Please note: This information was current at the time of publication but now may be out of date. This handout provides a general overview and may not apply to everyone. 

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Am Fam Physician. 2008;78(1):81-82

See related article on diabetic foot infection.

What is a diabetic foot infection?

It is an infection in the skin, muscles, or bones of the foot in people who have diabetes.

What causes it?

Over time, high blood sugar levels cause changes to the skin, nerves, and blood vessels in the feet. If you have damaged nerves, you may lose feeling in your feet and you won't be able to feel small cuts, scrapes, blisters, or even pressure from shoes, which can cause calluses or other problems. These minor problems can turn into open sores (called ulcers) or serious infections. Damage to blood vessels slows blood flow to the foot and slows wound healing. This increases the risk of getting an infection that may require removal of the infected area or amputation of the foot.

How can I tell if I have one?

An ulcer on your foot does not always mean that you have an infection. Infections can cause constant pain, redness around an ulcer, warmth and swelling, pus, or an ulcer that does not heal. You should see your doctor as soon as possible if you have any of these signs.

You should also see your doctor or go to the hospital right away if you have fever or chills, have red streaking or redness spreading out from a wound, or if blood is constantly draining from the wound. These can be signs of a very bad infection.

How is it treated?

Antibiotics are usually used to treat the infection. If you have an infection that has moved into the deeper layers of the foot, such as the muscle or bone, you will be sent to the hospital and given antibiotics through an IV. Any dead or infected tissue will be removed. Some people with poor circulation may need surgery to improve blood flow to the foot and to avoid amputation.

The wound should start to heal in two to three days. Your doctor will check the wound at least once a week to make sure it is healing. You may need a nurse to help you at home with wound care. You may also have to wear a cast or special shoes to protect the wound area. You should stay off your foot as much as possible and keep your foot raised.

How can I prevent it?

  • Control blood sugar levels to prevent damage to blood vessels and nerves.

  • Check your feet, including between your toes, every day for sores and cuts. Tell your doctor right away if you notice a problem.

  • Have your doctor check your feet at least once a year.

  • Keep your feet clean, dry, and warm.

  • Always wear shoes that fit well to avoid rubbing and pressure. Don't go barefoot, even at home, because this increases the risk of injury.

  • Trim your toenails along the shape of the toe and file the nails to remove sharp edges.

  • If you have nerve damage, don't trim toenails yourself. You should see your doctor or a podiatrist (a doctor who specializes in foot care) for even minor foot procedures.

  • Do not smoke.

Where can I get more information?

Your doctor

American Academy of Family Physicians

American Diabetes Association

National Diabetes Information Clearinghouse

American Podiatric Medical Association

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