Necrotizing amebic colitis: the plea for an early diagnosis.

Abstract

Dear Sir, I read with interest the paper titled ‘‘Necrotizing amebic colitis in a child’’ by Choudhury et al. [1]. Living in an area which is endemic for the parasite E. histolytica, I would like to share a few thoughts on this fulminant disease based on our experience of treating an 11-month-old child with necrotizing amebic colitis (NAC) of the right colon who was referred to us 7 days after the onset of a bloody diarrhea without anti-amebic treatment. There is a reluctance to consider amebic colitis as a diagnosis in small children with bloody diarrhea. This has frequently led to delays in the diagnosis, with an attendant high mortality and morbidity [2, 3]. This is particularly true of NAC, which is more common in the pediatric population [2, 3, 4]. The reported child had a history consistent with amebic colitis, but probably never received appropriate therapy pre-operatively. The clinical diagnosis of NAC can also prove to be difficult. Routine examination of the stool for ova and cysts is often unproductive [5]. Best results are obtained by the examination of a fresh smear from the ulcer, within the hour, by experienced personnel [6]. Proctosigmoidoscopy can be helpful in demonstrating the characteristic ulcers of amebic colitis [5, 7], but in necrotizing colitis the appearance may be similar to nonspecific inflammatory bowel disease [8]. Careful barium enema studies have been reported to be of value in establishing the diagnosis in one report [9], however, other reports contradict this [5]. Serological tests have now emerged as reliable indicators of invasive amebiasis, but frequently take too long to provide the results. Thus, a pre-operative diagnosis of NAC is seldom made. The best method to reduce the mortality and morbidity of the condition would be to increase the awareness of the primary care physicians of the possibility of NAC, and urge them to pursue diligent investigations and start anti-amebic therapy early. Adding metronidazole to the treatment of children with bloody diarrhea who are unresponsive to the standard anti-Shigella therapy should be considered in light of the risk of NAC, especially in small children.