What is an open leg?
An open leg is a poorly healing wound (formerly known as an ulcer) on the lower leg or foot. In medical terms, it is also known as a leg ulcer or simply an ulcer. Like pressure ulcers (decubitus ulcers) and diabetic foot ulcers (malum perforans), it is a chronic wound. Their hallmark is that they have been present for at least four weeks and there are no signs of healing despite correct wound treatment. Normally, a wound that is not surgically stitched is on its way to spontaneous healing within two to three weeks.
An open leg is most frequently the result of circulatory disorders of the veins and/or arteries. There are various diseases that are associated with reduced blood flow – and therefore poor oxygen and nutrient supply to tissues. Examples include chronic venous disease as a result of deep vein thrombosis in the legs or untreated varicose veins, or peripheral arterial occlusive disease (PAD). PAD is favored by cardiovascular risk factors (these are: Smoking,diabetes, lipometabolic disorders and high blood pressure).
The treatment of an open leg depends largely on the cause. It must not be limited to the selection of the optimal dressing. The triggering causes must be clarified and treated. Otherwise the open leg will always return. There are various treatment options that promote wound healing and allow the leg ulcer to heal.
Open leg – frequency and age
Chronic wounds on the lower leg and foot are relatively common. Large-scale studies have shown that around one percent of the population will develop an open leg in the course of their lives. The risk of ulcers increases with age because certain diseases of the arteries and veins occur more frequently. The risk of an open leg after the age of 80 is four percent.
Open leg: causes and risk factors
An open leg can have one or more different causes. As a rule, circulatory disorders of the veins and/or arteries are involved. Experts distinguish between different forms of leg ulcers depending on the trigger.
Venous leg ulcer (venous leg ulcer, venous ulcer)
The cause of venous leg ulcers is chronic venous insufficiency. In medical terms, it is also known as chronic venous disease (CVD), or formerly chronic venous insufficiency (CVI). This affects the veins, which are supposed to transport blood back from the legs and up to the heart. If the venous outflow backs up, the pressure on the tissue and the small blood vessels increases. The skin on the lower legs becomes hard and less well supplied with blood – this can lead to an open leg. Around 50 percent of lower leg ulcers are due to CVC. Around half of these cases are due to a deep vein thrombosis suffered in the past and the other half are due to varicose veins.
Arterial-induced leg ulcer (arterial leg ulcer, arterial ulcer)
In this case, arteriosclerosis of the legs (PAD, see above) is to blame for the leg ulcer. As a result of years of untreated cardiovascular risk factors (see above), the arteries that transport blood and oxygen from the heart to the organs and legs become narrower and narrower on the inside. Some of those affected feel the lack of oxygen as foot, calf or thigh pain when walking and therefore always have to stop (PAD). However, some immediately develop pain in the foot and toes when lying down, which only subsides when the foot is lowered, or chronic wounds on the lower leg or foot (ulcus cruris arteriosum). Around ten percent of all patients with a leg ulcer suffer from an arterial ulcer.
Ulcus cruris mixtum (mixed venous-arterial ulcer): Venous ulcer and PAVK
Mixed venous-arterial ulcers account for around 20 percent of all chronic wounds on the lower leg. This is a venous ulcer (see above) in a leg that also suffers from PAD (see above). The treatment must (A) PAVK and (B) consider chronic venous disease as a cause.
Open leg with causes other than chronic venous disease and/or PAD
Around 20 percent of leg ulcers are due to another cause (i.e. no chronic venous disease and/or no PAD).
Other causes of leg ulcers:
- Severe skin infections, more frequent in cases of malnutrition (e.g. alcoholism or social isolation in old age): Malnourished patients in particular, but also patients who have to take immunosuppressive medication as a result of a kidney transplant, for example, are at risk of aggressive skin infections, which often start from an inflamed hair follicle or a minor wound and then spread like wildfire through the skin (erysipelas) and can lead to extensive infectious wounds (ecthyma).
- Abrasion of very thin areas of skin (lacerations) and extensive bruising on very thin skin: Older people can develop very thin skin, especially on the arms and legs (atrophy of the skin, dermatoporosis). They are endangered by the abrasion of large skin triangles or the formation of pronounced bruising (the latter especially in the case of blood thinning) in the event of minor impact or hooking.
- Severe inflammatory skin diseases: The prototype is the so-called pyoderma gangraenosum, in which the white blood cells of the neutrophil granulocyte type are overactive. Typically, minor skin injuries result in large superficial wounds with a pus rim, which quickly eat into the healthy surrounding skin. The pus does not contain bacteria, but is the result of an excessive immune response. Those affected are also prone to intestinal inflammation (ulcerative colitis, Crohn’s disease) or joint inflammation (rheumatoid arthritis).
- Severe vascular inflammation due to a misdirected immune response (vasculitis with skin damage): Also rather rare, severe inflammatory processes in the smaller blood vessels of the skin (vasculitis) can result in circulatory disorders and oxygen deficiency in the affected area, which can lead to large, deep skin wounds that heal very poorly.
- Malignant skin tumors: A small fraction, perhaps two percent, of all chronic wounds on the lower leg develop as a result of an undetected skin cancer, e.g. spinocellular carcinoma or basal cell carcinoma (two types of white skin cancer).
