Pinworms are parasites in human rectum. These worms get inside the body by swallowing their eggs. Eggs develop and produce pinworms. The female can leave the intestine through anus and ay eggs at the surrounding areas of anus. These eggs and pinworms cause intense itching. Antiparasite medicines like Albendazole can work. For itching, topical creams containing hydrocortisone can be used. Ointments like Desitin, Balmex can also help to reduce itching.