What Is Erythema Nodosum?

Nodular erythema is an acute inflammatory disease mainly involving subcutaneous adipose tissue, which is more common in young and middle-aged women. It is generally believed that the disease is related to multiple factors. Nodular erythema is common in the extension of the calf, with clinical manifestations of red or purplish painful inflammatory nodules. It is more common in young women, and has a limited course and is prone to relapse.

Basic Information

Visiting department

dermatology

Multiple groups

Young women

Common locations

Calf extension

Common causes

Related to infections, drugs, estrogen and other diseases

Common symptoms

Red or mauve painful inflammatory nodules

Contagious

no

Causes of nodular erythema

The etiology of the disease is complex and is generally thought to be related to infections, drugs, estrogen and other diseases.

Streptococcal infection

Some patients can occur after upper respiratory infections, angina, and acute tonsillitis.

2. Tuberculosis infection

There is growing evidence that the disease is closely related to tuberculosis infection. Domestic statistics also combined with tuberculosis infection, or old tuberculosis lesions, or positive tuberculosis test, accounted for more than 60%, the disease is considered to be allergic to tuberculosis or its toxins.

3. Drug

Certain drugs, especially bromine, sulfa drugs, and oral contraceptives, are the most common causes of the disease.

4. Delayed allergies

The disease is a skin allergy caused by many causes, and the true pathogenesis is unknown. Some people think that the disease is a delayed allergic reaction of blood vessels to microorganisms or other antigens.

5. Other diseases

Others such as autoimmune disease, ulcerative colitis, and sarcoidosis can be accompanied by nodular erythema. In addition, acute and chronic leukemia can also be associated with the disease.

Clinical manifestations of nodular erythema

Nodular erythema is common in the extension of the calf, with clinical manifestations of red or purplish painful inflammatory nodules. It is more common in young women, and has a limited course and is prone to relapse. Before the onset, there was a history of infection or medication. The skin lesions suddenly occurred. They were bilaterally symmetrical subcutaneous nodules, ranging from broad beans to walnuts. The number was 10 or more. The pain was painful or tender. Early skin color was reddish, the surface was smooth and slightly bulged. After a few days, the skin color turned dark red or cyan, and the surface became flat. After 3 to 4 weeks, the nodules gradually subsided, leaving temporary pigmentation, and nodules did not occur. Skin lesions are more common in front of the shin, but also in the thighs, upper arms, and neck, and are 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, and if bilateral, it is asymmetric, with no systemic symptoms except joint pain. Nodules are painless and softer than acute nodular erythema.

Nodular erythema

Blood test

The white blood cell count is usually normal or slightly elevated, but in the early stages, accompanied by high fever, tonsillitis, or pharyngitis, the white blood cell count and neutrophil count can be significantly increased. ESR was increased in 2/3 of the patients. Rheumatoid factor can also be positive. Some people have determined that patients with elevated serum ₂ microglobulin.

2. Immunological examination

The tuberculin test can be positive when accompanied by tuberculosis.

3.X-ray inspection

When the primary disease is pulmonary tuberculosis, hilar lymphadenopathy can often be found. It is reported in young women who are 16 to 30 years old with nodular erythema and whose X-ray shows double hilar lymphadenopathy, called Buner syndrome. It is believed that hilar lymphadenopathy in this type of patients is actually A manifestation of systemic nodular erythema.

4. Pathological examination

The main pathological changes occurred in the subcutaneous fat lobular septum. In the early stage of the acute inflammatory response, neutrophil infiltration is mainly accompanied by a small amount of lymphocytes, eosinophils, and a small amount of extravasation of red blood cells. As the disease progresses, neutrophils quickly disappear, and they are replaced by lymphocytes, plasma cells, and histiocytes. In the fatty lobular septum, giant cell and granulomatous changes can occur. Vascular and fatty lobules were not obvious.

Nodular erythema diagnosis

According to the typical skin damage, it usually occurs in front of the lower leg of the calf, with tenderness, no ulceration, history of infection before onset, history of taking drugs (sulfa, contraceptives, bromine and iodine, etc.), and combined with skin histopathological examination showed Subcutaneous fat lobular septal panniculitis can be diagnosed.

Differential diagnosis of nodular erythema

Hard erythema

It usually occurs in the flexion of the calf, often single or several, and the skin lesions are larger than nodular erythema, with a long course, which can spontaneously rupture, form ulcers, and leave different degrees of atrophy after healing.

2. Regression of febrile nodular non-purulent panniculitis

Fever nodular non-purulent panniculitis is nodular erythematous skin lesions, which are mainly located in the chest, abdomen, thighs, and buttocks, appear in clusters, and local atrophy and dish-shaped depressions remain after disappearance. Fever, pathological changes to subcutaneous fatty lobularitis.

3. Subacute nodular nodular panniculitis

Subacute nodular nodular panniculitis occurs in the nodular erythematous rash of the lower leg. It usually occurs on one side early in the course of the disease. It is painless, with centrifugal enlargement, bright red edges, whitening in the center, and gradually flattens The formation of plaques, ranging in size from 10 to 20 cm, lasts from two months to two years, and manifests with pigmentation, also known as migratory nodular erythema.

Nodular erythema treatment

Systemic treatment

(1) Find the cause and treat accordingly. In the acute stage, you can rest in bed, raise the affected limb, and avoid cold and strong labor. Those with obvious infections can cooperate with antibiotics.

(2) For those who have pain, oral analgesics and non-steroidal anti-inflammatory drugs such as indomethacin (indomethacin) and ibuprofen can be taken orally. If you have obvious infection, give antibiotics. In severe cases, corticosteroids, such as prednisone (prednisone), or betamethasone / betamethasone dipropionate (depotsonson), are given intramuscularly once every 3 weeks to quickly control the condition. In addition, 10% potassium iodide mixture can be used 3 times a day for 2 to 4 weeks. This method is safe and effective, but it should be noted that long-term application can lead to hypothyroidism. For those who are stubborn, hydroxychloroquine and dapsone can be used, as well as the traditional Chinese medicine Tripterygium wilfordii or Kunming Shanhaisu tablets. Systemic treatments can also use UV, wax, diathermy, or audio electrotherapy.

Local treatment

The principle of local treatment is anti-inflammatory and analgesic. Topical fish boron ointment, 10% camphor ointment dressing or 75% alcohol topical wet compress, and topical corticosteroid ointment can have analgesic effect. It can also be injected intradermally with about 0.3 ml of triamcinolone suspension plus 2% procaine solution, which has a significant effect on those who have persistent severe pain in the nodules.