Venous skin ulcer: The appearance of a venous leg ulcer looks different than ulcers caused by other problems such as poor circulation or nerve problems. To rule out poor circulation as a cause, it is usual for a doctor or nurse to check the blood pressure in the ankle and in the arm. The ankle blood pressure reading is divided by the arm blood pressure reading to give a blood pressure ratio called the Ankle Brachial Pressure Index (ABPI). If the ratio is low, it indicates that the cause of the ulcer is likely to be poor circulation rather than venous problems. This is very important to know as the treatments are very different. An ABPI may be checked routinely to make sure the circulation to the legs remains adequate.
Routine blood and urine tests may also be done to rule out diseases that may cause or aggravate skin ulcers, such as anemia, diabetes, kidney failure, or arthritis.
Pressure ulcers: Pressure sores (bedsores) are usually unmistakable, even in the initial stages, but a doctor is likely to order blood tests to check the individual's nutritional status and overall health. Other tests may include: urine analysis and culture, stool culture, and a wound biopsy. A wound biopsy is a sample of tissue is taken from wounds that do not heal or from chronic (long-term) pressure sores. The tissue may also be checked for cancer, which is a risk in individuals with chronic wounds.
signs and symptoms
The first sign of a venous skin ulcer is the appearance of dark red or purple skin over the affected area. The skin may also become thickened and dry and itchy. Without treatment, an ulcer may form. The wound may be painful, and the individual may also have swollen and achy legs. Rashes may occur, such as contact dermatitis, on the skin around the ulcer.
Because venous skin ulcers are a result of poor blood circulation, these wounds are often slow to heal. If an ulcer becomes infected, there may be an odor, pus draining from the wound, and increased tenderness and redness.
One or more ulcers may develop on the leg or both legs. The outer layers of skin die and are shed (sloughed), exposing deeper tissues. Spots of white scar tissue may develop in the skin around a venous ulcer.
If venous ulcers result from chronic venous insufficiency, the legs are swollen, and the skin is dark reddish brown and very firm (a condition called stasis dermatitis). The skin may itch, and the ulcers are usually very painful.
Cellulitis, a type of infection of the skin, often develops around a venous ulcer. Typically, the infected skin is red, warm, swollen, and tender. Red streaks occasionally appear. Pus or fluid may leak from the ulcer, especially if infection involves tissues below the skin (such as muscle).
Bedsores fall into one of four stages based on their severity. Pressure sores are categorized by severity, from Stage I (earliest signs) to Stage IV (worst). The National Pressure Ulcer Advisory Panel, a professional organization dedicated to the prevention and treatment of pressure sores, has defined each stage as follows:
Stage I: Initially, a pressure sore appears as a persistent area of red skin that may itch or hurt and feel warm and spongy or firm to the touch. In African Americans, Hispanics, and other people with darker skin, the mark may appear to have a blue or purple cast, or look flaky or ashen. Stage I wounds are superficial and go away shortly after the pressure is relieved.
Stage II: In stage II, some skin loss has already occurred, either in the epidermis, the outermost layer of skin, in the dermis, the skin's deeper layer, or in both. The wound is now an open sore that looks like a blister or an abrasion, and the surrounding tissues may show red or purple discoloration. If treated promptly, stage II sores usually heal fairly quickly.
Stage III: When a pressure ulcer reaches stage III, the damage has extended to the tissue below the skin, creating a deep, crater-like wound.
Stage IV: Stage IV is the most serious and advanced stage. The pressure ulcer has become so deep that there is damage to the muscle and bone, and sometimes tendons and joints. Stage IV wounds are extremely difficult to heal and can lead to lethal infections.
If an individual uses a wheelchair, he/she is most likely to develop a pressure sore on the tailbone or buttocks, the shoulder blades and spine, or the backs of the arms and legs where they rest against the chair. When an individual is bedridden, pressure sores may occur on the back or sides of the head; the rims of the ears; the shoulders or shoulder blades; the hipbones, lower back, or tailbone; or the backs or sides of the knees, heels, ankles, and toes.
Bone and joint infections:
Bone and joint infections
develop when the infection from a bedsore burrows deep into the joints and bones. Joint infections, known as septic or infectious arthritis, can damage cartilage and tissue within days, whereas bone infections (osteomyelitis) may develop over years if not treated. Eventually, bone infections can lead to reduced function and bone death, which may require amputation.
Cellulitis: Cellulitis is a potentially serious bacterial infection of the skin. The most common bacteria that cause cellulitis are Streptococcus pyogenes and Staphylococcus aureus. Cellulitis appears as a swollen, red area of skin that feels hot and tender and it may spread rapidly. Skin on the face or lower legs is most commonly affected by this infection, though cellulitis can occur on any part of the body. Cellulitis may only affect the surface of the skin. However, cellulitis may also affect the tissues underlying the skin and can spread to lymph nodes and the bloodstream. Left untreated, the spreading bacterial infection may rapidly turn into a life-threatening condition.
Necrotizing fasciitis: Necrotizing fasciitis is a rapidly spreading infection that destroys the layers of tissue that surround the muscles. Initial signs and symptoms include fever, pain, and massive swelling. Without treatment, death can occur in as little as 12-24 hours.
Gas gangrene (myonecrosis): Gas gangrene is a
rare and severe form of gangrene. Gas gangrene develops suddenly and dramatically and spreads so rapidly that changes in tissue are noticeable within minutes. The bacteria responsible for gas gangrene (Clostridium sp.) produce toxins that completely destroy affected muscle tissue and cause potentially fatal systemic problems. Amputation of the infected limb may be required.
