慢性感染性腸炎の病態と画像診断—梅毒を中心に

Pathophysiology and Imaging Diagnosis of Chronic Infectious Enteritis with a Focus on Syphilis

要旨●本邦における梅毒報告数は近年爆発的に増加しており，梅毒は消化器領域の日常診療でも遭遇しうる疾患である．消化管梅毒で最も多い胃梅毒の内視鏡像は胃前庭部に癒合傾向のある浅い不整形潰瘍やびらんが多発し，管腔の狭小化はみられるものの送気伸展が得られることが特徴である．内視鏡所見および生検による病理組織学的診断をもって確定診断とされるが，HE染色は非特異的所見のみであり，抗TP抗体を用いた免疫組織化学染色が有用である．本稿では梅毒以外に慢性感染性腸炎として遭遇しうるサイトメガロウイルス感染症，アメーバ性腸炎，消化管結核，COVID-19腸炎の病態と画像診断について解説する．

　The diagnosis of chronic infectious enteritis is basically confirmed by proving the causative micro-organism. However, in many cases, identifying the causative micro-organism is difficult, and differentiating malignant tumors and inflammatory bowel disease becomes challenging. A misdiagnosis may lead to unnecessary treatment, and the delay in diagnosis may affect the patient's prognosis. To ensure early diagnosis and treatment, it is important to be familiar with the characteristic endoscopic images of each disease and to be able to differentiate them. The present article describes the pathogenesis and imaging diagnosis of chronic infectious enteritis, including cytomegalovirus infection, amebic enteritis, intestinal tuberculosis, and COVID-19 enteritis, with a focus on syphilis.