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Education Material for Health Care Professionals: Book Version

THE FEET AND DIABETES

The overall risk of an individual developing a diabetic foot ulcer is determined by a combination of factors. In general, the risk is higher if:

Neuropathy is more severe (because more sensation is lost)
Peripheral vascular disease is more severe (because there is less circulation to bring enough oxygen to repair tissue damage)
There are coexisting abnormalities of the shape of the foot which make the local effects of neuropathy or vascular disease more severe (because it increases local pressure and callus)
The person is unable to practise reasonable self care to maintain general condition of the feet and to prevent trauma (because there are more chances of damaging the feet)
The diabetic control is very poor (because of susceptibility to infection and poor wound healing)
There is a past history of foot ulceration due to diabetes (because the above factors often persist)

INFECTIONS

At the same time, one has to treat any infection at the earliest so that it does not proceed to a more severe form of morbidity. “Nip it in the bud” as they say!

The clinical diagnosis of infection usually consists of three aspects.

(1) Systemic signs of fever and leukocytosis.

(2) Classic signs of inflammation around the ulcer (eg, heat, redness, edema, and pain); and

(3) Presence of purulent discharge from the ulcer;

It should be realized that due to the presence of varying degrees of nerve and arterial involvement, one may not see these “classic” signs.  Pain and tenderness may be absent because of neuropathy. The response to injury in skin includes a local vasodilation mediated by sensory nerve fibers, which are impaired in diabetic neuropathy. Intact tissue responds to bacterial infection by increasing blood flow >20-fold in the area around the infection. However, erythema or redness may be absent in the diabetic foot because of the inability of the foot to increase its blood supply in response to infection. Furthermore, it is now established that up to 50% of patients with deep foot infections will not have leukocytosis or fever. Thus, one cannot wait for the classical signs before initiating management in all patients.

Principles of  treatment

Treating Cellulitis

Empiric Antibiotic therapy

Most of the foot infections are caused by mulitimicobrial  involvement. Thus, empiric treatment should cover Gram- negative aerobic as well as an aerobic organisms. The antibiotic chosen should be bactericiadal as opposed to bacteriostatic. In general, bacteriostatic antibiotics require an intact immune system to function properly. The latter is often compromised in a person with diabetes.

Selected empirical antibiotic regimens for mild and non–limb-threatening infections
Oral agents Topical agents
Cephalexin Silver sulfadiazine
Cefdinir Silver powder, gels
Amoxicillin-clavulanate Mafenide acetate
Clindamycin Ciprofloxacin drops
Dicloxacillin Mupirocin
Ciprofloxacin, levofloxacin Gentamicin
Trimethoprim-sulfamethoxazole Bacitracin
Linezolid Cadexomer iodine

Aminoglycosides should not be used in combination therapy, if possible. In diabetic patients, who may have some degree of underlying nephropathy, the potential toxic effects of these agents is a prime concern, especially since less toxic alternatives are available. In addition, aminoglycosides are inactivated in an acidic environment, such as that found in abscess cavities. They have minimal penetration into bone, thus making them a poor choice for patients with osteomyelitis.

Later, the antibiotic choice would depend on the culture and sensitivity reports.

A patient who presents with mild infection should be closely monitored and if healing does not take place or the conditions worsens, it would be much better to refer the patient  to people specializing in managing such problems.

Any person presenting with more serious infections or an abcess or ulcer should immediately be referred to others well versed in this management without wasting precious time.

But coming to the point which was made initially, an ounce of prevention is still better than tons of treatment no matter how advanced these may be!

It is absolutely essential that all of us teach our patients the “Do’s and Don’ts” of foot care!

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