The most common cause of secondary, or acquired, lymphedema worldwide is due to lymphatic disruption and obstruction by infection with the nematode Wuchereria bancrofti, also known as filariasis (see Chapter 207). In the industrialized world, the most common cause is malignancy and malignancy-associated therapeutic interventions, such as surgery and radiotherapy.17
Chronic edema in a community sample in London had a prevalence of 1.33 per 1,000 and was 5.4 per 1,000 for those older than the age of 65 years.32 Twenty-five percent of chronic edema was related to malignancy; and 29% of patients had at least one episode of cellulitis over the year before the survey; 70% to 80% of patients were female.
Worldwide lymphedema due to filariasis is estimated to affect 100 million individuals33,34 and is considered to be the second leading cause of permanent disability in the world.
For epidemiology, and clinical manifestations and treatment of filariasis see Chapter 207.
Other infectious diseases with lymphedema are much less common and include lymphogranuloma venereum, granuloma inguinale (see Chapters 203 and 204), and tuberculosis (see Chapter 184).
In regions of tropical Africa, Central America, and the Indian subcontinent where filariasis is uncommon, there is a condition of chronic lymphedema that is called podoconiosis, or nonfilarial elephantiasis. This condition causes edematous feet and legs, and is usually bilateral. Podoconiosis is not infectious in origin. It is caused by chronic inoculation of microparticles of silica through the soles of barefoot walkers.17
Typically, patients will present with a persistently edematous extremity without concurrent pain or inflammation (Box 174-4). The foot is often involved first, and initially lesions pit with pressure. Patients presenting later in the disease course may present with nonpitting edema. Feet may illustrate swollen toes with upturned nails. Thickening of the skin over the digits may be present, as may be the Kaposi–Stemmer sign. If the condition has been long-standing, the skin overlying the affected extremity may show generalized thickening, papillomatosis, or verrucous tissue overgrowth (Fig. 174-10). Fungal infections, erysipelas, or viral warts may also be present.
Box 174-4 Common Signs and Symptoms of Lymphedema ||Download (.pdf)
Box 174-4 Common Signs and Symptoms of Lymphedema
- Edematous extremity
- Indentations from socks on standing
- Indentations improve overnight
- Nonpitting edema
- Thickened, woody skin
- Verrucous tissue overgrowth
- “Ski-jump” upturned toe nails
- Infections (bacterial, fungal, viral warts)
Unilateral lymphedema suggests localized obstructing factors, but bilateral lymphedema does not rule out anatomic obstruction, as the obstruction may be in the pelvis or abdomen.
Inflammation as manifested by redness, pain, and swelling is not lymphedema, but can be pyogenic infection, most commonly with S. aureus or Streptococcus pyogenes. Systemic antibiotics should be started before waiting for red lymphangitic streaking. A common complication is contact dermatitis from the use of topical antibiotics or multiple emollients and anti-inflammatory creams.
Chronic venous insufficiency can present with very similar features of early lymphedema. In this clinical context, both conditions will have pitting edema, and the characteristic skin changes in late-stage lymphedema have not yet developed. However, chronic venous insufficiency is typically bilateral, rather than unilateral as in lymphedema. It is imperative to exclude medical causes of lower extremity swelling, such as renal failure, hypoalbuminemia, congestive heart failure, protein-losing nephropathy, pulmonary hypertension, obesity, pregnancy, and drug-induced edema, among others. An uncommon clinical mimic to lymphedema is lipedema of the leg. This syndrome is due to bilateral adipose deposition, usually in the buttocks and lower extremities. This leads to enlargement that stops abruptly at the level of the malleoli, characteristically sparing the feet. This distinctive clinical presentation is referred to as “armchair legs.”17 This condition predominates among overweight women who spend the majority of their time with their legs in a dependent position. Chronic immobility leads to decreased lymphatic drainage and subsequent lymphedema.
Diagnosis of filariasis includes assays to detect filarial antigens, and ultrasound to visualize living adult worms, even in the absence of microfilaremia.34
If there is doubt regarding the clinical diagnosis of lymphedema, especially when trying to differentiate from edema, there are various studies that may be employed for diagnostic confirmation. These include isotopic lymphoscintigraphy or, if necessary, radiocontrast lymphangiography.35,36 Computed tomography (CT) and magnetic resonance imaging (MRI) are other radiographic options, though not ideal. MRI is preferred over CT because of its ability to detect water. These modalities should reveal the characteristic “honeycomb” pattern of the subcutaneous tissue present in chronic lymphedema. This pattern is not present in other types of edema. If there is suspicion for concurrent deep venous thrombosis or venous disease, a venous duplex ultrasound is often required.17
Prolonged lymphedema leads to fibrosis and epidermal hyperplasia with verrucous hyperkeratosis (Fig. 174-10). Ulceration rarely occurs, although the edema and hyperkeratotic changes may be profound. Lymphangiosarcoma, the Stewart–Treves syndrome when associated with postmastectomy lymphedema, is the common lesion in chronically lymphedematous locations (see Chapter 126).
Drug therapy for lymphedema, in general, has been inadequate. Diuretics are frequently prescribed, and not only do they not alleviate the symptoms, they may actually worsen the condition. Diuretics thus should not be used as a primary treatment for lymphedema. There is some evidence to suggest the efficacy of coumarin therapy. Coumarin apparently reduces capillary filtration as well as reduces fibrotic tissue deposition.17
A combination of elevation, exercise, compression garments/devices, skin care aimed to prevent infection, and manual lymphatic drainage, usually via massage, are the mainstay in management of lymphedema.17 In patients with primary and secondary lymphedema, in the absence of venous or arterial disease, manual lymphatic drainage and sequential pneumatic pumps, in addition to compression wraps and garments, may be useful.
Cellulitis or recurrent lymphangitis is a significant problem in lymphedematous sites, and there is both a rationale and results that encourage long-term antibiotic use (e.g., 2.4 million units of benzathine-penicillin G intramuscularly every 2 weeks).37
Microsurgery of lymphatics to bypass obstructed nodes can be considered if nonsurgical treatments are not successful. This procedure is not commonly performed in the United States because it is still considered experimental, but the literature from studies of this procedure performed in Europe is considerable. The surgery consists of the formation of multiple end-to-end lymphatic–venous anastomoses.38 Congenital lymphatic disorders have been treated with this intervention in the early childhood years with dramatic results.39,40
Low-level laser therapy (LLLT), either in combination with pneumatic compression or as a solo intervention, has been studied in patients with postoperative lymphedema, primarily in postmastectomy lymphedema. Results are encouraging, and patients have had improvements in the total volume of affected limbs at follow-up analysis of up to 1 year.41
Excisional or suction-assisted lipectomy (liposuction) may be an option in selected patients in whom are not eligible for other treatment options, or in whom other therapeutic modalities have failed.
Any patient with lymphedema, whatever the cause, should keep their feet dry, nails trimmed, and prevent and aggressively treat pyogenic infection. Lymph moves faster during limb activity and exercise (e.g., walking should be encouraged). A combination of flexibility training, aerobic training, and strengthening exercises—while wearing compression garments or devices—have shown to have significant improvement in lymphedema.17