Sepsis: Sepsis (a blood infection) can occur from a wound such as advanced pressure sores. Sepsis occurs when bacteria from a massive infection enter the bloodstream and spread throughout the body. Sepsis is a rapidly progressing, life-threatening condition that can cause shock and organ failure.
causes and risk factors
Venous (skin) ulcer
Avenous skin ulcer, also called a stasis leg ulcer, is a shallow wound that develops due to venous insufficiency, a condition where the leg veins do not move blood back toward the heart normally. Venous skin ulcers typically develop on either side of the lower leg, between the ankle and calf.
The veins in the body have valves that keep blood flowing toward the heart. In a condition called venous insufficiency, the valves are damaged and allow some blood to back up in the vein. The slowed circulation causes fluid to seep out of the overfilled veins into surrounding tissues, causing tissue breakdown and ulcers.
Less frequently, blocked veins are a contributing factor in the development of venous skin ulcers. Veins can become blocked due to deep vein thrombosis (DVT, or a blood clot in the leg).
Factors that contribute to venous insufficiency and increase the risk of developing venous skin ulcers include: deep vein thrombosis (DVT), which may result from a severe leg injury (such as a broken or crushed bone), or leg surgery (including knee replacement and varicose vein procedures). Deep vein thrombosis may also develop when a person does not move around for long periods (for example, if a person is paralyzed or bedridden) or is obese. DVT may develop during pregnancies, which may aggravate an existing venous problem. People with blood clotting disorders or family histories of varicose veins also have an increased risk of developing DVT.
Pressure (decubitus) ulcers
A pressure (decubitus) ulcer, also known as a bedsore or pressure sore, is an area of skin that breaks down when an individual stays in one position for too long without shifting his/her weight. This often happens if an individual is bed ridden or confined to a wheelchair, even for a short period of time (such as after surgery or an injury). Constant pressure against the skin reduces the blood supply to that area, and the affected tissue eventually dies.
A pressure ulcer starts as reddened skin but gets progressively worse, forming a blister, then an open sore, and finally a deep, circular wound called a crater. The most common places for pressure ulcers are over bony prominences (bones close to the skin) like the elbow, heels, hips, ankles, shoulders, back, and the back of the head. Pressure ulcers occur in approximately 9% of hospitalized patients, usually during the first two weeks of hospitalization, and in approximately 25% of nursing home residents.
Risk factors for developing a pressure ulcer include:
Age: The majority of pressure sores occur in people older than 70. Older adults tend to have thinner skin than younger people do, making them more susceptible to damage from minor pressure. Elderly individuals also tend to be underweight, with less natural cushioning over their bones. And poor nutrition, a serious problem among older adults, not only affects the integrity of the skin and blood vessels but also hinders wound healing. Even with optimum nutrition and good overall health, wounds tend to heal more slowly as individuals age. Also, nursing home residents have higher rates of bedsores than do people who are hospitalized or cared for at home due to immobilization and urinary incontinence.
Conditions affecting circulation:
Because certain health problems such as diabetes and vascular disease affect circulation, parts of the body may not receive adequate blood flow, increasing an individual's risk of tissue damage.
Decreased mental awareness: Individuals whose mental awareness is lessened by disease, trauma, or medications are often less able to take the actions needed to prevent or care for pressure sores. Conditions that impair cognition, such as dementia and Alzheimer's disease, may also lead to decreased mental awareness and an increased need to prevent or care for pressure sores.
Lack of pain perception: Individuals with a loss of sensation, such as patients with spinal cord injuries or diseases, cannot feel discomfort or the need to change positions when a bedsore is forming.
Malnutrition: Individuals are more likely to develop pressure sores if they have poor diets, especially one deficient in protein, zinc, and vitamin C. Individuals that are malnourished are also more likely to have recurrent pressure sores, more severe infections, and slower healing wounds than are people with healthier diets.
Smoking: Smokers have a higher incidence of pressure sores than nonsmokers. Smokers also tend to develop more severe wounds and to heal more slowly, mainly because nicotine impairs circulation and reduces the amount of oxygen in the blood. The risk increases with the number of years and cigarettes smoked.
Urinary or fecal incontinence: Problems with bladder control can greatly increase the risk of pressure sores because the skin stays moist from urine, making it more likely to be damaged. Bacteria from fecal matter not only can cause serious local infections but also lead to life-threatening systemic complications such as sepsis, gangrene, and, rarely, a severe and rapidly spreading infection called necrotizing fasciitis.
Diabetic peripheral neuropathy (nerve damage as a result of diabetes) causes the greatest risk of foot ulceration, due to disease of the microvascular (small blood vessels) and uncontrolled blood sugar levels. Peripheral neuropathy disables sensation in the feet so the individual is unable to sense pain or discomfort if injured in that area. This allows the ulcer to be left untreated, increasing the risk of infection.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDKD), an estimated 18 million Americans (6.3% of the population) are affected with diabetes, and millions more are considered to be at risk. Of those at risk, diabetes is undiagnosed in 5.2 million people. Diabetic foot lesions are responsible for more hospitalizations than any other complication of diabetes. Among patients with diabetes, 15% will develop a foot ulcer, and 12-24% of those with a foot ulcer will require amputation. Diabetic ulcers are the most common foot injuries, accounting for 60% of lower extremity amputations in the United States.