Abstract
            Introduction: Enterobius vermicularis, commonly known as pinworm, is one of the most prevalent intestinal nematodes of  humankind belonging to the Oxyuridae family. It is a small, white or transparent, threadlike roundworm. The length of the male  worm is 2 to 3 mm and the female worm is 3 to 8 mm in length. This study was performed to determine the prevalence of E.  vermicularis and its relationship with disease symptoms, allergic disease symptoms, and eosinophilia in children aged one to six  years in Marand city of East Azerbaijan province, Iran.  
  Methods: In this descriptive-analytical study, 200 children were studied using systematic random sampling. Data collection  method was based on a questionnaire, peripheral blood smear, and Scotch tape test. In the designed questionnaire, children’s  characteristics such as gender and age and parents’ characteristics including job and level of education were recorded. Peripheral  blood smear slides were obtained from each child and examined for eosinophilia by a hematologist. Scotch test samples were  prepared by parents after providing the necessary training on its sampling method and then examined in the laboratory for the  presence of E. vermicularis eggs by a parasitologist.  
  Results: In this study, 64 (32%) children were diagnosed with oxyuriasis. The prevalence of oxyuriasis was 36.5% in boys and  43.7% in girls. There was no significant relationship between oxyuriasis and its symptoms. Additionally, there was no significant  relationship between oxyuriasis and allergic disease symptoms. Fourteen children had eosinophilia (7%), of which 9 (64%) were  infected with E. vermicularis. There was a significant relationship between E. vermicularis infection and eosinophilia (P ˂ 0.05).  
  Conclusion: According to the results of the study and the importance of the issue for the control and prevention of this disease,  it is suggested that people should be provided with the necessary information about the life cycle, ways of transmission, and  especially ways to prevent E. vermicularis infestation, and basic measures should be taken to improve the economic situation  of the people of the region and to promote public and personal health through public education. Finally, medical treatment of  patients and their families should be considered at the same time.