Appendiceal Enterobius vermicularis infestation in adults.

The objective of this study is to evaluate the incidence of Enterobius vermicularis in the appendices of the adult population and a possible relationship between E. vermicularis and acute appendicitis. E. vermicularis was identified in 18 (2%) of 890 patients. Six hundred sixty-five operations were performed for presumptive diagnosis of acute appendicitis, and E. vermicularis was found in 12 (2%) patients. The histopathological examination revealed acute inflammatory cells in four cases (33%). Three of these four specimens included luminal ova and one E. vermicularis. Histopathological examination of six cases revealed E. vermicularis in 225 incidental appendectomies with no evidence of either acute or chronic inflammatory cells. This study suggests a relationship between the presence of E. vermicularis ova and acute inflammation, but the presence of the pinworm in the lumen of the appendix is coincidental. On the other hand E. vermicularis in the appendix lumen can cause symptoms of acute appendicitis.