What is lymphedema?

Lymphedema is a condition characterized by swelling in one or more extremities that results from impaired flow of the lymphatic system.

The lymphatic system is a network of specialized vessels (lymph vessels) throughout the body whose purpose is to collect excess lymph fluid with proteins, lipids, and waste products from the tissues. This fluid is then carried to the lymph nodes, which filter waste products and contain infection-fighting cells called lymphocytes. The excess fluid in the lymph vessels is eventually returned to the bloodstream. When the lymph vessels are blocked or unable to carry lymph fluid away from the tissues, localized swelling (lymphedema) is the result.

Lymphedema most often affects a single arm or leg, but in uncommon situations both limbs are affected.

• Primary lymphedema is the result of a design flaw of the lymph vessels and is a rare, inherited condition.
  
  
• Secondary lymphedema results from an identifiable damage to or obstruction of normally-functioning lymph vessels and nodes.
  
  
• Worldwide, lymphedema is most commonly caused by filariasis (a parasitic infection), but in the U.S., lymphedema most commonly occurs in women who have had breast cancer surgery, particularly when followed by radiation treatment.

It has been estimated that worldwide, there are 140-250 million people affected by lymphedema.

What causes lymphedema?

Primary lymphedema causes

Primary lymphedema is an abnormality of an individual's lymphatic system and is likely present at birth, although symptoms may not become apparent until later in life. Depending upon the age at which symptoms develop, three forms of primary lymphedema have been described. Most primary lymphedema occurs without any known family history of the condition.

• Congenital lymphedema is evident at birth, is more common in females, and accounts for 10%-25% of all cases of primary lymphedema. A subgroup of people with congenital lymphedema has a genetic inheritance (in medical genetics termed "familial sex-linked pattern"), which is termed Milroy disease.
  
  
• Lymphedema praecox is the most common form of primary lymphedema, making up 65%-80% of cases. It is defined as lymphedema that becomes apparent after birth and before age 35 years and symptoms most often develop during puberty. Lymphedema praecox is four times more common in females as in males.
  
  
• Primary lymphedema that becomes evident after 35 years of age is known as Meige disease. It is less common than congenital lymphedema and lymphedema praecox and accounts for 10% of cases of primary lymphedema.

Secondary lymphedema causes

Secondary lymphedema develops when a normally-functioning lymphatic system is blocked or damaged. In the U.S., breast cancer surgery, particularly when combined with radiation treatment, is the most common cause. This results in one-sided (unilateral) lymphedema of the arm. Any type of surgical procedure that requires removal of regional lymph nodes or lymph vessels can potentially cause lymphedema. Surgical procedures that have been associated with lymphedema include vein stripping, lipectomy, burn scar excision, and peripheral vascular surgery.

Damage to lymph node and lymph vessels, leading to lymphedema, can also occur due to trauma, burns, radiation, infections, or compression or invasion of lymph nodes by tumors.

Worldwide, however, filariasis is the most common cause of lymphedema. Filariasis is the direct infestation of lymph nodes by the parasite Wuchereria bancrofti. The disease is spread among persons by mosquitoes, and affects millions of people in the tropics and sub-tropics of Asia, Africa, Western Pacific, and parts of Central and South America. Infestation by the parasite damages the lymph system, leading to swelling in the arms, breasts, legs, and, for men, the genital area. The entire leg, arm, or genital area may swell to several times its normal size. Also, the swelling and the decreased function of the lymph system make it difficult for the body to fight infections. Lymphatic filariasis is a leading cause of permanent disability in the world.

What are the symptoms of lymphedema?

The swelling of lymphedema usually occurs in one or both arms or legs, depending upon the extent and localization of damage. Primary lymphedema can occur on one or both sides of the body as well. Lymphedema may be only mildly apparent or debilitating and severe, as in the case of lymphatic filariasis (see above), in which an extremity may swell to several times its normal size. It may first be noticed by the affected individual as an asymmetry between both arms or legs or difficulty fitting into clothing. If the swelling becomes pronounced, fatigue due to added weight may occur, along with embarrassment and restriction of daily activities.

The long-term accumulation of fluid and proteins in the tissues leads to inflammation and eventual scarring of tissues, leading to a firm, taut swelling that does not retain its displacement when indented with a fingertip (nonpitting edema). The skin in the affected area thickens and may take on a lumpy appearance described as an orange-peel (peau d'orange) effect. The overlying skin can also become scaly and cracked, and secondary bacterial or fungal infections of the skin may develop. Affected areas may feel tender and sore, and loss of mobility or flexibility can occur.

The immune system function is also suppressed in the scarred and swollen areas affected by lymphedema, leading to frequent infections and even a malignant tumor of lymph vessels known as lymphangiosarcoma.

How is lymphedema diagnosed?

A thorough medical history and physical examination are preformed to rule out other causes of limb swelling, such as edema due to congestive heart failure, kidney failure, blood clots, or other conditions. Often, the medical history of surgery or other conditions involving the lymph nodes will point to the cause and establish the diagnosis of lymphedema.

If the cause of swelling is not clear, other tests may be carried out to help determine the cause of limb swelling.

