Enterobius vermicularis (pinworm), one of the most common helminthic infections,¹  generally inhabits the large intestine but is of low pathogenicity. Occasionally, however, ova can be found in ectopic sites in the peritoneal cavity (often as asymptomatic granules) and sometimes in the appendix.² Perianal itching in children is most often due to enterobiasis.³ Pelvic inflammatory disease can result from E. vermicularis infection.⁴

The cellophane tape procedure (CTP), which is the basis for diagnosis of enterobiasis (oxyuriasis) is improved by lacto-phenol cotton blue staining;⁵ the frequency of enterobiasis is thought to have decreased in the U.S.⁶ Three CTP exams detect 90% and five exams detect 99% of pinworm infections.^7,8 A simple screening program is effective for elimination of pinworm from institutionalized patients.⁹ Testing for antibodies is not promising.¹⁰ Family status and personal hygiene are probably important in transmission of pinworm infection.¹¹ Both normal and inflamed appendices can be infested.¹² Ectopic enterobiasis is well recognized.^13,14 A review on E. vermicularis symptoms, diagnosis and treatment is available.¹⁵