Pruritus Ani - Describes this condition of anal itching, and treatment. - http://www.skinsite.com/info_pruritus_ani.htm
Invisible Itches: Insect and Non-Insect Causes - Article about biting arthropods and other causes of irritations of unknown origin. - http://www.ca.uky.edu/agc/pubs/ent/ent58/ent58.pdf
NCI: Pruritus - Includes ways to relieve itching and types of cancer and treatments that may increase the risk of developing pruritus. - http://www.cancer.gov/cancerinfo/pdq/supportivecare/pruritus/Patient