Definition:
Rhus dermatitis is an allergic contact dermatitis caused by the Rhus (Toxicodendron) genus of plants. Members of this genus are poison ivy, poison oak, and poison sumac. The Rhus genus belongs to the Anacardiaceae family. Other plants in this family are the cashew nut tree, mango tree, Japanese lacquer tree, and marking nut tree.

All members of the Anacardiaceae family produce chemical substances called pentadecylcatechols (PDC's). Plants in the Rhus genus produce a specific PDC called urushiol in the stems, roots, canals, and skin of the fruits. When urushiol comes in contact with the skin, it causes an allergic reaction and the rash we know as poison ivy.

Pronunciation: roos • (noun)

Also Known As: poison ivy, poison oak, poison sumac

Related Resources:

Poison Ivy - Rhus Dermatitis
Find out more about this common rash.
Eczema and Dermatitis
Links to information all over the internet about eczema and dermatitis.