Gangrene of the skin is associated with the loss of blood supply of a particular area. In some instances, it is caused by bacterial infection of an open sore or ulceration. The most common form of gangrene develops in the feet of people with diabetes who also have associated loss of circulation in the feet and toes. Any person with poor circulation can develop gangrene. A sudden onset of pain in the feet or legs associated with a decrease in skin temperature, and color changes to the skin of the feet is a strong indication that there has been a sudden blockage of blood flow to the legs. This condition needs immediate medical attention. People who have diabetes may not experience pain associated with such an event because of a condition called diabetic neuropathy. Diabetic neuropathy affects the nerves of the feet and legs causing a diminished ability to perceive pain, excessive heat, cold, vibration, or excessive pressure. This condition places people who have diabetes at greater risk of injury from any source without their being aware of it. For instance, a patient with diabetes can develop an ingrown toenail, and if they also have diabetic neuropathy, they may not experience the same level of pain as someone without the neuropathy. As a consequence the ingrown toenail can worsen, and become infected without providing the warning signs of pain. If the person with diabetes also has poor circulation, the infection can lead to gangrene of the toe. This situation can ultimately lead to the amputation of the toe, foot, or leg, depending upon how bad the circulation is in the leg.
Treatment consists of surgical removal of the gangrene, surgery to improve the circulation (by-pass surgery), hyperbaric oxygen treatment and IV antibiotics.
Severe infections can also cause gangrene. The flesh-eating bacterium called Hemolytic Streptococcus is a rapidly spreading infection. Intense local heat, redness, swelling, fever, and weakness characterize this rapidly developing infection. The infection can start with a small abrasion or injury. This condition requires immediate medical treatment. It can result in amputation and/or death. Treatment consists of surgical removal of the infected tissue and IV antibiotics and supportive care as needed for any failing body functions.