腹痛を呈した上腸間膜動脈（superior mesenteric artery: SMA）に限局した高安動脈炎の一例を経験したので，文献的考察を加えて報告する．症例は17歳，男性．心窩部痛・右背部痛を認め，近医を受診し，その際施行した体外式腹部超音波検査（ultrasound: US）でSMA の壁肥厚が疑われ，当院総合診療科を紹介受診した．身体診察では上腹部正中に軽度圧痛を認め，血液生化学検査では血沈（60min）35mm, CRP 3.92mg/dL と軽度上昇を認めた．US では，腹痛を訴える部位に一致してSMA 起始部にびまん性の壁肥厚を認め，血管炎が疑われた．胸部造影・上腹骨盤部単純造影CT 検査（computed tomography: CT）ではSMA 周囲に造影効果を認める軟部影を認め，18F-FDGPET（18F-fluorodeoxyglucose positron emission tomography: PET）/CT 検査ではSMA 起始部付近に腫大と軽度のFDG 集積を認め，動脈炎による集積で矛盾しない所見であった．以上のことから，SMA に限局した高安動脈炎と診断した．ステロイド治療を開始し腹痛は速やかに消褪すると共に，US 所見にも改善がみられた． ; We report the case of a 17-year-old male who visited a hospital complaining of epigastric and right back pain. Thickening of the wall of the superior mesenteric artery （SMA) was suspected by ultrasound （US), and he was referred to our hospital. Physical examination revealed median upper abdominal tenderness. Laboratory tests showed an erythrocyte sedimentation rate （60 min) of 35 mm and C-reactive protein of 3.92mg/dL. US examination in our hospital showed diffuse wall thickening at the origin of the SMA. Because the location of the pain and the affected area identified by US were the same, we suspected angiitis. An enhanced area around the SMA was revealed by computed tomography. 18F-fluorodeoxyglucose positron emission tomography/computed tomography showed swelling at the origin of the SMA and mild accumulation of fluorodeoxyglucose. He was diagnosed with Takayasu arteritis involving the SMA. Steroid therapy was started, and his abdominal pain and US findings improved.