Swelling of the back of the foot

Introduction Lymphedema showed early depression and edema in the back of the foot. Lymph is a tissue fluid in the interstitial space that flows back into the vein via the lymphatics. The lymphatic circulation is also the physiological and functional physical circulation of the human body. Congenital dysplasia of the lymphatic system or occlusion or destruction for some reason, the distal lymphatic drainage is impaired, and the lymphatic fluid in the interstitial space is abnormally increased. If it occurs in the limb, the uniformity of the affected limb is thickened. At first, the skin is still smooth and soft, and the edema of the affected limb can be obviously subsided.

Cause

(1) Causes of the disease

Primary lymphedema (Milroy's disease) is a dominant hereditary disease that may be associated with abnormal embryonic development. Secondary lymphedema is caused by malignant tumor compression, surgical destruction, radiation exposure, filariasis, lymph node resection, and various infections. It causes lymphatic edema after several months or even years. Lymphedema is common in the tropics, but sometimes it is impossible to find a cause. Filariasis is one of the causes of lymphedema in some countries. Although the effect of bacterial infection on lymphatic obstruction is not certain, recurrent erysipelas and chronic cellulitis can damage lymphatic vessels and further accelerate the development of this disease. Similar lesions can also be found in tissues surrounding chronic ulcers.

(two) pathogenesis

Lymph is a tissue fluid in the interstitial space that flows back into the vein via the lymphatics. The lymphatic circulation is also the physiological and functional physical circulation of the human body. Congenital dysplasia of the lymphatic system or occlusion or destruction for some reason, the distal lymphatic drainage is impaired, and the lymphatic fluid in the interstitial space is abnormally increased. If it occurs in the limb, the uniformity of the affected limb is thickened. At first, the skin is still smooth and soft, and the edema of the affected limb can be obviously subsided.

Because the accumulated lymph is rich in protein, it can be as high as 5.8g/dl, [normal 0.72g/dl] long-term stimulation causes abnormal growth of connective tissue, and adipose tissue is replaced by a large amount of fibrous tissue. The skin and subcutaneous tissue are extremely thickened, the surface of the skin is keratinized, rough, and there is no indentation after finger pressure, and there is a sputum-like growth, forming a typical "like skin swelling". Infection increases the inflammatory exudate, stimulates a large number of connective tissue hyperplasia, destroys more lymphatic vessels, aggravates lymphatic retention, increases the chance of secondary infection, and forms a vicious circle, which causes lymphedema to become more and more serious.

The formation of lymphedema is summarized in Figure 1.

Histopathology: The main lesion of primary lymphedema is in the dermal reticular layer and subcutaneous tissue, and there are more lymph fluid in the interstitial space. Part of the collagen fibers in the dermal papilla are hyaline denatured. There are varying degrees of lymphocytic infiltration around the blood vessels. In the early stage of secondary lymphedema, there is inflammatory cell infiltration, advanced tissue fibrosis, and its epidermis is verrucous hyperplasia.

an examination

Related inspection

Joint examination of bone and joint soft tissue CT

There are many different causes of lymphedema, taking into account the etiology and clinical types, mainly divided into two major categories: primary and secondary. Most of the primary lymphedema is caused by congenital dysplasia such as lymphatic expansion, valvular insufficiency or absence. According to lymphangiography, primary lymphedema can be classified as follows:

1 lymphatic hypoplasia with subcutaneous lymphoid deficiency;

2 lymphatic hypoplasia, lymph nodes and lymphatic vessels are small and small;

3 lymphatic hyperplasia, with lymph nodes and lymphatic vessels large and large, with distortion and varicose. Lymphatic hypoplasia is very rare, common in congenital lymphedema. Development is lower than the most common type. Both simple and atrophic lymphedema are congenital. Early onset lymphedema is more common in adolescent women or young women, and the symptoms are aggravated during menstruation. Therefore, the cause may be related to endocrine disorders, accounting for 85-90% of primary lymphedema. After the onset of 35 years old, it is called delayed lymphedema. Secondary lymphedema is mostly caused by blockage of lymphatic vessels. The most common in China is filariasis lymphedema and streptococcal infectious lymphedema. Upper extremity lymphedema after breast cancer radical surgery is not uncommon.

classification:

(a) primary lymphedema

1. Congenital: simple, hereditary (milroy disease)

Early onset

(B) secondary lymphedema

1. Infectivity: parasites, bacteria, fungi, etc.

2. Injury: surgery, radiotherapy, burns, etc.

3. Malignant neoplasms: primary tumors, secondary tumors

4. Others: systemic diseases, pregnancy, etc.

According to the cause classification, their respective clinical characteristics are described as follows:

(1) Congenital lymphedema is divided into two categories:

1. There is no family or genetic factor in simple onset. The incidence rate accounts for 12% of primary lymphedema. After birth, there is one side of the limb limitation or diffuse swelling, no pain, no ulcers, rarely concurrent infection, generally good, more common in the lower limbs.