• CT or MRI scans may be useful to help define lymph node architecture or to identify tumors or other abnormalities.
  
  
• Lymphoscintigraphy is a test that involves injecting a tracer dye into lymph vessels and then observing the flow of fluid using imaging technologies. It can illustrate blockages in lymph flow.
  
  
• Doppler ultrasound scans are sound wave tests used to evaluate blood flow, and can help identify blood clot in the veins (deep venous thrombosis) that may be a cause of limb swelling.

What are possible treatments for lymphedema?

There is no cure for lymphedema. Treatments are designed to reduce the swelling and control discomfort and other symptoms.

Compression treatments can help reduce swelling and prevent scarring and other complications. Examples of compression treatments are:

• Elastic sleeves or stockings: These must fit properly and provide gradual compression from the end of the extremity toward the trunk.
  
  
• Bandages: Bandages that are wrapped more tightly around the end of the extremity and wrapped more loosely toward the trunk, to encourage lymph flow out of the extremity toward the center of the body
  
  
• Pneumatic compression devices: These are sleeves or stockings connected to a pump that provides sequential compression from the end of the extremity toward the body. These may be used in the clinic or in the home and are useful in preventing long-term scarring, but they cannot be used in all individuals, such as those with congestive heart failure, deep venous thrombosis, or certain infections.
  
  
• Manual compression: Massage techniques, known as manual lymph drainage, can be useful for some people with lymphedema.
  
  
• Exercises: Exercises that lightly contract and stimulate arm or leg muscles may be prescribed by your doctor or physical therapist to help stimulate lymph flow.

Surgical treatments for lymphedema are used to remove excess fluid and tissue in severe cases, but no surgical treatment is able to cure lymphedema.

Infections of skin and tissues associated with lymphedema must be promptly and effectively treated with appropriate antibiotics to avoid spread to the bloodstream (sepsis). Patients affected by lymphedema must constantly monitor for infection of the affected area. In affected areas of the world, the drug diethylcarbamazine is used to treat filariasis.

What are complications of lymphedema?

As noted before, secondary infections of the skin and underlying tissues can complicate lymphedema. Inflammation of the skin and connective tissues, known as cellulitis, and inflammation of the lymphatic vessels (lymphangitis) are common complications of lymphedema. Deep venous thrombosis (formation of blood clots in the deeper veins) is also a known complication of lymphedema.

Those who have had chronic, long-term lymphedema for more than 10 years have a 10% chance of developing a cancer of the lymphatic vessels known as lymphangiosarcoma. The cancer begins as a reddish or purplish lump visible on the skin and spreads rapidly. This is an aggressive cancer that is treated by amputation of the affected limb. Even with treatment, the prognosis is poor, with less than 10% of patients surviving after 5 years.

Can lymphedema be prevented?

Primary lymphedema cannot be prevented, but measures can be taken to reduce your risk of developing lymphedema if you are at risk for secondary lymphedema, such as after cancer surgery or radiation treatment.

The following steps may help reduce the risk of developing lymphedema in those at risk for secondary lymphedema:

• Keep the affected arm or leg elevated above the level of the heart, when possible.
  
  
• Avoid tight or constricting garments or jewelry (also avoid the use of blood pressure cuffs on an affected arm).
  
  
• Do not apply a heating pad to the affected area or use hot tubs, steam baths, etc..
  
  
• Keep the body adequately hydrated.
  
  
• Avoid heavy lifting and forceful activity with the affected limb; but normal, light activity is encouraged.
  
  
• Do not carry a heavy purse on an affected arm.
  
  
• Practice thorough and careful skin hygiene.
  
  
• Avoid insect bites and sunburns.

What is the outlook (prognosis) for lymphedema?

Lymphedema cannot be cured, but compression treatments and preventive measures for those at risk for secondary lymphedema can help minimize swelling and associated symptoms. As mentioned above, chronic, long-term edema that persists for many years is associated with an increased risk of developing a rare cancer, lymphangiosarcoma.

Where can I get help and support for lymphedema?

Many hospitals and treatment centers have support groups for people dealing with specific chronic conditions. Your health care practitioner may be able to direct you to a local support group for those with lymphedema.

The National Lymphedema Network (NLN) (http://www.lymphnet.org/) is a non-profit organization founded in 1988 to provide education and guidance to lymphedema patients, health care professionals, and the general public by disseminating information on the prevention and management of primary and secondary lymphedema.

Lymphedema At A Glance

• Lymphedema is a condition that results from impaired flow of the lymphatic system.
  
  
• Symptoms of lymphedema include swelling in one or more extremities. The swelling may range from mild to severe and disfiguring.
  
  
• Primary lymphedema is present at birth; secondary lymphedema develops as a result of damage to or dysfunction of the lymphatic system.
  
  
• Breast cancer treatment is the most common cause of lymphedema in the U.S.
  
  
• While there is no cure for lymphedema, compression treatments and physical therapy may help reduce the swelling and discomfort.

REFERENCES:

eMedicine.com. "Lymphedema."


eMedicine.com. "Filariasis."

sourceLast Editorial Review: 1/13/2010 10:35:04 AM

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