A diabetic foot ulcer is an open sore or wound that forms on the foot of an individual with diabetes. These ulcers are a serious complication of diabetes, arising from nerve damage, poor circulation, and foot deformities. The breakdown of skin tissue exposes underlying layers, creating a wound that can be slow to heal.
Where Diabetic Foot Ulcers Appear and Their Initial Signs
Diabetic foot ulcers most commonly appear on the bottom of the foot, particularly under the big toes and the balls of the feet, due to pressure points. They can also develop on the heels or other areas subject to repeated irritation, such as from poorly fitting shoes. Regular foot inspection is important for individuals with diabetes.
The earliest signs of a developing ulcer can be subtle. Initial signs include unusual redness or swelling in a localized area. The skin in the affected region may also feel warmer. Sometimes, a callus or thickened skin may form, and an ulcer can develop underneath it.
A small break in the skin, a blister, or a scratch that does not heal promptly can also indicate an impending ulcer. Since nerve damage (neuropathy) often reduces sensation in the feet, these early signs might not be accompanied by pain, making regular foot checks even more important for early detection.
How Developed Ulcers Appear
Once a diabetic foot ulcer has developed, its appearance can vary depending on its severity. The wound often looks like a round, red crater in the skin. The edges may be well-defined or irregular, and the surrounding skin can appear thickened and calloused. Ulcers can be superficial, involving only the full thickness of the skin, or deep, potentially exposing underlying tendons, ligaments, muscles, or even bones and joints.
The wound bed’s color can range from red, indicating healthy granulation tissue, to yellow, suggesting the presence of slough (dead tissue). Black tissue, known as eschar, often surrounds the ulcer due to a lack of healthy blood flow to the area.
Discharge is also common. This exudate can vary in color, appearing clear, yellow, or green, and may have an unpleasant odor, particularly if an infection is present. Drainage on socks or in shoes can be one of the first noticeable signs of an ulcer.
Other Signs and Potential Outcomes
Beyond the visible wound, other signs can accompany a diabetic foot ulcer. The area around the ulcer may show increased warmth or swelling. If an infection is present, additional redness may extend beyond the wound, and a fever or chills could develop. A foul, pungent odor from the foot also indicates infection.
Untreated diabetic foot ulcers can lead to serious complications. Infections can spread from the ulcer to surrounding tissues (cellulitis) or even to the bone (osteomyelitis). In severe cases, poor blood flow combined with infection can lead to gangrene, which is tissue death. This progression increases the risk of lower extremity amputation.
What to Do If You Suspect an Ulcer
If a diabetic foot ulcer is suspected, prompt medical attention is recommended. Contact a healthcare professional, such as a doctor or podiatrist, immediately. Early intervention is important for effective treatment and to prevent worsening.
Do not attempt to treat the ulcer at home with over-the-counter remedies. Keeping the area clean and avoiding any pressure on the suspected ulcer or wound is important until a medical professional can evaluate it. They can diagnose the ulcer, assess its severity, and initiate a treatment plan to promote healing and prevent further complications.