2. Hereditary, also known as Milroy disease, is rare. Many people in the same family are sick, that is, after the birth, most of them are affected by one lower limb.

(2) Women with early onset lymphedema are more common, the ratio of male to female is 1:3, the age of onset is 9 to 35, and 70% is unilateral. Generally, there is mild swelling of the ankle and foot without obvious lure, and it is aggravated when standing, active, menstrual period and warm climate. Refers to high limb edema can be temporarily relieved. The lesion gradually worsens and spreads to the calf, but generally does not exceed the knee joint. In the later stage, it can be a typical "skin-like leg", but there are few complicated ulcers and secondary infections.

(3) Infectious lymphedema includes infections such as bacteria, fungi, and filamentous insects. Cracks or blisters on the skin of the toes are the most common route of invasion of pathogenic bacteria. Secondly, varicose veins of the lower extremities and secondary ulcers and other local injuries or infections are also the path of bacterial invasion. In addition, pelvic lymphadenitis caused by female pelvic inflammatory disease can cause lymphatic reflux in the lower limbs and cause lymphatic swelling in the affected limb. Streptococcus is the most common pathogen for secondary infections. Clinically characterized by recurrent acute cellulitis and acute lymphangitis, systemic symptoms are severe, with chills, high fever accompanied by nausea, vomiting, local sulcus lymphadenopathy with tenderness. After anti-inflammatory symptomatic treatment, the systemic symptoms subsided quickly, but the local lesions were relieved slowly and easily. After each episode, the swelling of the lower extremities is aggravated, and finally the skin is rough and has a sickle-like growth, and a few can be chronic ulcers.

Lymphatic edema is also caused by the foot itself or secondary infection, which is generally limited to the foot and the back of the foot. Severe fungal infections are often a precursor to acute cellulitis and acute lymphangitis. Controlling fungal infections is one of the effective measures to prevent lymphedema.

Filariasis is a common cause of lower limb lymphedema in the southeastern coastal areas of China. The incidence rate is 4 to 7%, which is more common in men. Filariasis has different degrees of fever and local pain during the initial stage of infection. Repeated filarial infection causes local lymphatic stenosis, occlusion, and destruction of the lower extremities, and the lymphatic fluid reflux of the distal skin and subcutaneous tissue is blocked, and lymphedema occurs. Local lesions such as athlete's foot or secondary erysipelas-like recurrent episodes of lymphatic drainage and infection are causal, forming a vicious circle and eventually becoming a typical "skin-like leg." Its flash, scrotal lymphedema is not uncommon, and the scrotum can be extremely swollen in the late stage. This is also a major feature of filarial infectious lymphedema.

(D) Injury lymphedema is mainly divided into postoperative lymphedema and lymphedema after radiotherapy.

1. Lymphedema after surgery often occurs after lymph node dissection, and lymphatic edema on one side of the upper limb caused by radical mastectomy is particularly common. After extensive lymph node dissection, the distal lymphatics are blocked, and the lymph fluid stimulates tissue fibrosis, which causes the swelling to increase. The time of lymphedema after surgery is quite different. Generally, the limbs begin to move and there is mild swelling of the proximal limbs, but it can also occur several weeks or even months after surgery.

2. Lymphedema depth after radiotherapy X-ray and radium infusion therapy caused local tissue fibrosis, lymphatic occlusion caused lymphedema.

(5) Both malignant neoplastic lymphedema and secondary lymphoid malignancies can block lymphangiogenesis in lymphatic vessels. The former is found in Hodgkin's disease, lymphosarcoma, Kaposi multiple hemorrhagic sarcoma and lymphangiosarcoma. Although lymphangiosarcoma is rare, it is the result of long-term lymphedema and malignant transformation. It occurs mostly in patients with lymphedema after limbic radical mastectomy. It usually occurs 10 years after surgery. The skin first appears red or purple spots, showing multiple Later, it merges into an ulcerated mass. Limb edema of the limbs is more serious after onset. A biopsy should be performed in a timely manner. Amputation is required after the diagnosis is clear.

Secondary lymphatic lesions are metastatic lesions of breast, cervix, labia, prostate, bladder, testis, skin, internal iliac and other cancers. Sometimes the primary lesion is small, not easy to find, clinical manifestations of chronic meridian, painless, progressive lymphedema. Therefore, for lymphedema with unknown causes, the possibility of tumor should be guarded, and lymph node biopsy should be diagnosed if necessary.

In addition, pregnancy and many systemic diseases such as pneumonia, influenza, typhoid, etc. can also lead to recurrent cellulitis and lymphangitis, as well as venous thrombosis and lymphatic obstruction leading to lymphedema.

Differential diagnosis

Plantar and foot edema: Postural flat feet can present symptoms of plantar and dorsal edema.

Ankle and foot edema: Ankle and foot edema are clinical manifestations of lymphedema. Lymphedema is slower onset, and it is more common to swollen the back of the foot.

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