Urushiol is an oily organic allergen found in various plants including plants of the genus Toxicodendron (e.g., poison ivy, poison oak, and poison sumac). It causes a skin rash known as urushiol-induced contact dermatitis (also called Toxicodendron dermatitis and Rhus dermatitis). It is the medical name given to allergic rashes produced by the oil urushiol, which is a yellow liquid that is miscible in alcohol but nearly insoluble in water. It is a mixture of several closely-related organic compounds.

 

Normally, it takes about 24 hours for the rash to first appear; for those with severe reactions it worsens during the next few days. The American Academy of Dermatology estimates that there are up to 50 million cases of urushiol-induced dermatitis annually in the United States alone.

 

If you are exposed, according to the FDA, you should quickly (within 10 minutes):

Commercial products like Zanfel, Ivy Cleanse Towelettes, and Tecnu Extreme Poison Ivy Scrub, are also available over-the-counter.

Newer medications that are supposed to target symptoms include:

 

References:

• http://en.wikipedia.org/wiki/Urushiol

• http://pediatrics.about.com/cs/conditions/a/poison_ivy.htm

• http://en.wikipedia.org/wiki/Urushiol-induced_contact_dermatitis