Atypical presentation of Enterobius vermicularis in a cognitively impaired elderly patient: A case report

Enterobius vermicularis infection (enterobiasis) is a common intestinal parasitosis, typically characterized by perianal pruritus, and is most prevalent in children. Diagnosing enterobiasis in cognitively impaired individuals, who may not report typical symptoms, poses a diagnostic challenge. We report the case of an 86-year-old Japanese woman with cognitive impairment who was admitted for a tibial fracture. During a routine diaper change, several motile, thread-like organisms were incidentally observed in her perianal and perivaginal areas. Microscopic examination identified the organisms as gravid female E. vermicularis. The patient reported no pruritus ani or insomnia, and was successfully treated with a two-dose regimen of pyrantel pamoate. The follow-up adhesive tape tests confirmed clearance of the parasites. This case highlights that enterobiasis can be clinically silent in elderly patients with cognitive impairment, a population at increased risk due to potential difficulties with hygiene and an inability to report symptoms. Clinicians and caregivers should remain alert to enterobiasis in cognitively impaired elderly patients to ensure timely diagnosis and prevent transmission.