医原性小腸炎の臨床像と画像所見

Clinical and Imaging Features of Treatment-related Enteritis

要旨●医原性小腸炎は薬剤や医療行為に起因し，非特異的な症状と多様な内視鏡所見を呈する．非ステロイド性抗炎症薬（NSAIDs），抗腫瘍薬，免疫チェックポイント阻害薬，アンジオテンシンII受容体拮抗薬（ARB），ミコフェノール酸モフェチルなどが原因となり，潰瘍，狭窄，出血，下痢などを引き起こす．移植片対宿主病（GVHD）や放射線性腸炎，盲係蹄症候群も医原性小腸炎に含まれ，鑑別診断が重要である．診断には薬剤歴，内視鏡・病理所見，臨床経過の総合的評価が必要で，治療は薬剤中止に加え，支持療法や内視鏡的介入，免疫抑制療法を適宜選択する．

　Treatment-related enteritis, caused by drugs or medical procedures, typically presents with nonspecific symptoms and a wide range of endoscopic findings. Medications such as NSAIDs, antitumor drugs, immune checkpoint inhibitors, ARBs, and mycophenolate mofetil may cause ulceration, stricture, bleeding, and diarrhea. Other causes include GVHD, radiation enteritis, and blind loop syndrome, making differential diagnosis essential. Diagnosis requires a comprehensive evaluation of patient's drug history, endoscopic and pathological findings, and clinical course. Treatment should include supportive care, endoscopic intervention, and immunosuppressive therapy, in addition to drug discontinuation.