Lymphedema, also known as lymphoedema and lymphatic edema, is a condition of localized swelling caused by a compromised lymphatic system. The lymphatic system functions as a critical portion of the body's immune system and returns interstitial fluid to the bloodstream. Lymphedema is most frequently a complication of cancer treatment or parasitic infections, but it can also be seen in a number of genetic disorders. Though incurable and progressive, a number of treatments may improve symptoms. Tissues with lymphedema are at high risk of infection because the lymphatic system has been compromised.
While there is no cure, treatment may improve outcomes. This commonly include compression therapy, good skin care, exercise, and manual lymphatic drainage (MLD), which together are known as combined decongestive therapy. Diuretics are not useful.
The most common manifestation of lymphedema is soft tissue swelling, edema. As the disorder progresses, worsening edema and skin changes including discoloration, verrucous (wart-like) hyperplasia, hyperkeratosis, papillomatosis, dermal thickening, and ulcers may be seen. Additionally, there is increased risk of infection of the skin, known as erysipelas.
When lymphatic impairment becomes so great that the lymph fluid exceeds the lymphatic system's ability to transport it, an abnormal amount of protein-rich fluid collects in the tissues. Left untreated, this stagnant, protein-rich fluid causes tissue channels to increase in size and number, reducing oxygen availability. This interferes with wound healing and provides a rich culture medium for bacterial growth that can result in skin infections, lymphangitis, lymphadenitis, and, in severe cases, skin ulcers. It is vital for lymphedema patients to be aware of the symptoms of infection and to seek immediate treatment, since recurrent infections or cellulitis, in addition to their inherent danger, further damage the lymphatic system and set up a vicious circle.
In rare cases, lymphedema may lead to a form of cancer called lymphangiosarcoma, although the mechanism of carcinogenesis is not understood.