, neuropathy
- foot care: last monofilament test, changes in sensation, footwear, claudication
Past medical history
- other co-morbidities
- medications, allergies
- smoking, alcohol, drugs
- family history
Physical Exam
Vitals: fever? systemic evidence of infection
Foot exam
- wound
- ulceration
- thickened nails
- corns, callus, fissures
- biomechanical abnormalities
- 10g monofilament test
- loss of vibration
- footwear
- probe to base of wound
- Charcot foot?
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
As indicated, bloodwork may include:
- CBC
- blood cultures and sensitivity
- curretage and bone biopsy
Diagnostic Imaging
X ray may be done to evaulate bones.
MRI or bone scan can be used to assess for osteomyelitis.
Vascular studies, such as arterial doppler, are warranted if claudication is present or there is other evidence of vascular insufficiency.
Differential Diagnosis
Treatments
Ensuring patient stability is always paramount. As vital signs warrant, provide oxygen and/or IV fluids.
Antibiotics
Proper wound swabbing is important for effective antibiotic coverage.
Mild: trimethoprim/sulfamethoxazole and metronidazole for 2-3 weeks
Moderate (bone/joint involvement): ciprofloxacin and clindamycin for 4-6 weeks
Severe (signficant bone/joint involvement, +/- systemic response): same as above, with imipenem or pipercillin/tazobactam
Patients can be treated as an outpatient, with a PICC line or IV.
Admissions
Wound debridement
Early surgical debridement is of value to remove necrotic tissue and promote healing. Amputation should be considered in severe situations.
Referral
- Vascular supply: vascular surgery, interventional radiology
- Infection.imaging: family medicine, emergency medicine, internal medicine, infectious diseases, microbiology
- Pressure relief: chiropody, occupational therapy, ortho technologists
- Surgical debridement: pastic surgery, orthopedic surgery
Consequences and Course
Resources and References
Canadian Association of Wound Care
Topic Development
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