S5135 A Squirmy Surprise: Enterobiasis vermicularis Treatment in Pregnancy

Introduction: Enterobiasis vermicularis, colloquially known as pinworms, are the most common helminthic infection in the United States. Most Enterobius infections are asymptomatic, but commonly present with nocturnal perianal itching. Anthelminthic agents are typically first line therapies, but there is a paucity of data in treating pregnant patients. Here, we discuss a case of a 25-year-old pregnant woman, who was found to have incidental pinworms on endoscopic evaluation done for rectal bleeding. Case Description/Methods: A 25-year-old woman, G1P0 at 23 weeks with no significant past medical history, presented to the Emergency Department for evaluation of abdominal pain with bloody diarrhea. Patient was hemodynamically stable. Due to severity of symptoms, an un-sedated outpatient sigmoidoscopy was performed which revealed pinworms. Diagnosis was made on appearance. Rectal bleeding was attributed to benign internal hemorrhoids. No antiparasitic agent was prescribed due to absence of symptoms. She returned later to request treatment prior to delivery. Maternal fetal medicine was consulted, and patient was given pyrantel pamoate 11 mg/kg in her third trimester at 34- and 36-weeks gestation. No test of cure was performed. Discussion: Albeit rare, pinworm infection in pregnancy can increase maternal morbidity and result in fetal complications. Despite this risk, treatment in pregnant patients is reserved only for severe symptoms. Rectal bleeding is not typically associated with infection. Anthelminthic agents are generally considered safe in pregnancy but are classified as pregnancy category C by the FDA based on animal studies. Pyrantel pamoate is preferred to albendazole and mebendazole due to poor systemic absorption limiting fetal exposure. Treatment is preferred in the third trimester due to decreased fetal risk. In order to prevent reinfection, hygienic measures should be implemented to include washing bedsheets, fingernail clipping and, frequent handwashing. Due to the endemic nature of pinworms and their potential complications, physicians need greater awareness and understanding on treatment in pregnancy.