4)強皮症（全身性硬化症）

Gastrointestinal Involvement in Patients with Scleroderma/Systemic Sclerosis

　強皮症(全身性硬化症)の消化管病変は，固有筋層における膠原線維の増生と筋組織の萎縮に起因する消化管の拡張と蠕動の低下に要約される．食道には50～90％の症例で管腔拡張，食道裂孔ヘルニア，逆流性食道炎などがみられる．胃病変は少なく，小腸には約50％の症例で十二指腸・空腸の拡張や偽性腸閉塞などの病変がみられ，X線では特徴的なhide-bound appearanceやcoiled-spring appearanceを呈する．大腸には10～50％の症例で憩室や便秘および宿便性潰瘍などがみられ，X線ではハウストラの減少・消失が認められる．また，強皮症と原発性胆汁性肝硬変との関連性が示唆されている．

　The gastrointestinal manifestations in patients with scleroderma (systemic sclerosis) are characterized by dilation of the gastrointestinal tract and reduced peristalsis caused by muscle atrophy and proliferation of collagen fibers in the muscularis propria. Esophageal involvement is observed in 50-90 ％ of patients. It manifests itself with dilation of the esophagus, hiatal hernia, while reflux esophagitis. The stomach is rarely involved, but small bowel manifestations are found in as many as 50 ％ of patients. Radiographic features of small bowel involvement with scleroderma is characterized by dilation of the duodenum and jejunum with marked crowding of the valvulae conniventes, showing hide-bound appearance or coiled-spring appearance. Colonic involvement is seen in 10-50 ％ of patients. It presents diverticula, constipation, stercoral ulcerations, or loss of haustration. In addition, an association between scleroderma and primary biliary cirrhosis has been suggested.