Enterobius vermicularis causing symptoms of appendicitis in Nepal.

This study set out to determine the prevalence of Enterobius vermicularis in surgically removed appendices and to assess the possible relation of the parasite to acute appendicitis. All 624 surgically removed appendices received in the Department of Pathology, BPKIHS, Dharan, Nepal during 2(1/2) years (August 1999-January 2002) were examined. E. vermicularis was identified in nine (1.62%) appendices from the patients with a clinical diagnosis of appendicitis. The parasite was most frequently seen in histologically normal appendices (6/71) and was rarely associated with histological change of acute appendicitis (3/539). No cases of E. vermicularis infestation occurred in appendices showing chronic inflammation or removed during the course of other surgical procedures. E. vermicularis was found more frequently in uninflamed and histologically normal appendices (8.45%) than those which were inflamed with histopathologic changes of acute appendicitis (0.56%). It may be a cause of symptoms resembling acute appendicitis although the mechanism for this does not involve mucosal invasion by the parasite.