Lymphedema: Interstitial Fluid Buildup

Lymphedema is a condition in which lymphatic fluid builds up in the interstitial space (the space between tissues) of the extremities. Most often, lymphedema causes swelling (edema) in the arms and legs as interstitial fluid accumulates, but swelling can occur anywhere in the body. An estimated 140 to 250 million people internationally live with some degree of lymphedema.

Lymphedema can develop by itself (primary lymphedema) or as a consequence of other conditions (secondary lymphedema). Primary lymphedema may be present from birth, or interstitial fluid buildup may develop during puberty or adulthood. Sixty to eighty percent of primary lymphedema cases are classified as lymphedema praecox (when interstitial fluid buildup begins after birth, but before age 35).

Often, no cause can be found for primary lymphedema. In some cases, fluid buildup can be traced to blood vessel abnormalities such as:

By far the most common cause of lymphedema in the US is surgical removal of part of the lymphatic system. Breast cancer surgery, which often requires the removal of local lymph nodes, is a common cause of secondary lymphedema.

When portions of the lymphatic system are damaged or removed, the system may no longer be able to transport lymphatic fluid as effectively. When this happens, excess lymphatic fluid leaks into interstitial tissues causing swelling.

Interstitial fluid buildup resulting from surgery is not always immediately apparent. Lymphedema can occur months, or even years, after a surgical event or trauma.

Secondary lymphedema can result as a complication of chemotherapy or radiation therapy. The chemotherapeutic drug tamoxifen can cause lymphedema in the legs.

Physical trauma, burns, burn excisions and even insect bites have been known to cause lymphedema. Internationally, the most common cause of secondary lymphedema is filariasis. Filariasis is an infection of the lymph nodes by the parasites Wuchereia bancrofti and Brugia malayi.

 

Lymphedema may be temporary, in which case symptoms resolve themselves after six months, and no hardening of the affected tissue occurs. Chronic lymphedema is an irreversible, lifelong condition that progresses through three distinct stages:

 

Swelling due to interstitial fluid buildup is the most obvious lymphedema symptom. Lymphedema can also cause:

No cure for chronic lymphedema exists. Chronic lymphedema treatment centers on relieving symptoms, monitoring interstitial fluid buildup for signs of infection and draining fluid buildup. Taken as a whole, the treatments are known as CDT (complex decongestant therapy).

Vigilant skin hygiene is essential to remove scales caused by lymphedema and to keep skin cracks clean. Good hygiene reduces the risk of skin and interstitial fluid infection. Care must be taken to avoid even small injuries in order to avoid infection. Losing weight can help to slow progression.

Loose-fitting clothing should be worn. At night, elevating affected limbs may provide some relief from swelling. Doctors may also suggest bandaging the limb, or wearing special compression garments.

Medical staff (and in some instances the patient) may manually drain interstitial fluid buildup to relieve symptoms and slow progression. Lymphedema drainage must be halted at the first sign of lymphangitis, however, and not resumed until the infection is cured. Drainage should also be ceased immediately if cancer is suspected.

Diuretics, which flush fluids out of the body, may seem to be a likely treatment for lymphedema. In fact, diuretics do nothing to reduce interstitial fluid buildup, and can actually make lymphedema worse.

Even with careful monitoring of lymphedema symptoms and treatment, complications are common, particularly lymphangitis. The stagnant, protein-rich interstitial fluid provides a potential breeding ground for bacteria.

Symptoms of lymphangitis include:

Chronic lymphedema results in a gradual hardening of affected tissue, and an increase in the size of the affected limb. These two complications cause a slow loss of limb function. Embarrassment about the appearance of swollen limbs can severely limit social interactions.

Severe cases of lymphedema can progress into a rare form of cancer called lymphangiosarcoma, a cancer that affects about ten percent of chronic lymphedema patients after ten years. The cancer causes reddish purple skin nodules that spread quickly. Often requiring limb amputation, lymphangiosarcoma has a poor prognosis, with a five-year survival rate of less than ten percent.

Resources

National Cancer Institute. (updated 2004). Lymphedema (PDQ).

National Lymphedema Network. (nd). Lymphedema: A brief overview.

Revis, D. (updated 2002). Lymphedema.

Society for Vascular Surgery. (updated 2004). Lymphedema.

World Health Organization. (2000). Lymphatic filariasis [Fact Sheet N°102].