A foot ulcer is an open sore on the foot. A foot ulcer can be a shallow red crater that involves only the surface skin. A foot ulcer also can be very deep. A deep foot ulcer may be a crater that extends through the full thickness of the skin. It may involve tendons, bones and other deep structures. People with diabetes and people with poor circulation are more likely to develop foot ulcers.
It can be difficult to heal a foot ulcer. In people with these conditions, even a small foot ulcer can become infected if it does not heal quickly. If an infection occurs in an ulcer and is not treated right away, it can develop into: an abscess (a pocket of pus), a spreading infection of the skin and underlying fat (cellulitis), a bone infection (osteomyelitis) or gangrene which is an area of dead, darkened body tissue caused by poor blood flow. Among people with diabetes, most severe foot infections that ultimately require some part of the toe, foot or lower leg to be amputated start as a foot ulcer.
Foot ulcers are especially common in people who have one or more of the following health problems: Peripheral neuropathy, Circulatory problems, Abnormalities in the bones or muscles of the feet. More than any other group, people with diabetes have a particularly high risk of developing foot ulcers. This is because the long-term complications of diabetes often include neuropathy and circulatory problems. Without prompt and proper treatment a foot ulcer may require hospital treatment. Or, it may lead to deep infection or gangrene and amputation.
A foot ulcer looks like a red crater in the skin. Most foot ulcers are located on the side or bottom of the foot or on the top or tip of a toe. This round crater can be surrounded by a border of thickened, callused skin. This border may develop over time. In very severe ulcers, the red crater may be deep enough to expose tendons or bones. In most cases, your doctor can tell that you have a foot ulcer simply by looking at your foot. In people who have good circulation and good medical care, an ulcer sometimes can heal in as few as three to six weeks. Deeper ulcers may take 12 to 20 weeks. They sometimes require surgery.
People who are at risk of foot ulcers, such as those with diabetes, can take steps to help prevent foot ulcers. They can do this by examining their feet routinely and following good foot-hygiene practices. Examine every part of your feet every day to check for rubbed areas, cracks or calluses. If necessary, use a mirror to check the heel and sole. If your vision is not good, ask a relative or caregiver to examine your foot for you. Practice good foot hygiene. Wash your feet every day using mild soap and warm water. Dry thoroughly, especially between the toes. Apply moisturizing lotion to dry areas, but not between the toes. Wear shoes that fit well and soft, absorbent socks. Always check your shoes for foreign objects and rough areas before you put them on. Change your socks immediately if they become wet or sweaty. If you have corns or calluses, ask your doctor about how to care for them. Your doctor may determine that these problems are best treated in his or her office rather than at home.