[Primary lymphedema in childhood]

Current Concepts in the Management of Primary Lymphedema

Primary lymphedema is a heterogeneous group of conditions encompassing all lymphatic anomalies that result in lymphatic swelling. Primary lymphedema can be difficult to diagnose, and diagnosis is often delayed. As opposed to secondary lymphedema, primary lymphedema has an unpredictable disease course, often progressing more slowly. Primary lymphedema can be associated with various genetic syndromes or can be idiopathic. Diagnosis is often clinical, although imaging can be a helpful adjunct. The literature on treating primary lymphedema is limited, and treatment algorithms are largely based on practice patterns for secondary lymphedema. The mainstay of treatment focuses on complete decongestive therapy, including manual lymphatic drainage and compression therapy. For those who fail conservative treatment, surgical treatment can be an option. Microsurgical techniques have shown promise in primary lymphedema, with both lymphovenous bypass and vascularized lymph node transfers demonstrating improved clinical outcomes in a few studies.

Primary lymphedema French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins)

Primary lymphedema is a rare chronic pathology associated with constitutional abnormalities of the lymphatic system. The objective of this French National Diagnosis and Care Protocol (Protocole National de Diagnostic et de Soins; PNDS), based on a critical literature review and multidisciplinary expert consensus, is to provide health professionals with an explanation of the optimal management and care of patients with primary lymphedema. This PNDS, written by consultants at the French National Referral Center for Primary Lymphedema, was published in 2019 (https://has-sante.fr/upload/docs/application/pdf/2019-02/pnds_lymphoedeme_primaire_final_has.pdf). Primary lymphedema can be isolated or syndromic (whose manifestations are more complex with a group of symptoms) and mainly affects the lower limbs, or, much more rarely, upper limbs or external genitalia. Women are more frequently affected than men, preferentially young. The diagnosis is clinical, associating mild or non-pitting edema and skin thickening, as confirmed by the Stemmer’s sign (impossibility to pinch the skin on the dorsal side or the base of the second toe), which is pathognomonic of lymphedema. Limb lymphoscintigraphy is useful to confirm the diagnosis. Other causes of swelling or edema of the lower limbs must be ruled out, such as lipedema. The main acute lymphedema complication is cellulitis (erysipelas). Functional and psychological repercussions can be major, deteriorating the patient’s quality of life. Treatment aims to prevent those complications, reduce the volume with low-stretch bandages, then stabilize it over the long term by exercises and wearing a compression garment. Patient education (or parents of a child) is essential to improve observance.