Go Ask Alice!: Poison Ivy, Oak and Sumac -
Advice on symptoms and treatment, including when to seek emergency medical care. From Columbia University Health Education Program.
http://www.goaskalice.columbia.edu/1354.html

Outsmarting Poison Ivy -
 Learn to prevent and control reactions and common treatments.
http://pediatrics.about.com/

Poison Ivy: an Exaggerated Immune Response to Nothing Much -
 Brief technical article on allergic reactions to poison ivy, including physiology, treatment options and links to related information.
http://www.bio.umass.edu/immunology/poisoniv.htm

Poison Ivy, Oak, and Sumac Information Center -
Information on the causes, prevention, and treatment of the itching and painful rashes associated with contact of the oil called urushiol that is found in these plants. Includes numerous links to other information sources and websites on commercial products.
http://poisonivy.aesir.com/

Poison Ivy Tutorial -
 Pictures, reference, and quiz on poison ivy's identification, rash, treatment, and the urushiol oleoresin.
http://www.cattail.nu/ivy/

Poison Ivy/Oak/Sumac -
 General information on avoiding and treating reactions from exposure.
https://www.yourhealth.com/CRS/HBL/hbl_poisivy_crs.htm

RXinsider -
 Short informational monograph on poison ivy/oak/sumac and their treatment.
http://rxinsider.com/monographs/poison_oak_and_ivy.htm

Survive Outdoors Inc. -
Detailed pictures of poison ivy rashes and lookalikes.
http://www.surviveoutdoors.com/emergency/poisonivy.asp