Postgraduate Meditine: Patient Notes: Itching 
Basic information on causes and treatments.
http://www.postgradmed.com/issues/1997/08_97/pn_itch.htmPruritus
Medical overview from the Canadian Encyclopedia of Dermatology.
http://www.fortunecity.com/marina/victory/11/pruritus.htm
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
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
Pruritus Ani
Describes this condition of anal itching, and treatment.
http://www.skinsite.com/info_pruritus_ani.htm
