Lymphedema is the accumulation of lymph in tissues, resulting in swelling.
When lymphatic vessels are injured or obstructed (blocked), lymph fluid cannot drain and accumulates in tissues, causing swelling.
Compression bandages or pneumatic stockings can reduce the swelling.
The lymphatic system is one of the body's defense mechanisms against the spread of infection and cancer. Lymph is clear fluid that is made up of water, white blood cells, proteins, and fats that have filtered out of blood vessels into the spaces between cells. Some of the fluid is reabsorbed by the blood vessels, but the rest enters the lymphatic vessels. Lymph then passes through the lymph nodes, which are tiny, bean-shaped organs that filter lymph fluid and act as collection points where damaged cells, infectious organisms, and cancer cells are filtered from the fluid and destroyed. Lymph nodes are located throughout the body, but particular collections are found just under the skin in the neck, under the arms, and in the groin area. If many infectious organisms or cancer cells are present, the lymph nodes swell. Sometimes, organisms cause infection within a lymph node.
Causes of lymphedema
Lymphedema results when the lymphatic system cannot adequately drain lymph from the tissues, causing swelling. Lymphedema is classified as:
Primary lymphedema: Caused by underdevelopment of the lymphatic system
Secondary lymphedema: Caused by a blockage of the lymphatic system
Primary lymphedema
Primary lymphedema results from having so few lymphatic vessels (or lymphatic vessels that are too small, or have never formed at all) that they cannot handle all the lymph. The problem almost always affects the legs. Rarely, however, it does affect the arms.
Several inherited disorders may cause primary lymphedema. These disorders differ according to the age at which swelling becomes obvious.
Rarely, the swelling is obvious at birth, but usually, the lymphatic vessels can handle the small amount of lymph produced in an infant. More often, the swelling appears later in life, as the volume of lymph increases and overwhelms the small number of lymph vessels.
The swelling starts gradually in one or both legs. The first sign of lymphedema may be puffiness of the foot, making the shoe feel tight at the end of the day. The shoe may leave indentations in the skin of the foot. (Many people who experience swelling after they stand for prolonged periods have venous insufficiency due to weak or damaged valves in their leg veins rather than lymphedema. They may have indentations around their ankles after they wear ankle socks, but the indentations are much less deep than those of lymphedema, and the surrounding area is not puffy.)
In the early stages of primary lymphedema, the swelling goes away when the leg is elevated. This disorder worsens with time. The swelling becomes more obvious and does not disappear completely, even after a night’s rest.
Primary Lymphedemas
Disorder | Age at Symptom Onset | Comments |
|---|---|---|
Congenital lymphedema | Before age 2 years | In Milroy disease, a subtype, the toenails are often abnormal. Male infants may have swelling in the scrotum, called a hydrocele. Sometimes diarrhea and jaundice (yellowing of the skin and whites of the eyes) occur. |
Lymphedema praecox | 2–35 years | Also called Meige disease. Typically occurs in females at the onset of menses. Usually the swelling is painless and can affect one or both legs. |
Lymphedema tarda | After age 35 years | Some (but not all) affected people may have family members with this disorder. |
Secondary lymphedema
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Secondary lymphedema is much more common than primary lymphedema, accounting for the overwhelming majority of cases. It typically occurs after major surgical treatment, especially after cancer treatment in which lymph nodes and lymphatic vessels are removed or treated with radiation therapy. For example, the arm tends to swell after removal of lymph nodes in the armpit, most often as treatment for breast cancer.
Scarring of lymphatic vessels as a result of repeated infection also may cause secondary lymphedema, but this type of scarring is very uncommon except among people who have an infection due to the tropical parasite Filaria (filariasis).
In lymphedema, the skin initially looks healthy but is puffy or swollen, and when the area is pressed with a finger, a temporary indentation is left. However, as lymphedema becomes more severe, the skin thickens and may change color and appear dimpled, like orange peel. Once the skin changes occur, pressing the area with a finger does not leave a significant indentation, as it does when edema results from inadequate blood flow in the veins. Rarely, especially in filariasis, the swollen limb becomes extremely large and the skin is so thick and ridged that it looks almost like elephant skin. This disorder is called elephantiasis.
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Complications
Lymphangitis may develop when fungal infections that cause cracks in the skin between the toes or cuts to the hand allow bacteria to enter the skin. The affected limb becomes red (possibly only dark on patients with dark skin) and feels hot. Red streaks may extend toward the trunk from the point of entry, and lymphadenopathy (swollen lymph nodes) may develop. Infrequently, the skin breaks down, which may lead to local infection.
Rarely, long-standing lymphedema leads to a type of cancer called lymphangiosarcoma (Stewart-Treves syndrome), usually in people who have had a mastectomy or other cancer surgeries and radiation therapy, and occasionally in people with filariasis.
Diagnosis of Lymphedema
A doctor's evaluation
Ultrasound
Sometimes other imaging tests (CT, MRI, or lymphoscintigraphy)
The diagnosis of lymphedema is usually based on the person's symptoms and a doctor's examination.
Often ultrasound examination is used to determine whether a blood clot (deep vein thrombosis) is the cause of the swelling.
Sometimes an imaging test such as computed tomography (CT) or magnetic resonance imaging (MRI) is needed to determine the location of a blockage. The lymphatic vessels themselves can be examined, either using specialized MRI scans with contrast (magnetic resonance lymphangiography) or using radioactive isotopes that travel through lymphatic vessels and can be detected by a scan (lymphoscintigraphy).
In areas where filariasis is prevalent, tests for the parasite may be needed.
Treatment of Lymphedema
Relieving fluid build-up
Sometimes, surgery
Lymphedema has no cure.
Treatment of lymphedema typically involves measures to relieve the lymph fluid build-up in a limb. These may include:
Manual lymphatic drainage
Compression bandages or stockings, or intermittent pneumatic compression stockings or sleeves
Limb exercises
For people with lymphedema, manual lymphatic drainage can be helpful. The limb is elevated and manually massaged to drain fluid out of the affected limb. Special limb exercises and compression stockings applied to the legs or sleeves applied to the arms can also reduce the swelling.
People who are more severely affected may wear intermittent pneumatic compression stockings every day for several hours, depending on the extent of symptoms, to reduce the swelling. Once the swelling has been reduced, the person must wear graduated elastic stockings up to the knee or thigh every day from the moment of rising until bedtime. These stockings apply pressure at the ankle and less pressure farther up the leg. This measure controls the swelling to some degree.
For lymphedema in the arm, pneumatic sleeves—like pneumatic stockings—can be used every day to reduce the swelling. Elastic sleeves are also available.
The combination of manual lymphatic drainage, compression stockings/sleeves or devices, exercises, and skin care is called complex (or complete) decongestive therapy.
Primary and secondary lymphedema are sometimes treated with surgery to remove the swollen tissues under the skin and to form new lymphatic drainage channels.
People who have lymphedema may be able to prevent worsening symptoms by avoiding heat, vigorous exercise, and tight garments on the affected arm or leg. Skin and nail care require meticulous attention to avoid infection. Doctors try to avoid doing medical procedures, such as vaccination, drawing blood, taking blood pressure, and inserting intravenous devices, in the affected arm.
People who have had surgery for breast cancer are monitored for the development of lymphedema of the arm.
