Review Question - QID 105445

Enterobius vermicularis, also known as the pinworm or seatworm, is a helminthic parasite that presents most commonly with perianal itching as well as vaginal itching. This patient's diarrhea is likely related to her recent antibiotic use and is not related.

The pinworm (Enterobius vermicularis) is a roundworm (or nematode) that commonly presents clinically in children with perianal or vulvar pruritis and restless sleep. In cases of recurrent infection, the vagina has been found to serve as a possible reservoir for the worm, and thus it is possible for this parasite to present initially or recur with vulvar itching with or without perianal itching. The diagnosis can be confirmed with the scotch tape test which can show the eggs/organism. The treatment is albendazole.

Incorrect Answers:
Answer 1: Candida albicans presents with vaginal pruritus and a thick, white discharge. It would be unlikely in this patient who initially had perianal symptoms; however, her recent amoxicillin use is a risk factor for a yeast infection.

Answer 3: Gardnerella vaginalis can cause bacterial vaginosis which presents with a thin, white discharge and a fishy vaginal odor on exam; however, it does not cause pruritus. It is diagnosed with a wet mount and treated with metronidazole.

Answer 4: Giardia lamblia is associated with drinking unfiltered water and presents with profuse and fatty diarrhea. It is diagnosed with a stool ova and parasite exam and treated with metronidazole.

Answer 5: Herpes simplex virus presents with painful vesicles/ulcers and tender lymphadenopathy usually on the genitals. The diagnosis is usually made clinically and treatment involves acyclovir.

Bullet Summary:
Enterobius vermicularis (pinworm) can cause perianal itching and vaginitis.