The main symptom associated with hereditary lymphedema is edema in different parts of the body due to accumulation of lymph in the soft layers of tissue under the epidermis. Swelling frequently occurs in one or both legs, but may also be present in the trunk, face, genitalia and arms. When lymphedema develops in the legs, swelling is usually most noticeable in the foot and ankle but may also be present in the calf and thigh. In some people, swelling may cause tightness, discomfort and unusual tingling sensations (paresthesias) in the affected areas. The affected area heals poorly even after minor trauma (e.g., cut or insect bite). The skin of the affected area may become abnormally dry, thickened or scaly skin (hyperkeratosis) resulting in a “woody” texture.
Hereditary lymphedema type I (Milroy disease) is characterized by edema that is present at or shortly after birth (congenital). Ultrasound scanning during pregnancy may indicate if a fetus is affected if swelling of the dorsum of the feet is noted in the second or third trimester. In rare cases, edema may develop later in life. The legs are most often affected, and in some patients, the genitals may also be affected. The extent and location of edema varies greatly from person to person even among individuals in the same family. Additional complications sometimes associated with hereditary lymphedema type I include upslanting toenails, small warty growths on the affected areas (papillomatosis), abnormally large or prominent veins below the knees and in males, urethral abnormalities and the development of a fluid-filled sac along the spermatic cord of the scrotum (hydrocele). Bacterial infection of the skin and underlying soft tissues (cellulitis) has also been reported in approximately 20% of individuals, which may increase swelling due to additional damage to lymphatic vessels.
Hereditary lymphedema type II (Meige disease or lymphedema praecox) develops around puberty or shortly thereafter in most individuals. This is the most common type of primary lymphedema. In addition to lymphedema of the legs, other areas of the body such as the arms, face and voice box (larynx) may be affected. Some individuals may develop yellow nails.
Lymphedema tarda is defined as primary lymphedema occurring after the age of 35. Edema primarily occurs in the legs, but the arms and other areas may be affected as well. In women, the lower extremities are most often affected.
In all subtypes of hereditary lymphedema, the degree of edema can progress; in some people, especially in early years, edema may improve over time. Obesity makes management of lymphedema more difficult. Affected individuals with lymphedema are at risk for developing infections including cellulitis or infection of the lymphatic vessels (lymphangitis). These infections are characterized by areas of warm, painful and reddened skin. Red skin “streaks” may also develop in the infected area. Increased edema is common. A general feeling of ill health (malaise), fever, chills and/or Headaches may also occur. If left untreated, cellulitis can lead to septicemia, skin abscesses, areas of ulceration and/or tissue damage (necrosis). Cellulitis is more common in males than females. Athlete’s foot (tinea pedis) can cause cracks in the interdigital skin, bacterial invasion and cellulitis. Pregnant individuals with hereditary lymphedema may experience increased swelling during pregnancy.
In rare cases, additional complications can include accumulation of milky fluid consisting of fat droplets and lymph (chyle). Chyle is absorbed during digestion by the lymphatic vessels located around the intestine and drains into the thoracic duct in the upper chest before being deposited into veins, where it mixes with blood. In some individuals with hereditary lymphedema, the lymphatic vessels may rupture or become blocked (obstructed), causing chyle to accumulate in the chest cavity (chylothorax) or abdomen (chylous ascites).
Affected individuals may also be at a greater risk than the general population for developing a malignancy at the affected site. These malignancies include angiosarcoma, which are cancerous tumors that develop from blood or lymphatic vessels. They may occur in any area of the body. A specific type of angiosarComa is known as lymphangiosarcoma, or Stewart-Treves syndrome. Rarely, this cancerous tumor may develop in long-standing cases of primary or secondary lymphedema. AngiosarComa occurs in the lymphedematous extremity but can spread to the adjacent trunk and lungs.