Erythema nodosum - Erythema nodosum

Japanese: 結節性紅斑 - けっせつせいこうはん（英語表記）Erythema nodosum

What is the disease?

Lower leg ( Hard ) It is a disease in which numerous circular or irregular erythema appear on the legs (from the knees to the ankles) that feel hard and lumpy and tender to the touch.Pathologically, it is an inflammation mainly affecting the subcutaneous fat tissue.

What is the cause?

The main causes are thought to be allergies to bacteria, viruses, fungi, etc. Other causes include medication, malignant tumors of the internal organs, Behcet's disease, tuberculosis ( Results ) , sarcoidosis, Crohn's disease, etc.

How symptoms manifest

It occurs most frequently on the front of the lower legs in young to menopausal women. It causes tenderness and sometimes pain even when not being treated, resulting in numerous erythema with hard lumps measuring 1 to 5 mm in diameter (Figure 9). In severe cases, it may spread to the thighs and arms. It often causes fever and generalized Fatigue ( Health test ) It is accompanied by systemic symptoms such as joint pain. It usually disappears within 2 to 4 weeks, but may recur.

Testing and diagnosis

A skin biopsy (a test in which a few millimeters of skin is cut and examined) was performed to confirm that the inflammation was mainly in the subcutaneous fat tissue. Induration ( Public life ) Erythema, Polyarteritis nodosa ( The examination hall of the first examination ) It is differentiated from other conditions such as lupus erythematosus, Sweet's disease, profundus lupus erythematosus, Weber-Christian disease, etc. Blood tests show an increase in white blood cells, and an increase in inflammatory responses such as erythrocyte sedimentation rate and CRP.

Treatment methods

The most important thing is to stay in bed and rest. Medications generally include nonsteroidal anti-inflammatory drugs and potassium iodide, but in severe cases Adrenal cortex ( Fukushima History ) Oral steroids are also administered. If there is an underlying disease, it is important to treat it.

What to do if you notice an illness

Since there are many diseases that have similar symptoms, we recommend that you visit a dermatologist and have a definitive diagnosis performed by skin biopsy.

Hirohiko Sueki

Figure 9 Erythema nodosum
">

Figure 9 Erythema nodosum

Source: Houken “Sixth Edition Family Medicine Encyclopedia” Information about the Sixth Edition Family Medicine Encyclopedia

Japanese:

どんな病気か

　下腿(かたい)（膝から足首まで）に円形ないし不規則形の紅斑が多発し、触ると硬いしこりと圧痛のある病気で、病理学的には皮下脂肪組織を中心とする炎症です。

原因は何か

　細菌、ウイルス、真菌などの感染アレルギーが主な原因と考えられています。そのほか、薬剤によるもの、内臓の悪性腫瘍、ベーチェット病、結核(けっかく)、サルコイドーシス、クローン病などに伴うものがあります。

症状の現れ方

　若年から更年期の女性の下腿前面に好発します。圧痛、時に何もしなくても痛みを伴う直径1～5㎜の硬いしこりのある紅斑が多発します（図9）。重症の場合は太ももや腕にまで広がることがあります。しばしば発熱、全身の倦怠感(けんたいかん)、関節痛などの全身症状を伴います。通常、2～4週で消えますが、反復することがあります。

検査と診断

　皮膚の生検（皮膚を数㎜切り取って調べる検査）を行い、皮下脂肪組織を中心とする炎症であることを確認します。病理組織学的な特徴から、バザン硬結性(こうけつせい)紅斑、結節性多発動脈炎(けっせつせいたはつどうみゃくえん)、スウィート病、深在性エリテマトーデス、ウェーバー・クリスチャン病などと区別します。血液検査では白血球の増加、赤沈やCRPなどの炎症反応の亢進がみられます。