多彩な内視鏡所見を呈し，metronidazoleとtinidazole耐薬性であったアメーバ性大腸炎の1例

Metronidazole and Tinidazole-resistant Amebic Colitis with Various Endoscopic Findings, Report of a Case

要旨　大腸内視鏡検査で多彩な異常所見を経時的に観察でき，metronidazoleとtinidazoleに効果を示さずdehydroemetineで軽快した蛋白漏出性胃腸症を伴ったアメーバ性大腸炎の1例を経験した．73歳の男性，主訴が水様粘液性下痢，両下肢の浮腫で1983年4月18日当科へ入院．約7か月前に内視鏡所見から潰瘍性大腸炎として治療がなされた．今回の内視鏡所見はS状結腸に限局性（約10cm）の地図状の異常発赤部とその中に白色調の粘膜が島状に残ったような奇異なものであった．便からE. histolyticaのcystを検出（生検組織：陰性）．metronidazoleとtinidazoleで効果なくemetine 45mg/日（筋注，10日間）で軽快した．¹³¹I-RISAで証明された蛋白漏出性胃腸症も治った．

　A 73 year-old man with chief complaints of diarrhea and lower limb edema was admitted to our hospital on April 18, 1983. Ten months prior to this admission, he had frequent watery mucous diarrhea. Under a diagnosis of ulcerative colitis, oral salazopyrine and steroid enema therapy were given. On this admission, the colonofiberscopic finding showed geographical abnormal red areas mainly from middle Houston valve to sigmoid, much different from the previous findings (edema, hyperemia and erythema.) Numerous cysts of Entamoeba histolytica were found from mucous stool and the diagnosis of amebic colitis was made with negative serological test for E. histolitica. Metronidazole and tinidazole were administered without effect. After combination therapy with dehydroemetine 45mg/day i.m. for 10 days, the symptom subsided finally. Protein-loosing gastroenteropathy (T.P. 4.8g/dl) confirmed by ¹³¹I-RISA test on admission was also cured.

　Being ineffective of treatment with metronidazole and tinidazole, it is considered that there exists ameba resistant to these drugs although resistant strain to metronidazole has not been found in in vitro test yet.

　It is not easy to find cyst from patient with chronic intestinal amebiasis, even if amebiasis is suspected from clinical symptoms and endoscopic findings. Definite diagnosis is often difficult. Furthermore, many patients with chronic intestinal amebiasis are treated as ulcerative colitis from the beginning, so it is often experienced that characteristic endoscopic findings are much modified just as seen in our patient. This is considered a main cause for making the diagnosis difficult.