Pressure ulcers are sores that occur when pressure cuts off the blood supply to the skin. The stress that is caused by the body's weight, and the impact of the foot striking the ground can place the big toe, the heel and the ball of the foot at greatest risk for pressure ulcers. If left untreated, an ulcer may allow infection to enter your body. If the infection reaches the bloodstream or bone, your life or limb may be at risk. With your doctor's help, pressure ulcers can be controlled, healed and even prevented.
How Do They Form?
Pressure or friction against the bottom of your foot causes the skin to thicken, forming a callus. If the skin keeps thickening, the callus presses up into the foot. This kills healthy tissue, and causes pain. Unfortunately, you may not notice the pain if you have a loss of sensation. As healthy skin dies, an ulcer forms. Ulcers may progress from hot spots to infected wounds very quickly.
Red "hot" spots on the skin are signs of pressure or friction. They are a warning that you need to take immediate care of your feet. If pressure is not relieved, a hot spot is likely to blister. Left untreated, a blister can turn into an open wound.
If bacteria enter the ulcer, infection can occur, causing more healthy tissue to die. The infected ulcer may begin to drain with a white, yellow or greenish discharge. Some infected ulcers may bleed or have a bad odor. If you develop any of these signs, it is important to call your physician immediately.
Blood flow and nerve testing may be done if you have a chronic health problem like diabetes. Testing sensations can be as simple as finding out if you can feel a monofilament at certain pressure spots. Testing your blood flow is simple. The most common method used is an ankle-brachial index (ABI). It compares the blood pressure of your arm to that of your leg. This is a non-invasive procedure done with a pressure tourniquet.
With your physician's care, callouses, blisters, small cracks, or sores can be treated before they get infected. To assist healing, thickened skin around the ulcer may be cleaned away. Medicated ointment or cream may be applied to prevent infection. Sometimes a special dressing is used to keep the wound dry. Antibiotics may be prescribed for you if necessary.
Your doctor may recommend orthotic devices to take the pressure off of hot spots and ulcers. These custom-made shoe inserts absorb or divert pressure from problem areas. Special shoes or temporary cast may also be used to redistribute pressure. Your doctor may also recommend that you stay off your foot for a period of time to allow the wound to heal.
Antibiotics may be prescribed to control or prevent infection. It is important to take all of the medication, and to take it exactly as directed. If you stop taking an antibiotic too soon, the infection may return.
Surgery may be needed if the infection enters deep tissues or bone. The physician will clean away the infection, while removing as little tissue or bone as possible. You may also be given intravenous antibiotics to fight the infection.
You may be able to prevent pressure ulcers, or reduce your risk, by taking care of your feet. Check your feet daily. Use a mirror, or ask someone to look at the bottom of your feet. This will help you catch small skin changes before they progress to ulcers. Check the soles and the inside of your shoes for foreign objects before you put them on. Protect your feet by wearing shoes and socks that don't rub. Call your physician if you notice hot spots, red streaks, swelling or any cracks or sores.
Try to improve your overall health by eating right and getting exercise. Also control any health problems such as diabetes or kidney disease that may affect your feet. If you smoke, stop. Smoking reduces blood flow and slows healing, increasing your risk of developing a poor healing wound.
*photo credit: The StayWell Company / Krames Patient Education