The “big leg” is the colloquial term used to define the increased volume of lower limb. The most common cause, lymphedema of the lower limbs will be developed here and the other differential diagnoses will be cited.
CLASSIFICATION lymphoedema LOWER LIMB:
We define two types of lymphedema of the lower limbs: the primitive and secondary lymphedema. 
This is lymphedema without appearing notion of prior damage pathways or lymph nodes. The age of onset is generally less than 25 years (or in adolescence or in childhood), with a marked female predominance.
The vast majority of cases are sporadic with no family history of lymphedema. Lymphedema affects either a single leg in whole or both members distally (below the knee). It usually begins with the back of the foot and ankle and goes up more or less quickly to the limb. In the initial phase, there is a certain reversibility with “disappearance” of lymphedema after a night of supine or rest. This is followed by a fixity of lymphedema with a tendency of the skin to become firm and thick. More diffuse associated disorders (upper limb, face, genitals) evoke more complex lymphatic malformations can be part of malformations disease and / or genetic. Upon occurrence of a primitive lymphedema, it is conventional to find a trigger. It is tempting to attribute a cause lymphedema when it would be better to speak of decompensation factor (ankle sprain, pregnancy, sporting effort, long drive, insect bites, sclerotherapy, arterial bypass, erysipelas) or lymph anomalies are existing.
They are less common than those of the upper limb (after breast cancer treatment) but their causes are many and varied. Cancers are responsible for the majority of secondary lymphedema of the lower extremity in France while the world filariasis is the main cause. Among cancers, those whose treatment includes pelvic lymph node dissection and / or inguinal are responsible for lymphedema: cervical cancer, endometrial, ovarian, vulva, testis, bladder, prostate , rectum, melanoma of lower limb. Secondary lymphedema preferentially start with the proximal part of the limb (thigh) and a fickle downward trend, sometimes without injury to the foot.
Among these cancers, cervical (treated with surgery, radiotherapy or brachytherapy) frequently causes lymphedema uniform but usually bilateral (and unbalanced) starting proximally and then touching the pubic bone or abdomen and genitals external (large and small lips). Lymphomas Hodgkin or non-Hodgkin’s can also complicate lymphedema or after inguinal node biopsies for diagnostic purposes or after irradiation of the regional lymph nodes. Kaposi’s sarcoma, Human Herpes Virus virus (HHV-8) can be accompanied by lymphedema because this virus has a tropism for lymphatic endothelial cells.
Rheumatic diseases (rheumatoid arthritis, psoriatic arthritis, spondyloarthritis) may be associated with lymphoedema in the limbs where the disease is active. Do not forget to mention certain causes “benign”. Indeed, any inguinal lymph node biopsy or resection at diagnosis or treatment, can cause lymphedema of the lower extremity: tuberculosis, sarcoidosis, infectious adenitis, etc.
The impression of red tape is the most common symptom, sometimes described as a feeling of heaviness in the limb lymphedema.
The pain is much less common, sometimes present at the beginning of lymphoedema with a skin tension impression. Lymphedema causes skin changes characteristics. bending the folds are accentuated at the ankle and toes, while there is an elastic swelling of the back of the foot (Fig. 1, see also figure in the color specifications). Stemmer’s sign is almost pathognomonic: it is impossible to wrinkle the skin of the dorsum of the second toe. The toes are also taking a “square” aspect.
It is sometimes observed nail disorders with detachment of the tablet, shortening the nail tends to be erectile. Search intertrigo interorteil, potential infectious door entrance, is fundamental because lymphedema of the lower limbs is the most important risk factor in the occurrence of erysipelas.
Assessment of the volume of lymphedema:
It is essential to measure the volume of lymphedema, before / after treatment and at follow-up, as for the upper limb.The reference technique is the water volume which assesses the volume of the member in full including hands and feet. This method is rarely used in clinical practice for the benefit of volumetric measurements estimated by calculation.
Indeed, the perimeter measures taken at regular intervals (every 5 to 10 cm) are used to calculate a volume in ml by assimilating members of segments of truncated cones.
The diagnosis of lymphedema is primarily clinical. Additional tests may be useful and have two distinct objectives. The first is to look for a cause to explain the appearance or worsening of secondary lymphedema and the second to assess lymphedema itself.
The appearance of a lower limb lymphedema can be related to pelvic lymph node or local tumor recurrence after treatment of cancers. The scanner, MRI or PET scan are useful in these situations. A venous duplex ultrasound is necessary in search of venous thrombosis can be the trigger of secondary lymphedema.
