Pinworms are very common nematodes in children. Located in the lumen of the colon, they can remain asymptomatic for a long time or cause digestive disorders such as mild abdominal pain or diarrhea, but especially anal pruritus, which often has repercussions on family and school behavior. This parasite rarely causes serious lesion such as minute ulcers and mild catarrhal inflammation of the intestine. Sometimes, invasion of the superficial mucosa provokes a granulomatous reaction.

The diagnosis is based on the adhesive cellophane swab, which finds the characteristic eggs and more rarely by parasitological examination of the stools which can reveal eggs and also adult worms, small white nematodes (1cm long). Treatment is based on imidazole derivatives and hygiene measures (treatment of the whole family the same day, keeping hands and finger nails clean, frequent bathing and laundering of night clothes…)

But it happens that pinworms are found in ectopic localizations as in the genitals, mostly in young girls [1]. Female pinworms lay eggs on the anal margin and can migrate to the nearly genitals.  So, they can be found in the vagina [2-4], from where they can go up the genital tract (uterus, fallopian tubes, ovaries) [5] and also in the peritoneum [6] In these unusual locations, pinworms often cause an inflammatory reaction, such as endometritis, salpingitis or pyosalpinx [7,8] and which can sometimes evoke cervical cancer [9] or genital abscess [10]. A uterine endometrial Enterobius vermicularis infestation was the cause of infertility, the woman conceived after treatment of the parasitosis [11].

In these genital sites, the diagnosis is rarely mentioned on the symptomatology such as nocturnal pollakiuria, dysuria, acute urinary infection [12], enuresis, vaginal pruritus, vulvar oedema [13].

It is established either by examining the vaginal smear which finds the eggs [14] or by pathological examination of an excision of an inflammatory type lesion where one finds eggs or sections of adult worms [10]. In the vulva, a granulomatous hyperplasic reaction due to pinworms is uncommon [15] and can evoke a differentiated carcinoma [16]. Such a diagnosis was made on pathological examination of a vulvar biopsy in a 70-year-old woman treated for vulvar cancer [17] as in the case reported above. Localization in the Bartholin glands has already been reported [18]. In all these cases, the inflammatory phenomena resolved by the appropriate anthelmintic treatment.