Lars Koschorrek, Doctor
What are leg ulcers?
Leg ulcers (Ulcus cruris) are poorly healing (chronic), deep wounds on the lower legs and feet.
Colloquially they are often referred to as open legs. In about 80 percent of cases, they are caused by disturbances in the venous blood circulation, especially varicose veins. These wounds are rarely caused by narrowing of the leg arteries (PAOD).
In Germany, more than one million people suffer from ulcus cruris. The trend is rising.

How do leg ulcers develop?
Venous disorders
Venous leg ulcers, i.e. those caused by venous disorders, account for about 80 percent of all leg ulcers. Leg ulcers are the result of chronic venous insufficiency. The disposition to venous insufficiency is often inherited. The veins expand and lengthen and form varicose veins. This widening causes the valves of the venous system to no longer function properly (close). As a result, blood can flow back and accumulate in the veins. This congestion leads to oedema (accumulation of water in the tissue) and, after a longer period of time, to hardening of the connective tissue (sclerosis). Both changes lead to an insufficient supply of blood and nutrients to the tissue, especially in the area of the inside of the ankles and on the front of the lower leg. This can later lead to leg ulcers.
Blood clots in the deep leg and pelvic veins (thrombosis) are another cause of chronic venous insufficiency. The dilatation of the veins is also called postthrombotic syndrome.

Arterial disorders
More rarely, leg ulcers develop due to disturbances in the arterial blood circulation. The arteries transport the blood from the heart to the tissues of the body to supply them with oxygen and nutrients. If blood circulation is considerably weakened, e.g. due to severe arteriosclerosis, leg ulcers can develop.
Risk factors for arterial leg ulcers are arteriosclerosis of the legs, e.g. due to

Diabetes:
Diabetics may develop diabetic leg ulcers. These leg ulcers are often infected.
Smoking
Elevated blood pressure (hypertension)
High blood lipid levels (hyperlipidemia)
How do you notice leg ulcers?
Venous leg ulcers
mostly occur in the ankle area, especially on the inside of the leg
are often moist and weeping wounds, which often become infected with bacteria and then smell rotten.
usually cause a feeling of tension and no pain
often develop on the basis of a swollen and chronically inflamed leg (stasis eczema). The emigration of red blood cells and deposition of their degradation products (hemosiderin) causes the skin to turn brownish.
Arterial leg ulcers
mostly occur on feet, toes and heels
go along with cold and pale feet and legs
are usually painful, especially during physical exercise and elevation of the leg
How are leg ulcers diagnosed?
It is not difficult for the doctor to diagnose a leg ulcer. However, it is important for the therapy to know the triggering cause.
As a rule, a thorough examination (inspection) of the ulcer and an inquiry of the medical history (anamnesis) is sufficient for the experienced physician to assess the cause of a leg ulcer.
Doppler sonography can be used to visualise both venous and arterial blood circulation conditions. A contrast medium X-ray examination of the veins (phlebography) reveals any blood clots (thromboses). A blood test reveals a possible diabetes or coagulation disorder. In rare cases, a spinalioma (a form of skin cancer) can be the cause of a leg ulcer. This can be ruled out with the help of a tissue sample (biopsy).

How can leg ulcers be treated?
Venous leg ulcers
Compressing bandages:
Consistent implementation of this treatment is the most important measure. Many venous leg ulcers heal under a correctly performed compression measure!
Cleaning of the ulcer:
This is done either fibrinolytically, i.e. with certain ointments that can dissolve firmly adhering coatings. Another method is to remove the deposits with a sharp spoon (curetage).
Envelopes with antiseptic agents, i.e. substances that make the wound sterile or, in the case of heavily weeping wounds, moist envelopes with saline solution.
Antibiotics for massive bacterial colonisation, also in the form of infusions
In the case of varicose veins leading to the ulcer, surgical removal or sclerosing therapy (obliteration) of these varicose veins is helpful.
Frequently, allergic contact dermatitis is also present. Many ulcers are pre-treated with various ointments to which the body can react allergically over time. In these cases a local cortisone therapy can be useful.
A somewhat unappetising, but very effective treatment is a so-called bioenzymatic wound cleansing with fly larvae. Here, 100 to 200 fly larvae are applied to the ulcer for two to three days. During this time, the larvae feed on dead tissue that they have previously accumulated through their saliva. Living tissue is not attacked by the larvae.
Arterial leg ulcers
In the case of arterial leg ulcers, surgical treatment in the form of bypass surgery may be appropriate. A bypass is the bridging of a constricted or closed vascular section with the help of an artery or vein. Some ulcers can be healed more quickly by surgical skin transplantation.
However, the primary goal of ulcer treatment must be to eliminate all factors that have caused the ulcer to develop and hinder healing.

What can they do for themselves?
Venous leg ulcers
Wear fitted compression stockings. Compression is the most important measure!
Walk and move regularly to activate the calf muscles.
If you do not sit with your legs crossed, this will inhibit the vein pump.
When sitting or standing, make sure that you regularly change your working posture and move.
Whenever you have the opportunity, sit with your legs supported (above heart level).
Take them off when they are overweight.
Arterial leg ulcers
Stop smoking!
This is the most important measure. According to the motto: Stop smoking, keep walking!
Move even when you are sitting. First make circular movements with your feet and move your heels up and down. If you move until pain occurs, then take a break. Do not continue with training until you are free of pain again.
Lose weight if you are overweight.
Eat less fat and more fruit and vegetables.
Check your feet and lower legs regularly for colour changes and wounds. This is especially true for diabetics.
Do not wear shoes that are too small or too big. Buy shoes in which your feet feel comfortable.
When taking care of your feet (nail cutting), make sure you avoid any injuries, no matter how minor.
What is the prognosis?
With the right treatment, leg ulcers usually heal within a few months.
Unfortunately, many older patients are exposed to several risk factors. In this age group, the healing of a leg ulcer can take several years.
Venous leg ulcers heal better than arterial ulcers. They are almost never threatened by amputation. However, every second healed ulcer reappears within a year. This rate can be improved by consistent follow-up treatment, especially compression therapy.
Arterial leg ulcers and "shop window disease" (Claudicatio intermittens) are very serious danger signals, which without treatment can lead to a black burn (tissue destruction) and thus to amputation of toes, feet and later legs. The risk of amputation increases with the extent of arteriosclerosis of the leg or pelvic arteries and with the number and severity of the above risk factors. Patients with poorly controlled blood sugar and high blood pressure who also smoke are more likely to have an amputation.

Sources
Guidelines of the German Society of Phlebology
Braun-Falco: Dermatology and Venerology
Herold: Internal Medicine
editorial office
Dr. med. Katharina Larisch