Explorations of lymphedema itself:
Lymphoscintigraphy replaced direct lymphography was painful, technically difficult and could increase the lymphedema. The radioactive tracer (nanocolloid rhenium or albumin labeled with Technetium 99m) is injected at the interstitial tissue of the first interdigital space of each member to study with images taken after 40 to 60 minutes. This examination allows a morphological study (lymphatics, inguinal nodes, rétrocruraux, para-aortic) and functional (half-life plotter speed). Lymphoscintigraphy is especially useful in difficult situations and to confi rm primitive lymphedema where it may show a decreased uptake of the tracer in the affected area (Fig. 2). In secondary lymphedema, the interest of lymphoscintigraphy is low. Indeed, it shows most of the time, the disappearance of nodes in the area that received the surgery and / or radiotherapy.
Lymphedema is usually just a clinical diagnosis but in some atypical situations must know evoke and eliminate other diseases.
This is an abnormal distribution of adipose tissue, hips ankle with respect of the foot. Involvement is bilateral, sometimes asymmetrical and occurs almost exclusively in obese women with the notion of identical family history. The skin is sensitive to the pinch, unlike lymphedema and spontaneous bruising are common. There is no real edema, except after prolonged standing position or sign of Stemmer. Treatment is difficult because weight loss improves the morphology little while weight gain worsens.
It represents a responsible pluritissulaire reached during the hot phase of pain, increased local heat, sweating and edema. Although little studied, this edema has some characteristics of lymphedema. However, pain, infrequent in lymphedema, allows to the diagnosis and bone scan and / or MRI can confirm it.
These edemas are self-induced by the patient using a localized necking (foot, calf).
These edema have a lymphatic and venous component. The discovery of the groove allows suggest the diagnosis.These behavioral disorders are difficult to take to load and integrate in complex psychiatric disorders.
Severe venous insufficiency is associated with lymphatic insufficiency by exceeding the capacity of fluid reabsorption lymph capillaries. This then promotes lymphatic insufficiency occurred erysipelas.
Edema after arterial bypass surgery:
They are very common after bypass femoropopliteal using either saphenous vein or polytetrafluoroethylene, to treat occlusive arterial disease, and estimated between 50 and 100% of cases. There is a lymphatic involvement, deep vein thrombosis being involved in fewer than 10% of cases. These swellings appear in the days following surgery last few weeks but may last longer. Any action on the groin, hip or knee can also cause lymphedema of lower limb (venous surgery: stripping, orthopedic surgery: hip prosthesis).
Other causes of edema:
They must be eliminated in case of uncertain diagnosis of lymphedema. Edema of cardiac origin (or renal) are symmetrical, are clearly the bucket, and preferably occur in the elderly. Edema of renal origin are symmetrical and sloping.
Lymphedema is the main risk factor for occurrence of erysipelas at the lower limb. The front door can be a interorteil intertrigo, an insect bite or even a small wound. Erysipelas reached the lymphedema area and may extend to the external genitalia. The frequency of erysipelas is variable, ranging from a single episode to multiple relapses while requiring anti-infective prophylaxis for long periods.
The lower limb lymphedema treatment is identical to that of the upper limb.
It is based on the prevention of infections (erysipelas) avoiding risk procedures (cuts, scratches) and treating infectious gateways (intertrigos interorteils fungal, ingrown toenails, dry skin responsible for cracks). Sometimes the nails are erection, their cut is difficult and requires regular follow-pedicure podiatry. The other side of the management is to reduce the volume of lymphedema. The complete decongestive physiotherapy treatment called is divided into two phases: the first intensive is intended to reduce the volume and secondary care to maintain the reduced volume. The main element is the daily application, 24h / 24h, bit of elastic bandages with bands short stretch (<100%) (Somos) on a foam padding and / or cotton, possibly preceded by manual lymph drainage . The duration of the intensive treatment varies from 2 to 3 weeks. During the maintenance phase, after obtaining a reduction in volume, the port, the day of elastic compression is essential . The lower thigh are preferable to low hock (socks), feet closed to foot open due to risk of worsening of lymphedema toes. The superposition of low high class (class 3, 4) is usually required. Their wear requires regular replacement every 3 to 4 months. Achieving little elastic bandages at night by the patient himself after learning with a physical therapist at a frequency lower than that of intensive treatment (3 per week) is associated with daytime port of elastic compression. Skin Care with regular moisturizing in the evening is often necessary. If overweight, weight loss can promote the reduction in volume of lymphedema. The veinotonic drugs are very effective and banned diuretic.