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Erythematous nodules of lower extremities

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction Lower extremity erythema nodules are one of the clinical manifestations of nodular erythema. The nodular erythema is an acute inflammatory disease caused by dermal vasculature and lipid membrane inflammation, which is more common in young and middle-aged women. It is generally believed that the disease is associated with streptococcal infection and drug response.

Cause

Cause

The etiology of the disease is complex and is generally thought to be associated with infections, especially streptococcal infections and drug reactions. In addition, tuberculosis is also an important predisposing factor, especially for children. Infections such as viruses and fungi, and drugs such as bromide, iodide, and sulfonamide can also induce the disease.

1. Streptococcal infection: Some patients may develop after upper respiratory tract infection, angina and acute tonsillitis.

2. Tuberculosis infection: Since Uffelmana proposed in 1872 that the disease is related to tuberculosis infection, it has gradually attracted people's attention. More and more evidence indicates that the disease is closely related to tuberculosis infection. Domestic statistics combined with tuberculosis infection, or old tuberculosis lesions, or positive test of tuberculosis, accounted for more than 60%, the disease is considered to be allergic to the tuberculosis or its toxins.

3, other reasons: some drugs, especially bromine and sulfa drugs, is the most common cause of the disease. Others such as coccidioidomycosis, histoplasmosis, feline fever, tickosis, ulcerative colitis, sarcoidosis, Behcet's disease, leprosy and sexually transmitted lymphogranuloma may be associated with nodularity erythema. In addition, viral infections are associated with the disease, and other rare causes such as acute vulvar ulcers, acute or chronic leukemia, may also be associated with the disease.

Pathogenesis

1. The disease is a skin allergy caused by many causes, and the true pathogenesis is still unclear. Some people think that it is an allergic vasculitis, but the use of immunofluorescence technology has not found immune complex deposition in necrotic or allergic vasculitis. It has also been suggested that the disease is a delayed allergic reaction of blood vessels to microorganisms or other antigens.

2. The main pathological changes occur in the subcutaneous fat layer and the subdermal fat leaflet interval. In the early stage of acute inflammatory response, mainly neutrophil infiltration, accompanied by a small amount of lymphocytes, eosinophils and a small amount of red blood cell extravasation. As the disease progresses, neutrophils quickly disappear and are replaced by lymphocytes, plasma cells, and histiocytes. In the fat leaflet interval, giant cells can be present with significant fibrin exudation. Thickening of the vessel wall, endothelial cell proliferation and luminal occlusion, no abscess and caseous necrosis, the epidermis is generally normal.

Examine

an examination

Related inspection

Spores agglutination test

First, the symptoms

Nodular erythema is a common nodular skin disease caused by vasculitis. It is common in red or purple-red painful inflammatory nodules on the calf extension. Young women are more common, and the course of disease is limited and easy to relapse. . Before the onset, there was a history of infection or medication, and the lesions suddenly occurred. They were bilaterally symmetric subcutaneous nodules, ranging from broad beans to walnuts, with a number of 10 or more, conscious pain or tenderness, moderate hardness. Early skin color is reddish, the surface is smooth, slightly bulged, and after a few days, the skin color turns dark red or blue, and the surface flattens. After 3 to 4 weeks, the nodules gradually subsided, leaving temporary pigmentation, and no ulcers in the nodules. Skin lesions occur in front of the sputum, but also in the thighs, upper arm extensions and neck, rarely seen on the face. Chronic nodular erythema is different from acute nodular erythema. It often occurs in elderly women. The skin lesions are unilateral. If they are bilateral, they are asymmetrical. Except for joint pain, there are no other systemic symptoms. The nodules are not painful and softer than acute nodular erythema.

Second, check

1, blood routine examination: white blood cell count is generally normal or slightly elevated, but in the early stage, accompanied by high fever, tonsillitis or pharyngitis, white blood cell count and neutrophil count can be significantly increased. Rheumatoid factor can also be positive. Some people have measured the increase of serum P2 microglobulin in patients.

2, immunological examination: tuberculin test can be positive when accompanied by tuberculosis.

3, X-ray examination: When the primary disease is tuberculosis, the hilar lymphadenopathy can often be found. The literature reports that young women between the ages of 16 and 30 have nodular erythema, X-ray shows a double hilar lymphadenopathy, known as the Buner syndrome, and it is believed that this type of patient has hilar lymphadenopathy, which is actually A manifestation of systemic nodular erythema.

Diagnosis

Differential diagnosis

Differential diagnosis of lower limb erythema nodules:

1, hard erythema: mostly occurs in the flexor of the calf, often single or several, the lesion is larger than the nodular erythema, the disease is long, can spontaneously rupture, form an ulcer, leaving a different degree of atrophy after healing.

2, return to febrile nodular non-suppurative panniculitis: regression of febrile nodular non-suppurative panniculitis is nodular erythematous lesions, mainly located in the chest, abdomen, thighs, buttocks, clusters appear, disappear After the local atrophy and dishing depression, there was fever in each episode, and the pathological change was adipose tissue.

3, subacute nodular migratory panniculitis: subacute nodular migratory panniculitis occurs in the calf nodular erythematous rash, usually in the early stage of the disease can occur in one side, painless, centrifugal Sexual enlargement, bright red edge, whitening at the center, can gradually flatten and form plaques, the size is 10 ~ 20cm, duration from two months to two years, showing pigmentation, also known as migratory nodular erythema .

4, nodular vasculitis: the disease occurs in middle-aged women. The nodules are mainly located on the lateral and posterior sides of the calf. After a slow, occasional rupture.