Diabetic Foot Infections

Definition

Diabetic foot infections are infections that can develop in the skin, muscles, or bones of the foot as a result of the nerve damage and poor circulation that is associated with diabetes.

Description

People who have diabetes have a greater-than-average chance of developing foot infections. Because a person who has diabetes may not feel foot pain or discomfort, problems can remain undetected until fever, weakness, or other signs of systemic infection appear. As a result, even minor irritations occur more often, heal more slowly, and are more likely to result in serious health problems.

With diabetes, foot infections occur more frequently because the disease causes nervous system changes and poor circulation. Because the nerves that control sweating no longer work, the skin of the feet can become very dry and cracked, and calluses tend to occur more frequently and build up faster. If not trimmed regularly, these calluses can turn into open sores or ulcers. Because diabetic nerve damage can cause a loss of sensation (neuropathy), if the feet are not regularly inspected, an ulcer can quickly become infected and, if not treated, may result in the death of tissue (gangrene ) or amputation.

The risk of infection is greatest for people who are over the age of 60 and for those who have one or more of the following:

• poorly controlled diabetes
• foot ulcers
• laser treatment for changes in the retina
• kidney or vascular disease
• loss of sensation (neuropathy)

Causes and symptoms

Bacteria can cause an infection through small cracks (fissures) that can develop in the dry skin around the heel and on other parts of the foot or through corns, calluses, blisters, hangnails, or ulcers. If not treated, the bacterial infection can destroy skin, tissue, and bone or spread throughout the body.

Common sites of diabetic foot infections include the following:

• blisters, corns, or callouses that bleed beneath the skin
• bunions, hammertoes, or other abnormalities in the bones of the foot
• scar tissue that has grown over the site of an earlier infection
• foot ulcers caused by pressure, nerve damage, or poor circulation (Ulcers occur most often over the ball of the foot, on the bottom of the big toe, or on the sides of the foot due to poorly fitting shoes.)
• injuries that tear or puncture the skin

Diagnosis

A physician who specializes in the treatment of the foot (podiatrist) or the doctor who normally treats the patient's diabetes will treat the infection. An x ray of the foot will be taken to determine whether the bone has become infected. A sample from the wound will be cultured to identify the organism that is causing the infection so that the appropriate antibiotic can be selected.

Treatment

From the results of the culture, the appropriate antibiotic will be prescribed. Any dead or infected tissue will be surgically removed and, if necessary, a cast and/or special shoes may be used to protect the area. In addition, the patient will be instructed to keep off their feet. If the ulcer does not heal, the physician may perform surgery to increase blood flow to the foot. It is also important for the patient to practice good diabetes control and keep blood glucose levels from getting too high.

Alternative treatment

Acupuncture and vitamin C can boost the body's infection-fighting ability. A variety of other vitamins and herbs may improve general health and diabetes control. Because diabetes is a potentially deadly disease, it can be dangerous to try alternative approaches without a doctor's approval or without consulting a trained practitioner of alternative medicine.

Prognosis

Without proper treatment, diabetic foot infections can lead to serious illness, gangrene, amputation, and even death if the infection spreads throughout the body. If treated properly and the patient practices good foot care, the prognosis is generally optimistic.

Prevention

There are many things that a diabetic individual can do to prevent the occurrence of foot infections, including the following:

• control blood glucose and do not allow it to get too high
• avoid smoking
• keep blood pressure and cholesterol under control
• exercise to stimulate blood flow
• keep feet clean, dry, and warm
• check your feet every day for blisters, scratches, and skin that is hard, broken, inflamed, or feels hot or cold when touched
• after bathing, carefully dry feet and apply thin coat of petroleum jelly or hand cream to prevent dry skin from cracking
• use a pumice stone and emery board to trim calluses
• do not neglect an ulcer, should one develop

Resources

ORGANIZATIONS

American Diabetes Association. 1701 North Beauregard Street, Alexandria, VA 22311. (800) 342-2383. 〈http://www.diabetes.org〉.

Juvenile Diabetes Foundation. 120 Wall St., 19th Floor, New York, NY 10005. (800) 533-2873. 〈http://www.jdf.org〉.

National Diabetes Information Clearinghouse. 1 Information Way, Bethesda, MD 20892-3560. (800) 860-8747. 〈http://www.niddk.nih.gov/health/diabetes/ndic.htm〉.

KEY TERMS

Fissure— A deep crack.

Neuropathy— An abnormality of the nerves outside the brain and spinal cord.

Ulcer— A sore or lesion.