Hello dear, Thank you for your contact to health care magic. I read and understand your concern. I am Dr Arun Tank answering your concern. Pin worm is caused by enterobius vermicularis infection. It will not caused because of the junk foods and roadside foods. But you probably exposed to the person infected with this parasite. The drugs you are taking is right and you should continue with it. Many a times a single dose won t work and you require a second dose at the end of week. Second dose mostly cures your infection. Please adopt good hand washing practice otwrwise it will spread to the rest of the people in your family. It can also spread via respiratory route so please protect your family through air borne infection. I will be happy to answer your further concern on bit.ly/DrArun. Thank you, Dr Arun Tank Infectious diseases specialist, HCM.