8) 好酸球性胃腸炎

Eosinophilic Gastroenteritis

要旨　好酸球性胃腸炎は消化管に好酸球浸潤を来す比較的まれな疾患であり，小腸はその好発部位である．小腸X線では空腸を主体として広範囲の小腸にKerckring皺襞の密度上昇や浮腫性肥厚，結節状の隆起形成，伸展不良，蠕動・分泌の亢進等を認めるが，びらんや潰瘍がみられることは少ない．内視鏡では粘膜面の変化に乏しく，浮腫，発赤，皺襞の密度上昇以外に明らかな異常として捉えられないことが多い．CTや腹部超音波検査は腸壁肥厚や腹水を検出するうえで有用である．末梢血中好酸球増多や小腸の広範な伸展不良がみられる場合に，本症を念頭に置く必要がある．治療には副腎皮質ステロイドが著効を示すが，抗アレルギー剤も有効である．まれに狭窄や穿孔を来すこともあり，早期に診断し不可逆的な変化が出現する前に治療を行うことが重要である．

　Eosinophilic gastroenteritis is a relatively rare inflammatory disorder in which the small intestine is often involved. By enteroclysis, accentuation and shortening of the interval of Kerckring folds, nodular prominences, narrowing of the lumen, hypermotility, and hypersecretion are observed. Erosions or ulcers are usually absent. Endoscopic findings of the mucosal surface are often minute; edema, injection, or shortening of the interval of Kerckring folds are the only abnormalities. CT and abdominal ultrasonography are useful modalities to demonstrate intestinal wall thickening and ascites. In cases with eosinophilia or intestinal narrowing, eosinophilic gastroenteritis should be born in mind. Although corticosteroid is very effective for this disorder, anti-allergic agents are also useful. Irreversible changes such as stenosis or perforation may occur if not properly treated, so early diagnosis and treatment is important.