Symptoms: Open leg causes a wide range of symptoms
The symptoms of an open leg depend on the underlying cause of the wound – venous, arterial, a combination of both, or other factors.
Venous ulcer (Ulcus cruris venosum)- Symptoms
Typically, the venous ulcer occurs on the inside of the lower leg, within an area of brown discolored skin above the inner ankle. The following symptoms indicate chronic venous disease, from which a venous ulcer can develop:
- Swelling of the lower leg and ankles
- Pronounced varicose veins
- Skin inflammation with scaling, and especially brown, hard skin on the inside of the lower third of the lower leg
Arterial ulcer (ulcus cruris arteriosum) – symptoms
The arterial ulcer is more frequently located above the lateral malleolus or at the edge of the tibia. It is usually very painful. However, advanced PAD (see above) can also cause poorly healing wounds on the back of the foot and on the toes. Pain in the legs – first during movement and physical exertion, later also at rest; the pain intensifies when you elevate your legs (in contrast to venous leg ulcers)
- Sometimes those affected experience pain in the foot, calf or thigh before or at the same time as walking, as an expression of the lack of oxygen to the muscles under strain.
- Wounds caused by arteries are often black in the center or at the edge (necrosis)
Mixed venous-arterial ulcer (ulcus cruris mixtum) – symptoms
Patients with a mixed veno-arterial ulcer have the same symptoms as those with a venous ulcer.
Diagnosis of an open leg
The ABCDE rule proposed by the Initiative for Chronic Wounds (ICW) can be helpful in diagnosing an open leg. The letters ABDCE stand for the following:
A: Anamnesis (medical history)
When an open leg is diagnosed, you will be asked a few questions about your medical history. This is because, as a rule, if a wound no longer closes, the cause lies in another illness. The following questions, for example, are of interest to us:
- What symptoms have you noticed?
- How severe are the symptoms?
- Are there situations in which the symptoms get worse or better?
- How long has the open wound existed?
- Have you suffered from wounds in the past that were difficult to heal?
- Do you suffer from vein disease? Have you suffered a deep vein thrombosis or pulmonary embolism in the past? Do you have large varicose veins (varicose veins) or have you had varicose veins removed?
- Are you known to suffer from PAD? Have you already had a procedure with a balloon catheter or a bypass operation on your leg?
- What underlying illnesses do you have? Do you suffer from high blood pressure or diabetes? Do you smoke? Do you have a known high blood lipid level? Do you have heart disease, lung disease, kidney disease or other significant diagnoses?
- How tall and how heavy are you?
- Are you taking any medications? If yes: Which and since when?
Based on your answers, an initial assessment of the possible causes of the leg ulcer can be made and further examinations can be ordered.
B: Bacteria
If a bacterial wound is suspected or a wound colonization with antibiotic-resistant bacteria needs to be investigated, the treatment team takes a swab and has it examined in the laboratory.
C: Clinical examination
We assess the wound according to the following criteria:
- Where exactly is it located on the lower leg / foot?
- How large and deep is it, and what is the predominant color?
- What do the wound edge and the surrounding skin look like?
- Does it give off a noticeable odor?
- Is the wound oozing and secreting fluid? If so, what is the nature of this?
- Does it cause pain, spontaneously or when touched?
Based on the appearance of the wound, initial decisions can be made regarding further clarification and treatment.
D: Circulation
The treatment team examines the veins and arteries to obtain information about the blood circulation in the entire leg and in the area of the wound. The veins are examined in particular using color-coded ultrasound (duplex ultrasound). The arteries are first examined using a blood pressure cuff on the ankle and a small Doppler ultrasound probe. If necessary, this is followed by pressure-wave drainage with cuffs (oscillography), also a duplex ultrasound examination, and finally angiography using X-rays.
Open leg: prevention, early detection, prognosis
The reasons for an open leg often lie in circulatory disorders. The veins, arteries or both types of vessels are affected. Some risk factors are known which favor venous or arterial diseases. And you can tackle these yourself – sometimes they lie in your lifestyle – and thus prevent leg ulcers. Examples are sufficient exercise, a healthy diet, a normal weight or not smoking.
In addition, have existing illnesses such as high blood pressure, diabetes mellitus or lipometabolic disorders adequately treated by a doctor. A healthy lifestyle also has a positive effect on these diseases.
As a general rule, always consult your doctor promptly if you have any complaints. This allows underlying diseases such as varicose veins, venous insufficiency or peripheral arterial occlusive disease to be detected at an early stage. Then have the disease monitored at regular check-ups. An open leg can also be diagnosed and treated in good time.
Course and prognosis of the open leg
The course and prognosis depend on the cause, but also on the severity and extent of the leg ulcer. In addition, the open leg, but above all the causes of the ulcer, must be treated consistently. You yourself must also participate well in the therapy.
In most cases, an open leg takes around three to six months to heal – sometimes even longer. Relapses are also not uncommon. Depending on the severity, around 10 to 30 percent of those affected with a venous ulcer have a relapse after one year. Patients with combined arterial and venous circulatory disorders are also susceptible to the recurrence of open legs. If you consistently wear compression stockings during the day, you can effectively prevent such relapses.